Multidrug-resistant commensal Escherichia coli in children, Peru and Bolivia.Using a rapid screening method, we investigated the prevalence in fecal carriage of antimicrobial drug-resistant Escherichia coli Escherichia coli (ĕsh'ərĭk`ēə kō`lī), common bacterium that normally inhabits the intestinal tracts of humans and animals, but can cause infection in other parts of the body, especially the urinary tract. in 3,174 healthy children from 4 urban settings in Peru and Bolivia. High resistance rates were observed for ampicillin ampicillin (ăm'pĭsĭl`ĭn), a penicillin-type antibiotic that is effective against both gram-negative microorganisms and gram-positive microorganisms such as Escherichia coli. (95%), trimethoprim-sulfamethoxazole (94%), tetracycline tetracycline (tĕ'trəsī`klēn), any of a group of antibiotics produced by bacteria of the genus Streptomyces. They are effective against a wide range of Gram positive and Gram negative bacteria, interfering with protein (93%), streptomycin streptomycin (strĕp'tōmī`sĭn), antibiotic produced by soil bacteria of the genus Streptomyces and active against both gram-positive and gram-negative bacteria (see Gram's stain), including species resistant to other (82%), and chloramphenicol chloramphenicol (klōr'ămfĕn`əkŏl'), antibiotic effective against a wide range of gram-negative and gram-positive bacteria (see Gram's stain). It was originally isolated from a species of Streptomyces bacteria. (70%). Lower resistance rates were observed for nalidixic acid nalidixic acid /nal·i·dix·ic ac·id/ (nal-i-dik´sik) a synthetic antibacterial agent used in the treatment of genitourinary infections caused by gram-negative organisms. na·li·dix·ic acid n. (35%), kanamycin kanamycin /kan·a·my·cin/ (kan?ah-mi´sin) an aminoglycoside antibiotic derived from Streptomyces kanamyceticus, effective against aerobic gram-negative bacilli and some gram-positive bacteria, including mycobacteria; used as the (28%), gentamicin gentamicin /gen·ta·mi·cin/ (jen?tah-mi´sin) an aminoglycoside antibiotic complex isolated from bacteria of the genus Micromonospora, (21%), and ciprofloxacin ciprofloxacin /cip·ro·flox·a·cin/ (sip?ro-flok´sah-sin) a synthetic antibacterial effective against many gram-positive and gram-negative bacteria; used as the hydrochloride salt. cip·ro·flox·a·cin n. (18%); resistance to ceftriaxone ceftriaxone /cef·tri·ax·one/ (cef?tri-ak´son) a semisynthetic, ß–resistant, third-generation cephalosporin effective against a wide range of gram-positive and gram-negative bacteria, used as the sodium salt. and amikacin was uncommon (<0.5%). In a random sample of 1,080 resistant E. coil isolates, 90% exhibited a multidrug-resistance (MDR MDR, n See multidrug resistance. MDR, n the abbreviation for minimum daily requirement, specifically the Minimum Daily Requirements for Specific Nutrients compiled by the United States Food and Drug Administration. ) phenotype. The 2 most common MDR phenotypes (ampicillin/tetracycline/trimethoprim-sulfamethoxazole and ampicillin/tetracycline/trimethoprim-sulfamethoxazole/chloramphenicol) could be transferred en bloc en bloc adv. As a unit; all together: "I have been drawing our attention to the public and private qualities of the several arts lest they be treated en bloc" William H. Gass. in conjugation conjugation, in genetics conjugation, in genetics: see recombination. conjugation, in grammar conjugation: see inflection. experiments. The most common acquired resistance genes were [bla.sub.TEM TEM 1. transmission electron microscope. 2. triethylenemelamine. 3. transmissible encephalopathy of mink. ], tet(A), tet(B), drfA8, sul1, sul2, and catl. These findings underscore the magnitude of the problem of antimicrobial drug resistance in low-resource settings and the urgent need for Surveillance and control of this phenomenon. ********** The spread of microbial microbial pertaining to or emanating from a microbe. microbial digestion the breakdown of organic material, especially feedstuffs, by microbial organisms. drug resistance is a global public health challenge, which impairs the efficacy of antimicrobial agents Antimicrobial agents Chemical compounds biosynthetically or synthetically produced which either destroy or usefully suppress the growth or metabolism of a variety of microscopic or submicroscopic forms of life. and results in substantial increased illness and death rates and healthcare-associated costs (1-3). In low-resource countries, the extent and the impact of the phenomenon tend to be even larger than in industrialized in·dus·tri·al·ize v. in·dus·tri·al·ized, in·dus·tri·al·iz·ing, in·dus·tri·al·iz·es v.tr. 1. To develop industry in (a country or society, for example). 2. countries. In fact, high resistance rates have often been reported in surveillance studies dealing with clinical isolates (1,4,5) and in prevalence studies of commensal commensal /com·men·sal/ (kom-men´sil) 1. living on or within another organism, and deriving benefit without harming or benefiting the host. 2. a parasite that causes no harm to the host. bacteria taken as indicators to estimate spread of acquired resistance (6-15). Moreover, in low-resource countries the impact of antimicrobial drug resistance on illness and death rates tends to be greater because of the high prevalence of bacterial infections and the major role of antimicrobial agents in combating infectious diseases infectious diseases: see communicable diseases. (1,3,4,16,17). The high antimicrobial drug resistance rates observed in low-resource countries are likely due to a combination of several factors, among which irrational antimicrobial drug usage and conditions of poor sanitation are thought to play a major role, even if the relative importance of additional factors remains unclear (1,4,8,9). ANTRES (Towards Controlling Antimicrobial Use and Resistance in Low-Income Countries: An intervention Study in Latin America Latin America, the Spanish-speaking, Portuguese-speaking, and French-speaking countries (except Canada) of North America, South America, Central America, and the West Indies. ) is a research project that aims to investigate this phenomenon on a large scale. The project is carried out in 2 Latin American countries List of American countries Nations:
We report the results of the baseline study, carried out at the beginning of the project, to assess the antimicrobial drug resistance rates in the studied areas. Very high resistance rates to several antimicrobial agents were observed in commensal bacteria from the population of each area. Strains showing multidrug-resistance (MDR) phenotypes were widely disseminated. Materials and Methods Study Design and Population The study population was represented by healthy children 6-72 months of age from 4 urban areas, 2 in Bolivia (Camiri, Santa Cruz Department Santa Cruz, with an area of 370,621 km², is the largest of the nine constituent departments of Bolivia. In the 2001 census, it reported a population of 2,029,471. The capital is the city of Santa Cruz de la Sierra. ; Villa Montes mon·tes n. Plural of mons. , Tarija Department Tarija is a department in Bolivia. It is located in south eastern Bolivia bordering Argentina to the south and Paraguay to the east. According to the 2001 census, it has a population of 391,226 inhabitants. It has an area of 37.623 km². ) and 2 in Peru (Yurimaguas, Loreto Department; Moyobamba, San Martin Department). The urban areas were communities of [approximately equal to]25,000 to 30,000 inhabitants
The game is based loosely on the concepts from SameGame. who had comparable demographic and socioeconomic characteristics. Eight hundred children from each area were enrolled in the study to cover at least 25% of all households with children in the target age cohort. Only children who had not had diarrhea (as defined by the World Health Organization [18]) during the previous 24 hours were eligible for inclusion in the study. In each household, the youngest recruitable child in the target age cohort was selected. The studied households were selected with a modified cluster sampling Cluster sampling is a sampling technique used when "natural" groupings are evident in a statistical population. It is often used in marketing research. In this technique, the total population is divided into these groups (or clusters) and a sample of the groups is selected. : detailed maps outlining the distribution of households were obtained from each study area, and each city was divided into 80 small clusters. In each cluster a number of households selected at random were visited until 10 children were reached. A rectal swab was obtained from each child enrolled in the study, after informed consent was obtained from parents or other legal guardians. Before the sample was obtained, adult members of the household were interviewed to collect information on the family's socioeconomic and cultural setting, the household antimicrobial drug use, and the health status of the selected child. In each country, full ethical clearance was obtained from the qualified authorities who had revised and approved the study design. The overall acceptance rate was >95% in all studied areas. Rectal swabs were obtained from a total of 3,174 children (Figure 1): 794 from Camiri and 790 from Villa Montes, Bolivia; 797 from Yurimaguas, and 793 from Moyobamba, Peru. The study participants were 6-72 months of age (mean 34.7 [+ or -] 18.2 months; median age 33.5 months).The female:male ratio was 0.95. No significant differences in age or sex were observed among children enrolled from the different areas. The study was carried out for 4 months (August-November 2002). In each area, the sampling period was not longer than 7 weeks. Screening for Resistant Escherichia coli in Commensal Microbiota Microbiota (human) Microbial flora harbored by normal, healthy individuals. A number of microorganisms have become adapted to a particular site or ecologic niche in or on their host. Rectal swabs, stored in Amies transport medium (Oxoid, Milan, Italy), were transferred in a cold box to the laboratory of the corresponding district hospital within 3 hours of collection. The 4 laboratories participate in national quality control programs. A training phase and a pilot study preceded the survey. Three European investigators (AB, MB, LP) participated in the sample analysis in the 4 laboratories. This approach was chosen to limit variability in the microbiologic procedures during the field studies. Screening for antimicrobial-resistant E. coli E. coli: see Escherichia coli. E. coli in full Escherichia coli Species of bacterium that inhabits the stomach and intestines. E. coli can be transmitted by water, milk, food, or flies and other insects. in the fecal microbiota was carried out by a direct plating method, as described previously (7,19). This method is preferred because it correlates well with methods based on testing of randomly collected colonies from primary stool culture Stool Culture Definition Stool culture is a test to identify bacteria in patients with a suspected infection of the digestive tract. A sample of the patient's feces is placed in a special medium where bacteria is then grown. , but it is more sensitive (11,19). Briefly, each swab was spread on a McConkey agar no. 3 plate (Oxoid) to yield uniform growth, and antimicrobial drug-containing disks were directly placed onto the seeded plate. Antimicrobial agents tested included ampicillin, ceftriaxone, tetracycline, trimethoprim-sulfamethoxazole, chloramphenicol, streptomycin, kanamycin, gentamicin, amikacin, nalidixic acid, and ciprofloxacin (Oxoid). After incubation at 37[degrees]C for 12 to 14 hours, plates were inspected for growth, and inhibition zone diameters were measured. The presence of a growth inhibition Growth inhibition (GI) is a medical term pertaining to cancer therapy and the specific reduction in growth of tumors and oncogene cells by a chemical compound, mechanical therapy (e.g. zone larger than the established breakpoint The location in a program used to temporarily halt the program for testing and debugging. Lines of code in a source program are marked for breakpoints. When those instructions are about to be executed, the program stops, allowing the programmer to examine the status of the program diameter was considered to indicate susceptibility to that agent. The presence of a growth inhibition zone smaller than the breakpoint diameter, the absence of any inhibition zone, or the presence of isolated colonies growing inside an inhibition zone of any size was considered indicative of resistance. In the latter case, however, resistance was considered not to be represented in the dominant flora. Breakpoints were as previously described for ampicillin, tetracycline, trimethoprim-sulfamethoxazole, chloramphenicol, amikacin, nalidixic acid, and ciprofloxacin (19), and 14 mm, 12 mm, 12 mm, and 14 mm for kanamycin, streptomycin, gentamicin, and ceftriaxone, respectively (A. Bartoloni, unpub, data). Only bacterial growth Bacterial growth The processes of both the increase in number and the increase in mass of bacteria. Growth has three distinct aspects: biomass production, cell production, and cell survival. exhibiting a shape typical of E. coli was considered valid for the analysis. Specially prepared forms were used to record microbiologic results, including growth features and susceptibility patterns. Confluent con·flu·ent adj. 1. Flowing together; blended into one. 2. Merging or running together so as to form a mass, as sores in a rash. bacterial growth was obtained from 3,130 (99%) of the 3,174 collected rectal swabs (Figure 1). In a few cases insufficient growth (11 swabs) or noncoliform growth (33 swabs) was observed. From each plate and for each drug, the putatively resistant coliform coliform /col·i·form/ (kol´i-form) pertaining to fermentative gram-negative enteric bacilli, sometimes restricted to those fermenting lactose, e.g., Escherichia, Klebsiella, or Enterobacter. growth (i.e., a pool of the colonies grown inside the zone of inhibition or a loopful of the microbial lawn grown in proximity of the disk) were collected (n = 18,042) (Figure 1). Of these, a random sample (10%-25% for each drug, depending on the prevalence of the resistance phenotype) were subjected to confirmatory analysis for resistant E. coli (Figure 1) by using the API20E identification system (bioMerieux, Marcy l'Etoile, France) and the standard agar disk diffusion method (20,21). Confirmation was obtained in >96% of the tested samples, without significant differences among the 4 laboratories. Analysis of Resistance Patterns of Commensal E. coli Susceptibility to several antimicrobial agents representative of various classes (ampicillin, tetracycline, trimethoprim-sulfamethoxazole, chloramphenicol, kanamycin, gentamicin, nalidixic acid, ciprofloxacin) was tested in 1,405 (8%) E. coli isolates randomly selected from the 18,042 collected samples. Each isolate was spread onto Mueller-Hinton (MH) agar plates containing each antimicrobial agent at a concentration 20% higher than the breakpoints for resistance of each antimicrobial agent, as per National Committee of Laboratory Standards guidelines (20,21). The inoculum inoculum /in·oc·u·lum/ (-ok´u-lum) pl. inoc´ula material used in inoculation. in·oc·u·lum n. pl. size was [approximately equal to]2 x [10.sup.5] CFU CFU see colony-forming units. per spot. A plate of antimicrobial drug-free medium was always included as a growth control. E. coli ATCC ATCC American Type Culture Collection, see there 25922, and E. coli strains from our collection resistant to the various antimicrobial agents used in the assay were always included for quality control purposes. Results were recorded after incubation at 37[degrees]C for 18 hours. A resistance phenotype was assigned when growth was observed on the medium containing an antimicrobial agent. An MDR phenotype was intended as resistance to [greater than or equal to]2 classes of antimicrobial agents. Isolates from the same study participant that exhibited the same resistance phenotype (the random sampling procedure did not initially consider the study participant source) were considered replicated isolates and were counted only once for data analysis. According to this criterion, data analysis was conducted with 1,080 isolates (Figure 1). Data entry and analysis were calculated with the EpiInfo software package (version 2002, Centers for Disease Control and Prevention Centers for Disease Control and Prevention (CDC), agency of the U.S. Public Health Service since 1973, with headquarters in Atlanta; it was established in 1946 as the Communicable Disease Center. , Atlanta, GA, USA). Statistical differences in the prevalence of antimicrobial drug resistances were determined by the [chi square chi square (kī), n a nonparametric statistic used with discrete data in the form of frequency count (nominal data) or percentages or proportions that can be reduced to frequencies. ] test. Molecular Analysis of Resistance Genes and Conjugation Assay Acquired resistance genes and conjugative transfer of resistance traits were investigated in 78 isolates randomly selected from those representative of the 2 most common MDR phenotypes (Figure 1). Resistance genes [bla.sub.TEM], catI, dfrA8, sull n. 1. A plow. , and sul2 and the intI1 integrase gene were detected by colony blot hybridization hybridization /hy·brid·iza·tion/ (hi?brid-i-za´shun) 1. crossbreeding; the act or process of producing hybrids. 2. molecular hybridization 3. (22) with specific probes generated by polymerase chain reaction polymerase chain reaction (pŏl`ĭmərās') (PCR), laboratory process in which a particular DNA segment from a mixture of DNA chains is rapidly replicated, producing a large, readily analyzed sample of a piece of DNA; the process is (PCR PCR polymerase chain reaction. PCR abbr. polymerase chain reaction Polymerase chain reaction (PCR) ), as described previously (23-25). Tetracycline resistance genes tet(A), tet(B), tet(C), and tet(D) were detected by PCR, as described previously (26). Conjugative transfer of resistance genes was assayed in MH broth using E. coli J53 (auxotropic for proline proline (prō`lēn), organic compound, one of the 20 amino acids commonly found in animal proteins. Only the l-stereoisomer appears in mammalian protein. and methionine methionine (mĕthī`ənēn), organic compound, one of the 20 amino acids commonly found in animal proteins. Only the L-stereoisomer appears in mammalian protein. and resistant to rifampin rifampin (rĭfăm`pĭn), antibiotic used in the treatment of tuberculosis. It is also used to eliminate the meningococcus microorganism from carriers and to treat leprosy, or Hansen's disease. and nalidixic acid) as a recipient and an initial donor/recipient ratio of 0.1. Mating tubes were incubated at 30[degrees]C for 14 h. Transconjugants were selected on MH agar containing rifampin (400 [micro]g/mL) and nalidixic acid (32 [micro]g/mL) plus one of the following antimicrobial agents: ampicillin (200 [micro]g/mL), tetracycline (5 [micro]g/mL), chloramphenicol (30 [micro]g/ mL), or trimethoprim-sulfamethoxazole (40/200 [micro]g/mL). Under the above conditions, the detection sensitivity of the mating assay was [greater than or equal to]1 x [10.sup.8] transconjugants/recipients. Results Antimicrobial Drug-Resistance Rates Overall, high resistance rates were observed for ampicillin (95%), trimethoprim-sulfamethoxazole (94%), tetracycline (93%), streptomycin (82%), and chloramphenicol (70%). Lower resistance rates were observed for nalidixic acid (35%), kanamycin (28%), gentamicin (21%), and ciprofloxacin (18%). Resistance to ceftriaxone and amikacin was uncommon (<0.5%) (Table 1). For first-line oral antimicrobial agents such as ampicillin, tetracycline, and trimethoprim-sulfamethoxazole, resistant strains were present as the dominant flora in >80% of carriers (Table 1). Resistance rates for ampicillin, trimethoprim-sulfamethoxazole, kanamycin, and streptomycin were significantly higher in Bolivia than in Peru (p<0.001), whereas ciprofloxacin resistance rates were significantly higher in Peru than in Bolivia (p<0.001) (Table 1). Differences in the resistance rates were also observed within each country. In Bolivia, higher overall resistance rates were found in Camiri than in Villa Montes (p<0.001) for chloramphenicol, streptomycin, gentamicin, nalidixic acid, and ciprofloxacin (Table 1). In Peru, higher overall resistance rates were found in Moyobamba than in Yurimaguas. The most significant differences (p<0.001) were noted for streptomycin, nalidixic acid, and ciprofloxacin (Table 1). Significantly higher (p<0.05) resistant rates were observed in boys, with some agents, and in some settings (ampicillin in both Peruvian cities, trimethoprim-sulfamethoxazole in Moyobamba, and chloramphenicol, kanamycin, and gentamicin in Camiri). Analysis by age showed that, with all agents (ceftriaxone and amikacin were not considered in this analysis because of the low numbers of resistant isolates), resistance rates were notably higher in the youngest age group, and an overall decreasing trend by age was observed (Figure 2). With some agents (kanamycin, gentamicin, and the quinolones), the decreasing trend was essentially limited to the younger age groups; with other agents (ampicillin, tetracycline, trimethoprim-sulfamethoxazole, and chloramphenicol); this phenomenon was more evident in the older age groups. Combinations of Antimicrobial Drug-resistance Traits in Healthy Children Of the 3,174 children evaluated in the study, only 84 (2.7%) carried an E. coli fecal population susceptible to all the antimicrobial agents tested, while 46 (1.5%), 73 (2.3%), 187 (5.9%), 537 (17%), 808 (26%), 624 (20%), and 816 (26%) had an E. coli population resistant to 1, 2, 3, 4, 5, 6, or >6 antimicrobial agents. No significant differences in this distribution were observed between the 2 countries. Of the 156 different combinations of resistance observed, 2 were most prevalent: 1) the pattern with 4 resistances, (ampicillin, tetracycline, trimethoprim-sulfamethoxazole, and streptomycin) in 361 (11.5%) children and 2) the pattern with 5 resistances, (ampicillin, tetracycline, trimethoprim-sulfamethoxazole, streptomycin, and chloramphenicol) in 567 (18%) children. Patterns of Resistance Phenotypes of E. coli Isolates Frequency and patterns of resistance phenotypes were determined on a random sample of 1,080 nonreplicate resistant E. coli isolates with 8 antimicrobial agents representative of 6 different classes (ampicillin for [beta]-lactams, tetracycline for tetracyclines Tetracyclines Definition Tetracyclines are medicines that kill certain infection-causing microorganisms. Purpose Tetracyclines are called "broad-spectrum" antibiotics, because they can be used to treat a wide variety of , chloramphenicol for phenicols, trimethoprim-sulfamethoxazole for folate folate /fo·late/ (fo´lat) 1. the anionic form of folic acid. 2. more generally, any of a group of substances containing a form of pteroic acid conjugated with l-glutamic acid and having a variety of substitutions. inhibitors, kanamycin and gentamicin for aminoglycosides, and nalidixic acid and ciprofloxacin for quinolones). Only a few isolates were resistant to a single drug (9%) (Figure 3). Isolates showing resistance to 3 different drugs were the most prevalent (30%), followed by those showing resistance to 4 (22%) and 2 (20%) drugs, respectively. Seven isolates (<1%) showed resistance to all tested drugs (Figure 3). An MDR phenotype was common (90% of isolates). Resistance patterns were quite variable. Of 97 different patterns observed, some were highly prevalent. The pattern that included ampicillin, tetracycline, and trimethoprim-sulfamethoxazole was the most prevalent, followed by that including ampicillin, tetracycline, trimethoprim-sulfamethoxazole, and chloramphenicol, as well as that including ampicillin and trimethoprim-sulfamethoxazole alone (22%, 15%, and 10% of the tested isolates, respectively) (Figure 3). Acquired Resistance Genes and Transferability of Resistance Traits The prevalence of several acquired resistance genes ([bla.sub.TEM] for ampicillin resistance; tet(A)-(D) for tetracycline resistance; dfrA8 for trimethoprim trimethoprim /tri·meth·o·prim/ (-meth´o-prim) an antibacterial closely related to pyrimethamine; almost always used in combination with a sulfonamide, primarily for the treatment of urinary tract infections. resistance; sull and sul2 for sulfonamide sulfonamide /sul·fon·amide/ (sul-fon´ah-mid) a compound containing the sbondSO2NH2 group. The sulfonamides, or sulfa drugs, are derivatives of sulfanilamide, competitively inhibit folic acid synthesis in microorganisms, and formerly were resistance; catI for chloramphenicol resistance) and class 1 integrons was investigated in 78 isolates randomly selected from representatives of the 2 most prevalent MDR phenotypes (ampicillin/tetracycline/trimethoprim-sulfamethoxazole, n = 45; ampicillin/ tetracycline/trimethoprim-sulfamethoxazole/chloramphenicol, n = 33). In most cases the resistance phenotype could be accounted for by a combination of the above resistance genes, and some of them appeared to be highly prevalent (Table 2). The presence of the intI1 integrase gene (associated with class 1 integrons) was detected in 35% of MDR isolates. These 78 isolates were also tested for transferability of resistance traits in conjugation experiments. Overall, the transfer of at least 1 resistant trait was observed in 37 cases (47%). Transfer rates for each resistance trait were as follows: ampicillin 46%, tetracycline 40%, trimethoprim-sulfamethoxazole 41%, and chloramphenicol 27%. Cotransfer of all the resistance traits was observed in 26 of the 37 cases that gave positive results in the conjugation experiments. Molecular analysis of the transconjugants showed that, in all the cases, the resistance phenotype could be accounted for by the acquisition of resistance genes detected in the respective donors. Conjugative transfer of class 1 integrons was observed in 10 (37%) of the 27 intI1-positive isolates. Discussion Similar to pathogenic bacteria Pathogenic bacteria Bacteria that produce illness. Mentioned in: Gastroenteritis , commensals are exposed to the selective pressure of antimicrobial agents, and commensal E. coli have often been used as an indicator of the dissemination of acquired resistance genes (7,8,11-13,15,27). To our knowledge, this study is the first to address the status of antimicrobial drug resistance in commensal E. coli in a large population of preschool-age children from urban settings of low-resource countries. Results showed a high prevalence (70%-95%) of healthy carriers of E. coli resistant to a number of older antimicrobial agents (ampicillin, tetracycline, trimethoprim-sulfamethoxazole, chloramphenicol, and streptomycin). For these drugs, the small differences observed among localities, although sometimes statistically significant, are probably of limited clinical and epidemiologic relevance and presumably pre·sum·a·ble adj. That can be presumed or taken for granted; reasonable as a supposition: presumable causes of the disaster. attributable to the large number of antimicrobial drug-resistant E. coli carriers. A relatively high prevalence (18%-35%) of carriers of E. coli resistant to other agents (kanamycin, gentamicin, nalidixic acid, and ciprofloxacin) was also observed, while the carriage of E. coli resistant to expanded-spectrum cephalosporins Cephalosporins Definition Cephalosporins are medicines that kill bacteria or prevent their growth. Purpose Cephalosporins are used to treat infections in different parts of the body—the ears, nose, throat, lungs, sinuses, and and amikacin was uncommon (<0.5%). Ranking patterns of resistance rates were similar overall in each of the 4 studied areas, which suggests a common scenario in urban areas of these 2 Latin American countries. This view is further supported by data recently published for adults from Lima (Peru), where similar resistance rates were reported (12). Our findings were in substantial agreement with previous reports of high resistance rates in commensals of study participants from low-resource settings (7,8,11-13,15,28). Comparative analysis with previous data available for 1 studied setting (Camiri, Bolivia) surveyed 10 years earlier (7) indicated a significant increase in the resistance rates to gentamicin and nalidixic acid and the de novo [Latin, Anew.] A second time; afresh. A trial or a hearing that is ordered by an appellate court that has reviewed the record of a hearing in a lower court and sent the matter back to the original court for a new trial, as if it had not been previously heard nor decided. appearance of resistance to ciprofloxacin. One aspect that was not previously reported among preschool children was the age-related differences in resistance rates; rates were significantly higher in the younger age groups. This phenomenon could reflect a larger use of antimicrobial drugs in younger children. However, this explanation cannot be the case for quinolones, which are not prescribed in this age group. Another influencing factor could be dietary changes related to weaning weaning, n the period of transition from breast feeding to eating solid foods. weaning the act of separating the young from the dam that it has been sucking, or receiving a milk diet provided by the dam or from artificial sources. . In fact, a diet high in milk that contains abundant lactoferrin lactoferrin (lak´tōfer´in), n an iron-binding protein found in the specific granules of neutrophils where it apparently exerts an antimicrobial activity by withholding iron from ingested bacteria and fungi. , which chelates dietary iron, has been hypothesized to favor the presence of strains expressing iron-uptake systems (such as aerobactin or enterobactin), which are often encoded by plasmids that also carry resistance genes (29). However, further investigation will be necessary to clarify the mechanism responsible for this phenomenon. Multiple resistance traits in the commensal E. coli microbiota were apparently the rule, as they were detected in most study participants. The simultaneous presence of multiple strains expressing different resistance phenotypes and single strains expressing MDR phenotypes could contribute to this phenomenon. Although the relative contribution of the 2 mechanisms was not specifically investigated, the high prevalence of strains expressing MDR phenotypes probably provides a major contribution. Some MDR patterns (e.g., ampicillin/tetracycline/trimethoprim-sulfamethoxazole, ampicillin/tetracycline/ trimethoprim-sulfamethoxazole/chloramphenicol) were common and could be accounted for by a number of known acquired resistance genes. Resistance traits could be transferred by conjugation, often en bloc, suggesting a linkage of the corresponding resistance genes in self-transferable or mobilizable plasmids. In conclusion, this study underscores the magnitude of the problem of antimicrobial drug resistance in low-resource settings and the urgent need for surveillance and control of this phenomenon. Inexpensive, sensitive, and simple methods to monitor antimicrobial drug resistance in commensal bacteria could be valuable tools for large-scale surveillance studies and to improve the efficacy of resistance control interventions. The direct plating method used in this study, which had previously shown high sensitivity and specificity in detecting resistant E. coli (19), was confirmed to be a valid tool to conduct such a large-scale survey. Acknowledgments We thank other members of the ANTRES Study Group for their support in this study: Ruth Arias, Vieri Boddi, Paolo Bonanni, Mirtha Camacho, Blanca Huapaya, Charlotte Kristiansson, Oscar Lanza Van den Berghe, Mattias Larsson, Luis Pacheco, Angela Pieri, Victor Suarez, Esteban Salazar, and Christian Trigoso. We are also grateful to the local health authorities for cooperation in carrying out the study, the laboratory staff for technical assistance, the field team members for valuable support in collecting samples, and all participating children and their parents for their willingness to take part to the survey. The study was carried out within the research activities of the ANTRES project, supported by the European Commission, INCO-DEV programme, contract no. ICA Ica (ē`kä), city (1993 pop. 108,724), capital of Ica dept., SW Peru, on the Pan-American Highway. It is a commercial center for the cotton, wool, and wine produced in the region. There are several summer resorts nearby. 4-CT-2001-10014. Dr Bartoloni is associate professor of infectious diseases at the University of Florence History The University of Florence evolved from the Studium Generale, which was established by the Florentine Republic in 1321. The Studium was recognized by Pope Clement VI in 1349, and authorised to grant regular degrees. , Italy. His research interests include antimicrobial drug resistance and tropical medicine tropical medicine, study, diagnosis, treatment, and prevention of certain diseases prevalent in the tropics. The warmth and humidity of the tropics and the often unsanitary conditions under which so many people in those areas live contribute to the development and . References (1.) Byarugaba DK. A view on antimicrobial resistance in developing countries and responsible risk factors. Int J Antimicrob Agents. 2004;24:105-10. (2.) World Health Organization. WHO report on infectious diseases 2000. Overcoming antimicrobial resistance. Geneva Geneva, canton and city, Switzerland Geneva (jənē`və), Fr. Genève, canton (1990 pop. 373,019), 109 sq mi (282 sq km), SW Switzerland, surrounding the southwest tip of the Lake of Geneva. : The Organization; 2000. (3.) World Health Organization. Global strategy for containment of antimicrobial resistance. Geneva: The Organization; 2001 [cited 2006 Jan 27]. Available from http://www.who.int/dmgresistance/en/ (4.) Okeke IN, Lamikanra A, Edelman R. Socio-economic and behavioral factors leading to acquired bacterial resistance to antimicrobrial agents in developing countries. Emerg Infect Dis. 1999;5:18-27. (5.) Shears R Antibiotic resistance antibiotic resistance, n the ability of certain strains of microorganisms to develop resistance to antibiotics. antibiotic resistance in the tropics tropics, also called tropical zone or torrid zone, all the land and water of the earth situated between the Tropic of Cancer at lat. 23 1-2°N and the Tropic of Capricorn at lat. 23 1-2°S. . Epidemiology and surveillance of antimicrobial resistance in the tropics. Trans R Soc Trop Med Hyg. 2001 ;95:127-30. (6.) Bartoloni A, Colao MG, Roselli M, Orsi A, Aquilini D, Corti G, et al. Antimicrobial agent susceptibility patterns of staphylococci staph·y·lo·coc·cus n. pl. staph·y·lo·coc·ci A spherical gram-positive parasitic bacterium of the genus Staphylococcus, usually occurring in grapelike clusters and causing boils, septicemia, and other infections. isolated in urban and rural areas of Bolivia. J Trop Med Hyg. 1990;93:360-4. (7.) Bartoloni A, Cutts F, Leoni S, Austin CC, Mantella A, Guglielmetti P, et al. Patterns of antimicrobial use and antimicrobial resistance among healthy children in Bolivia. Trop Med Int Health. 1998;3:116-23. (8.) Bartoloni A, Bartalesi F, Mantella A, Dell'Amico E, Roselli M, Strohmeyer M, et al. High prevalence of acquired antimicrobial resistance unrelated to heavy antimicrobial consumption. J Infect Dis. 2004; 189:1291-4. (9.) Walson JL, Marshall B, Pokhrel BM, Katie KK, Levy SB. Carriage of antibiotic-resistant fecal bacteria in Nepal reflects proximity to Kathmandu. J Infect Dis. 2001;184:1163-9. (10.) Calva JJ, Sifuentes-Osornio J, Cer6n C. Antimicrobial resistance in faecal fae·cal adj. Chiefly British Variant of fecal. Adj. 1. faecal - of or relating to feces; "fecal matter" fecal flora: longitudinal community-based surveillance of children from urban Mexico. Antimicrob Agents Chemother. 1996;40: 1699-702. (11.) Lester SC, del Pilar Pilar strong-minded female leader of a group of guerrillas in the Spanish Civil War. [Am. Lit.: Hemingway For Whom the Bell Tolls] See : Female Power Pilar Pla M, Wang F, Pere père n. 1. Used after a man's surname to distinguish a father from a son: Dumas père primarily wrote novels, while dramas occupied Dumas fils. 2. Schael I, Jiang H, O'Brien TF. The carriage of Escherichia coli resistant to antibiotic agents by healthy children in Boston, in Caracas, Venezuela and in Qin Pu, China. N Engl J Med. 1990;323:285-9. (12.) Nys S, Okeke IN, Kariuki S, Dinant GJ, Driessen C, Stobberingh EE. Antibiotic resistance of faecal Escherichia coli from healthy volunteers from eight developing countries. J Antimicrob Chemother. 2004;54:952-5. (13.) Okeke IN, Fayinka ST, Lamikanra A. Antibiotic resistance in Escherichia coli from Nigerian students, 1986-1998. Emerg Infect Dis. 2000;6:393-6. (14.) Shanahan PM, Wylie BA, Adrian PV, Koomhof HJ, Thomson CJ, Amyes GB. The prevalence of antimicrobial resistance in human faecal flora in South Africa. Epidemiol Infect. 1993;111:221-8. (15.) van de Mortel HJ, Jansen EJ, Dinant G J, London N, Palacios Pru E, Stobberingh EE. The prevalence of antibiotic-resistant faecal Escherichia coli in healthy volunteers in Venezuela. Infection. 1998;26:292-7. (16.) Col NF, O'Connor RW. Estimating worldwide current antibiotic usage: report of Task Force 1. Rev Infect Dis. 1987;9(Suppl 3)3:232-43. (17.) O'Brien TF. Global surveillance of antibiotic resistance. N Engl J Med. 1992;326:339-40. (18.) World Health Organization. Management and prevention of diarrhoea: practical guidelines. 3rd ed. Geneva: The Organization; 1993. (19.) Bartoloni A, Benedetti M, Pallecchi L, Larsson M, Mantella A, Strohmeyer M, et al. Evaluation of a rapid screening method for detection of antimicrobial resistance in the commensal microbiota of the gut. Trans R Soc Trop Med Hyg. 2006;100:119-25. (20.) National Committee for Clinical Laboratory Standards. Methods for dilution antimicrobial susceptibility tests for bacteria that grow aerobically. 6th ed. Approved standard M07-A6. Wayne (PA): The Committee; 2003. (21.) National Committee for Clinical Laboratory Standards. Performance standards for antimicrobial susceptibility testing. 13th informational supplement M100-S13. Wayne (PA); The Committee; 2004. (22.) Sambrook J, Russel DW. Molecular cloning: a laboratory manual, 3rd ed. Cold Spring Harbor (NY): Cold Spring Harbor Laboratory  The Cold Spring Harbor Laboratory Press; 2001.(23.) Maynard C, Bekal S, Sanschagrin F, Levesque RC, Brousseau R, Masson L, et al. Heterogeneity among virulence and antimicrobial resistance gene profiles of extraintestinal Escherichia coli isolates of animal and human origin. J Clin Microbiol. 2004;42:5444-52. (24.) Lee JC, Oh JY, Cho JW, Park JC, Kim JM, Seol SY, et al. The prevalence of trimethoprim-resistance-conferring dihydrofolate reductase dihydrofolate reductase enzyme catalyzing the conversion of folate to 5,6,7,8-tetrahydrofolate, which is the key carrier of one-carbon units in purine and pyridime synthesis, the pathway for the breakdown of histidine and the synthesis of S-adenosylmethionine from S genes in urinary isolates of Escherichia coli in Korea. J Antimicrob Chemother. 2001;47:599-604. (25.) Infante in·fan·te n. A son of a Spanish or Portuguese king other than the heir to the throne. [Spanish and Portuguese, both from Latin B, Grape M, Larsson M, Kristiansson C, Pallecchi L, Rossolini GM, et al. Acquired sulfaonamide resistance genes in faecal Escherichia coli from healthy children in Bolivia and Peru. Int J AntimicrobAgents. 2005;25:308 12. (26.) Hartman AB, Essiet II, Isenbarger DW, Lindler LE. Epidemiology of tetracycline resistance determinants in Shigella shigella Any of the rod-shaped bacteria that make up the genus Shigella, which are normal inhabitants of the human intestinal tract and can cause dysentery, or shigellosis. Shigellae are gram-negative (see gram stain), non-spore-forming, stationary bacteria. S. spp. and enteroinvasive Escherichia coli: characterization and dissemination of tet(A)-1. J Clin Microbiol. 2003;41:1023-32. (27.) Alliance for Prudent Use of Antibiotics (APUA APUA Alliance for the Prudent Use of Antibiotics APUA Antigua Public Utilities Authority ). Reservoirs of Antibiotic Resistance Network (ROAR). Commensal bacteria are reservoirs of resistance. 2004 [cited 2006 Jan 27]. Available from http://www.tufts.edu/med/apua/ROAR/project.htm (28.) Grenet K, Guillemot guillemot (gĭl`əmŏt'), northern sea bird, genus Cephas, of the auk family. The black guillemot, or trystie, Cephus grylle, is about 13 in. D, Jarlier V, Moreau B, Dubourdieu S, Ruimy R, et al. Antibacterial antibacterial /an·ti·bac·te·ri·al/ (-bak-ter´e-al) destroying or suppressing growth or reproduction of bacteria; also, an agent that does this. an·ti·bac·te·ri·al adj. resistance, Wayampis amerindians, French Guyana. Emerg Infect Dis. 2004; 10:1150-3. (29.) Khachatryan AR , Hancock DD, Besser TE, Call DR. Role of calf-adapted Escherichia coli in maintenance of antimicrobial drug resistance in dairy calves. Appl Environ Microbiol. 2004;70:752-7. Address for correspondence: Alessandro Bartoloni, Critica Medico Chirurgica, Dipartimento Area Clinica Malattie Infettive, Universita di Firenze, Ospedale di Careggi, Viale Morgagni 85, 1-50134, Florence, Italy; email: bartoloni@unifi.it All material published in Emerging Infectious Diseases is in the public domain and may be used and reprinted without special permission; proper citation, however, is required. Alessandro Bartoloni, * Lucia Pallecchi, ([dagger]) Marta Benedetti, * Connie Fernandez, ([double dagger]) Yolanda Vallejos, ([section]) Elisa Guzman, ([paragraph]) Ana Liz Villagran, ([section]) Antonia Mantella, * Chiara Lucchetti, ([dagger]) Filippo Bartalesi, * Marianne Strohmeyer, * Angela Bechini, * Herlan Gamboa, ([section]) Hugo Rodriguez, ([double dagger]) Torkel Falkenberg, (#) Goran Kronvall, (#) Eduardo Gotuzzo, ** Franco Paradisi, * and Gian Maria Rossolini ([dagger]) * Universita di Firenze, Florence, Italy; ([dagger]) Universita di Siena, Siena, Italy; ([double dagger]) Hospital Apoyo Yurimaguas, Yurimaguas-Loreto, Peru; ([section]) Servicio Departamental de Salud Santa Cruz, Camiri, Bolivia; ([paragraph]) Hospital Moyobamba, Moyobamba-San Martin, Peru; (#) Karolinska Institute, Stockholm, Sweden; and ** Universidad Peruana Cayetano Heredia, Lima, Peru
Table 1. Prevalence, expressed as percentage, of healthy children
carrying antimicrobial drug-resistant Escherichia coli as part of their
commensal flora and of children in whom resistant E. coli constituted
the predominant flora * ([dagger])
Bolivia
Villa
Drug Camiri Montes p value
Ampicillin 98 (95) 96 (87) <0.05
SXT ([double dagger]) 98 (94) 95 (86) <0.05
Tetracycline 96 (91) 92 (82) <0.05
Streptomycin 96 (89) 88 (79) <0.001
Chloramphenicol 74 (58) 65 (40) <0.001
Nalidixic acid 44 (25) 29 (13) <0.001
Kanamycin 37 (20) 31 (12) <0.05
Gentamicin 28 (16) 18 (10) <0.001
Ciprofloxacin 21 (10) 10 (4) <0.001
Amikacin 0 0.1 (0) NA
Ceftriaxone 0.1 (0) 0.1 (0.1) NA
Peru
Drug Yurimaguas Moyobamba p value
Ampicillin 92 (76) 93 (83) NS
SXT ([double dagger]) 89 (72) 93 (83) <0.05
Tetracycline 89 (71) 93 (81) <0.05
Streptomycin 71 (50) 86 (66) <0.001
Chloramphenicol 69 (42) 72 (48) NS
Nalidixic acid 27 (8) 41 (18) <0.001
Kanamycin 22 (8) 23 (9) NS
Gentamicin 19 (9) 21 (10) NS
Ciprofloxacin 16 (5) 25 (9) <0.001
Amikacin 1 (0.4) 0.4 (0.3) NA
Ceftriaxone 0.3 (0) 0.1 (0.1) NA
Bolivia, Peru,
Drug subtotal subtotal Total p value
Ampicillin 97 (91) 92 (80) 95 (85) <0.001
SXT ([double dagger]) 96 (90) 91 (77) 94 (84) <0.001
Tetracycline 94 (86) 91 (76) 93 (81) <0.05
Streptomycin 92 (84) 79 (58) 82 (68) <0.001
Chloramphenicol 70 (49) 71 (45) 70 (47) NS
Nalidixic acid 36 (19) 38 (13) 35 (16) NS
Kanamycin 34 (16) 22 (9) 28 (12) <0.001
Gentamicin 23 (13) 20 (10) 21 (11) <0.05
Ciprofloxacin 16 (7) 21 (7) 18 (7) <0.001
Amikacin 0.1 (0.1) 1 (0.3) 0.4 (0.2) NA
Ceftriaxone 0.1 (0.1) 0.1 (0.1) 0.1 (0.1) NA
* Inside parentheses: proportion of carriers in whom resistant E. coli
constituted the predominant flora. NS, not significant; NA, not
applicable.
([dagger]) Number of children from whom samples were obtained: Camiri =
794; Villa Montes = 790; Yurimaguas = 797; Moyobamba = 793; Bolivia =
1,584; Peru = 1,590; and total= 3,174.
([double dagger]) SXT, trimethoprim-sulfamethoxazole.
Table 2. Acquired resistance genes in 78 MDR commensal
Escherichia coli *
No. No. (%) ([dagger])
resistant positive
Resistance trait isolates Resistance gene isolates
Ampicillin 78 [bla.sub.TEM] 77 (99)
Tetracycline 78 tet(A) 27 (35)
tet(B) 44 (56)
tet(D) 4 (5)
tet(A) and tet(B) 1 (1)
Trimethoprim 78 dfrA8 42 (54)
5ulfamethoxazole 78 sul1 7 (9)
sul2 54 (69)
sul1 and sul2 17 (22)
Chloramphenicol 33 catl 33 (100)
* MDR, multidrug resistant.
([dagger]) Percentages refer to positive isolates among isolates
resistant to each antimicrobial agent.
|
|
||||||||||||||||||||
Bahamas 
Printer friendly
Cite/link
Email
Feedback
Reader Opinion