Printer Friendly

La deteccion de Bartonella spp. y Rickettsia spp. en pulgas, garrapatas y piojos recolectados en las zonas rurales de Peru.

Detection of Bartonella spp. and Rickettsia spp. in fleas, ticks and lice collected in rural areas of Peru


Human bartonellosis is caused by various species of Bartonella. Nowadays, there are several species of this genus that can infect humans including B. bacilliformis, B. henselae, B. quintana, B. rochalimae, B. elizabethae, B. vinsonii subsp. arupensis, B. vinsonii subsp. berkhoffii, B. grahamii, B. koehlerae, B. washoensis, B. alsatica, and B. tamiae (Billeter et al. 2008, Daly et al. 1993, Kerkhoff et al. 1999, Roux et al. 2000, Eremeeva et al. 2007, Kosoy et al. 2008). Only B. bacilliformis, B. vinsonii, B. quintana, B. rochalimae, B. elizabethae and B. cladrrigeiae have been reported in Peru (Billeter et al. 2008, Eremeeva et al. 2007, Parola et al. 2002, Roux & Raoult 1999, Raoult et al. 1999). Bartonella is believed to be transmitted by an arthropod vector, and infection can result in Carrion's disease, cat scratch disease, trench fever, endocarditis, neuroretinitis, bacillar angiomatosis, hepatic granulomatosis, arthritis, osteomelitis, and sepsis (Bil leter et al. 2008, Breitschwerdt & Kordick 2000).

Rickettsia spp. are gram negative coco-bacilli and intracellular pathogens and most of them are transmitted transtadially by a wide variety of arthropod hosts including fleas, lice and ticks. Infections with these pathogens can cause diverse human diseases such as endemic typhus, scrub typhus, erhlichiosis and others rickettsiosis (Raoult & Roux 1997). In Peru, rickettsiosis occurs sporadically along the coast, highlands and jungle. The exposure to rickettsiosis was confirmed by immunofluorescence assay (IFA) in regions of Peru (Raoult et al. 1999, Blair et al. 2004a) and Rickettsia species were detected in ticks and fleas (Schoeler et al. 2005, Jiang et al. 2005).

Several arthropods belonging to the orders Diptera (Noguchi et al. 1929, Caceres et al., 1997), Anoplura (Ellis et al. 1999), Siphonaptera (Brouqui et al. 1999; Higgins et al. 1996) and Parasitiformes (Schouls et al. 1999, Angelakis et al. 2010) have been implicated in the transmission of Bartonella spp. Previous experimental studies have demonstrated that Lutzomyia verrucarum (sandfly) are competent vectors of B. bacilliformis, which causes Carrion's disease (Breitschwerdt & Kordick 2000, Maguina et al. 2009). In order to detect Bartonella spp. and Rickettsia spp. in fleas, lice and ticks, specimens were captured from humans, domestic and wild animals in five distinct locations in Peru, where Carrion's disease is endemic. The presence of Bartonella spp. in these specimens was evaluated by polymerase chain reaction (PCR) and confirmed by DNA sequencing.


Materials and methods

Study sites and specimen collections. Samples were collected from random houses in different places: San Ignacio (Marizagua) of Cajamarca departament; Cajaruro, Jamalca, Lonya Grande and El Milagro of Amazonas departament in July 2000 to September 2001 (Table 1, Fig. 1).

These samples were obtained from different pets such as dogs, cats, and guinea pigs (considered as a food source); moreover, foxes found near the neighborhood were trapped in cages for later sample collection. Specimens such as fleas were collected by hand from animals; but lice were collected from people (head, body and clothes) and ticks were collected only from dogs. These were then stored in vials containing 70% ethanol, and organized according to host and place of collection.

The taxonomic classification was done in the Entomology Laboratory at the "Daniel A. Carrion" Tropical Medicine Institute, of the Universidad Nacional Mayor de San Marcos in Lima, using entomological keys (Jonson 1957, Lewis 1972).

After taxonomic classification, the specimens were grouped into pools of 6 to 20 specimens, each pool from one or two hosts, to reduce the processes for analysis (see Table 1).

DNA extractions from specimens. The whole specimens were grouped in pools and washed with 1X Phosphate Buffered Saline (PBS). They were then triturated with a micro-pestle in 100 uL of PBS. DNA was extracted using a Tissue DNA Purification Kit (QIAGEN) following the standard procedure recommended by the manufacturer.

DNA amplification of the gltA gene by PCR. The gltA gene of Bartonella was amplified using the BhCS.781p and BhCS.1137 primers (Norman et al. 1995). The same specimens were analyzed using the Rp877p and Rp1258n primers, theses primers amplified the gltA gene of Ricketsia (Regnery et al. 1991).

The amplification reactions consisted of 5 [micro]L of amplification buffer 10X, 5 [micro]L (10 [micro]M) of each primer, 5 [micro]L (25 mM) of magnesium chloride, 2 [micro]L (10 mM) of nucleotide triphosphates, 0.2 [micro]L (5 U[micro]L) of AmpliTaq Gold DNA polymerase (Applied Biosystems Inc.) and 5 [micro]L of purified DNA to each tube. The final volume of the amplification reaction was 50 [micro]L. Purified DNA from B. bacilliformis strain ATCC 35685 and a Rickettsia felis characterized culture were used as positive controls. The amplifications were performed on a 9700 Applied Biosystems thermocycler, and the cycles were as follows: 1 cycle for 95 [degrees]C for 10 min; 35 cycles at 95 [degrees]C for 0.5 min, 50 [degrees]C for 0.5 min, and 72 [degrees]C for 1 min; 1 cycle at 72 [degrees]C for 5 min; and a final soaking at 4 [degrees]C until analysis.

The amplified products were analyzed by electrophoresis in agarose gels, stained with ethidium bromide and visualized in a UV transilluminator.

The amplified products were then purified using QIAQuick Gel extraction Kit (QIAGEN Inc.) and sequenced using a Big Dye DNA terminator Kit (Applied Biosystems Inc.) on an ABI310 sequencer (Applied Biosystems) at the Peruvian National Institute of Health and following standard procedures. The sequences obtained were analyzed with GenBank using BLAST software ( Clustalw software ( was used for alignment and comparison of sequences.


A total of 1758 specimens were captured from humans, cats, dogs, guinea pigs and foxes (Table 1). Of these, 1399 (79.58 %) samples were identified as Ctenocephalides felis (collected from dogs, cats, guinea pigs and foxes). 235 (13.37%) specimens were Pulex irritans (collected from dogs, guinea pigs and foxes); 84 specimens (4.78%) were Pediculus humanus (collected from humans); 34 specimens (1.93%) were Ctenocephalides canis (collected from cats); 5 specimens (0.28%) were Rhiphicephalus sanguineus (collected from dogs); and 1 specimen (0.06%) was identified as Boophilus spp. (collected from a dog) (Table 1).

One hundred two pools were processed by PCR. Of these, 17 pools (16.67%) were PCR-positive using primers for Bartonella genera. These pools were confirmed as Bartonella by DNA sequencing.

Bartonella clarridgeiae (accession number AY836149) was detected in 4 pools of C. felis collected from three cats and one guinea pig, 1 pool of C. canis collected from a cat and 2 pools of P. irritans collected from a fox (all 100% homologous with each other). The AY836149 nucleotide sequence was compared with GenBank Database showing 100% homology with B. clarridgeiae Houston-2 cat strain (U84386) (Table 2).

Bartonella rochalimae was detected in 1 pool of C. felis collected from a cat and 2 pools of P. irritans collected from guinea pigs (all 100% homologous to GenBank accession number GU583842). The GU583842 nucleotide sequence was 100% homologous with human isolated B. rochalimae BMGH strain (DQ683195) (Table 2).

Bartonella henselae was detected in 1 pool of C. felis collected from a cat and 1 of P. humanus collected from humans (accession numbers AY840994 and GU583844). Both AY840994 and GU583844 nucleotide sequences showed 100% homology with B. henselae strains: BR01 (GU056191), BCF01 (GU056188) and CS3 (FJ832097) (Table 2).

Bartonella spp. was detected in 5 pools of P. irritans: four pools collected from guinea pig and one from a dog, all 100% homologous to GenBank accession No GU583846. The GU583846 nucleotide sequence showed 96.3% and 96.6% homology with Bartonella spp. DNA detected in a flea and blood collected from Sigmodon hispidus with GenBank accession numbers EF616666 and AF082322, respectively (Table 2).

Seventy-six pools (74.51%) were PCR positive using primers for Rickettsia. Of these, 66 pools were positive for Rickettsia felis (58 pools of C. felis, 2 pools of C. canis and 6 pools of P. irritans; all 100% homologous to GenBank no. GU583847). The GU583847 nucleotide sequence showed 100% homology with Rickettsiafelis collected from C. felis (EU853837), Liposcelis bostrychophila (GQ329877, GQ329873), and Pulex echidnopha goides (GU447233) (Table 3).

Ten pools were positive for Rickettsia spp. (4 pools of C. felis, 4 pools of P. irritans and 2 pools of P. humanus), where one of the pools was reported as GenBank no. GU583848 and the other nine pools were 100% homologous to GU583849 (Table 3). The nucleotide sequence GU583848 showed 100% homology with Rickettsia spp. collected from Pulex irritans (EU853838), Echidnophaga gallinacea (DQ166938), C. canis (AF516333) and C. felis (AY953289); also the nucleotide sequence GU583849 showed 100% homology with Rickettsia sp. collected from C. felis (AY953288) and C. canis (AF516331). DNA of Bartonella and Rickettsia weren't detected in ticks.


In this study, only 17 pools were confirmed as Bartonella species by DNA sequencing: Bartonella clarridgeiae (7 pools), B. rochalimae (3 pools), B. henselae (2 pools), and uncultured Bartonella spp. (5 pools).

Bartonella DNA was also detected in fleas in other regions of Peru. Parola and colleagues (Parola et al. 2002) reported the detection of B. clarridgeiae-like (potentially B. rochalimae) DNA (Eremeeva et al. 2007) and B. vinsonii DNA in fleas near the city of Cuzco. In addition, Raoult and collaborators (Raoult et al. 1997) also reported the detection of B. quintana DNA in lice collected in Calca, Cuzco.

In this study, a potentially new species of Bartonella in Pulex irritans collected from guinea pigs was found. The nucleotide sequence of Bartonella sp. showed 96% homology with Bartonella sp. DNA, which was detected in a flea and blood collected from Sigmodon hispidus (Abbot et al. 2007).

There are also previous reports of Rickettsia spp. in Peru. In the region of Sapillica, Piura; Rickettsia felis was detected in C. felis (2 pools of 59 samples) from dogs and the Rickettsia massilae group was detected in Amblyomma maculatum (one tick from a dog and one from a horse), Anocenter nitens (one tick from a horse) and Ixodes boliviensis (one tick from a horse) (Blair et al. 2004b). Also in this area, Rickettsia of the spotted fever group (SFG) was detected in four febrile patients by PCR analysis; the detected SFG in this study was approximately 95% homologous with R. conorii and R. akari (Blair et al. 2004b). Other reports indicated the presence of anti-Rickettsia antibodies in habitants of Piura, Junin and Cusco (Schoeler et al. 2005). Although a higher proportion of positive pools for R. felis (66 positive pools out of 102) were obtained, previous reports are congruent with the results found. In addition, we detected Rickettsia sp in Peru, which are 100% homologous with Rickettsia spp. detected in fleas from other countries. Also this sequence showed 95% homology with candidatus R. andeanea reported in fleas collected from Sullana in northwestern Peru (Blair et al. 2004a).

In conclusion, the results indicate the presence of several Bartonella species, and Rickettsia in Peru. The clinical and epidemiological significance of possible infections in similar endemic areas in Peru should continue to be investigated and these results should be considered for the epidemiologic and entomologic surveillance. Furthermore, the possible transmission to humans should also be evaluated in the future.


This work is dedicated in memory of Dr. Hugo Vizcarra Franco, principal professor of Medicine Faculty of Universidad Nacional Mayor de San Marcos, he was member of our research team and died during project development. We thank villagers from Marizagua, El Ron, Aserradero, Jamalca, El Valor, Yungasuyo, Pucallpa and Danja for permit the sampling in his animals. We specially thank Dr. Michael Kosoy and Sara Billeter from CDC, Colorado USA; and Dr. Audrey Lenhart from Liverpool Scholl of Tropical Medicine of England for critically reading the manuscript. This work was supported by a grant from the Fundacion Hipolito Unanue of Lima, Peru.

Literature cited

Abbot P., A.E. Aviles, L. Eller, L.A. Durden. 2007. Mixed infections, cryptic diversity, and vector-borne pathogens: evidence from Polygenis fleas and Bartonella species. Appl Environ Microbiol 73(19):6045-52.

Angelakis E., S.A. Billeter, E.B. Breitschwerd, E.B., B.B. Chomel and D. Roult. 2010. Potencial for tick-Borne Bartonellosis. Emerging Infectious Diseases 16: 385-391.

Billeter S.A., M.G. Levy, B.B. Chomel & E.B. Breitschwerdt. 2008. Vector transmission of Bartonella species with emphasis on the potential for tick transmission. Medical and Veterinary Entomology 22, 1-15.

Blair P., J.U Jiang, G.B. Schoeler, C. Moron, E. Anaya, M. Cespedes, et al. 2004a Characterization of spotted fever group rickettsiae in flea and tick specimens from Northern Peru. Journal of Clinical Microbiology 42, 4961-4967.

Blair P.J., G.B Schoeler, C. Moron, E. Anaya, R. Caceda, M. Cespedes, et al. 2004b Evidence of rickettsial and Leptospira infections in Andean northern Peru. American Journal of Tropical Medicine and Hygiene 70, 357-363.

Breitschwerdt E.B. & D.L. Kordick. (2000) Bartonella infection in animals: carriership, reservoir potential, pathogenicity and zoonotic potential for human infection. Clinical Microbiology Review 13, 428-438.

Brouqui P., B. Lascola, V. Roux, & D. Raoult. 1999. Chronic Bartonella quintana bacteremia in homeless patients. The New England Journal of Medicine 340,184-189.

Caceres A.G., E.A. Galati, F. Le Pont, C. Velasquez. 1997. Possible role of Lutzomyia maranonensis and Lu. robusta (Diptera: Psychodidae) as vectors of human bartonellosis in three provinces of Region Nor Oriental del Maranon--Peru. Revista do Instituto de Medicina Tropical de Sao Paulo 39, 51-52.

Daly J.S., M.G. Worthington, D.J. Brenner, C.W. Moss, D.G. Hollis, R.S. Weyant, et al. 1993. Rochalimaea elizabethae sp. nov., isolated from a patient with endocarditis. Journal of Clinical Microbiology 31, 872-881.

Ellis B.A., L.D. Rotz, J.A.D. Leake, F. Samalvides, J. Bernable, G. Ventura, et al. 1999. An outbreak of acute bartonellosis (Oroya fever) in the Urubamba region of Peru 1998. The American Journal of Tropical Medicine and Higiene 61, 344-349.

Eremeeva M.E., H.L. Gerns, S.L. Lydy, J.S Goo, R.T. Ryan, S.S. Mathew, et al. 2007. Bacteremia, fever and splenomegaly caused by a newly recognized Bartonella species. New England Journal of Medicine 356, 2381-2387.

Higgins J.A., S. Radulovic, D.C. Jaworski & A.F. Azad. 1996. Acquisition of the cat scratch disease agent Bartonella henselae by cat fleas (Siphonaptera: Pulicidae). Journal of Medical Entomology 33, 490-495.

Jiang J., P.J. Blair, V. Felices, C. Moron, M. Cespedes, E. Anaya, et al. 2005. Phylogenetic analysis of a novel molecular isolate of spotted fever group Rickettsiae from northern Peru: Candidatus Rickettsia andeanae. Annals of the New York Academy of Sciences 1063, 337-342.

Jonson P.T. 1957. A classification of the Siphonaptera of South America, with descriptions of New Species. Memmorial Entomological Society of Washington 5, 1-128.

Kerkhoff F.T., A.M. Bergmans, A. van Der Zee & A. Rothova. 1999. Demonstration of Bartonella grahamii DNA in ocular fluids of a patient with neuroretinitis. Journal of Clinical Microbiology 37, 4034-4038.

Kosoy, M., C. Morway, K.W. Sheff, Y. Bai, J. Colborn, L. Chalcraft, et al. 2008. Bartonella tamiae sp. nov., a newly recognized pathogen isolated from three human patients from Thailand. Journal of Clinical Microbiology, 46,772-775.

Lewis R.E. 1972. Notes on the geographical distribution and host preferences in the order Siphonaptera. Journal of Medical Entomology 9, 511-520.

Maguina C, H. Guerra & P. Ventosilla.2009. Bartonellosis. Clinics in Dermatology 27(3):271-80

Noguchi H., R.C. Shannon, E.B. Tilden, & J.R. Tyler. 1929. Etiology of Oroya fever. XIV. The insect vectors of Carrion's disease. Journal of Experimental Medicine, 49, 993-1008.

Norman A.F., R. Regnery, P. Jameson, C. Greene, & D.C. Krause. 1995. Differentiation of Bartonella-like isolates at the species level by PCR-restriction fragment length polymorphism in the citrate synthase gene. Journal of Clinical Microbiology 33, 1797-1803.

Parola P., O.Y. Sanogo, K. Lerdthusnee, Z. Zeaiter, G. Chauvancy, J.P. Gonzalez, et al. 2003. Identification of Rickettsia spp. and Bartonella spp. in fleas from the Thai-Myanmar Border. Annals of the New York Academy of Sciences 990,173-81.

Parola P., S. Shpynov, M. Montoya, M. Lopez, P. Houpikian, Z. Zeaiter, et al. 2002. First molecular evidence of new Bartonella spp. in fleas and tick from Peru. Am Journal of Tropical Medicine and Hygiene 67,135-136.

Raoult, D. & V. Roux. 1997. Rickettsioses as paradigms of new or emerging infectious diseases. Clinical Microbiology Review, 10, 694-719.

Raoult, D., R.J. Birtles, M. Montoya, E. Perez, H. Tissot-Dupont, V. Roux, & Guerra, H. 1999. Survey of three bacterial louse-associated diseases among rural Andean communities in Peru: prevalence of epidemic typhus, trench, and relapsing fever. Clinical Infectious Diseases, 29, 434-436.

Regnery R.L., C.L. Spruill, & B.D. Plikaytis. 1991. Genotypic identification of rickettsiae and estimation of intraspecies sequence divergence for portions of two rickettsial genes. Journal of Bacteriology 1991, 173:1576-89.

Roux, V. & D. Raoult. 1999. Body lice as tools for diagnosis and surveillance of reemerging diseases. Journal of Clinical Microbiology 37, 596-599.

Roux, V.S., S.J. Eykyn, S. Wyllie, & D. Raoult. 2000. Bartonella vinsonii subsp. berkhoffii as an agent of afebrile blood culture-negative endocarditis in a human. Journal of Clinical Microbiology, 38, 1698-1700.

Schoeler G., C. Moron, A. Richards, P. Blair, & J. Olson. 2005. Human spotted fever rickettsial infections. Emerging Infectiuos Diseases, 11, 622-624.

Schouls, L.M., I. Van de Pol, S.G. Rijpkema, & C. S. Schot. 1999. Detection and identification of Ehrlichia, Borrelia burgdorferi sensu lato, and Bartonella species in dutch Ixodes ricinus ticks. Journal of Clinical Microbiology 37, 2215-2222.

Abraham G. Caceres (1, 2), Carlos P. Padilla Rojas (3), Javier Arias Stella (4), Gerardo Huatuco Crisanto (5), Antero Gonzales Perez (6)

(1) Departamento de Microbiologia Medica, Facultad de Medicina Humana, Universidad Nacional Mayor de San Marcos, Lima--Peru.

Autor para correspondencia E-mail Abraham G. Caceres:

(2) Laboratorio de Entomologia, Instituto Nacional de Salud, Lima--Peru

(3) Laboratorio de Biotecnologia y Biologia Molecular, Instituto Nacional de Salud, Lima--Peru

(4) Instituto de Patologia y Biologia Molecular Arias Stella, Lima--Peru

(5) Centro de Salud de San Ignacio, Sub Region de Salud Jaen, Direccion Regional de Salud Cajamarca, Cajamarca--Peru

(6) Hospital de Apoyo Santiago Apostol Utcubamba, Red de Salud Unidad Ejecutora 404 Utcubamba, Direccion

Presentado: 15/04/2013

Aceptado: 15/09/2013

Publicado online: 09/12/2013
Table 1. Arthropods collected from cats, dogs, guinea pigs,
foxes and humans from San Ignacio (Cajamarca) and Utcubamba
(Amazonas) in Peru.

District         Host (Number)             Species

                cat (10)          Ctenocephalides felis
Cajamarca/      cat (2)           Ctenocephalides canis
San Ignacio/    dog (45)          Ctenocephalides felis
San Ignacio     dog (6)           Pulex irritans
(Marizagua)     guinea pig (1)    Pulex irritans
                guinea pig (1)    Ctenocephalides felis

Amazonas/       dog (8)           Ctenocephalides felis
Utcubamba/      dog (1)           Pulex irritans
                dog (3)           Ctenocephalides felis
Amazonas/       dog (1)           Rhiphicephalus sanguineus
Utcubamba/      dog (1)           Boophilus spp.
Jamalca         dog (1)           Pulex irritans

                dog (45)          Ctenocephalides felis
                dog (1)           Pulex irritans
Amazonas/       cat (3)           Ctenocephalides felis
Utcubamba/      human (6)         Pediculus humanus
Lonya Grande    guinea pig (1)    Ctenocephalides felis
                guinea pig (1)    Pulex irritans

Amazonas/       fox (3)           Pulex irritans
Utcubamba/      fox (1)           Ctenocephalides felis
El Milagro


Province/       Number of    Number of
District        specimens      pools       Capture Date

                   119           7
Cajamarca/          34           2
San Ignacio/       499           26       July, 2000
San Ignacio         77           4
(Marizagua)         92           5
                    20           1

Amazonas/          190           10
Utcubamba/          1            1        September, 2001
                    33           2
Amazonas/           5            2        September, 2001
Utcubamba/          1            1
Jamalca             1            1

                   494           25
                    20           1
Amazonas/           35           2        June, 2001
Utcubamba/          84           5
Lonya Grande        5            1
                    12           1

Amazonas/           32           3        November, 2000
Utcubamba/          4            2
El Milagro

TOTAL              1758         102

Table 2. Species of Bartonella detected in lice, fleas and ticks
from San Ignacio (Cajamarca) and Utcubamba (Amazonas) in Peru.

bacteria             C. felis          C. canis

                    2 cat (MZ),
Bartonella          1 cat (LG)        1 cat (MZ)
clarridgeiae     1 guinea pig (MZ)

B. rochalimae       1 cat (MZ)            -

B. henselae         1 cat (MZ)            -

Bartonella sp.           -                -

bacteria            P. irritans       P. humanus

Bartonella          2 fox (EM)            -

B. rochalimae    2guinea pig (MZ)         -

B. henselae              -           1 human (LG)

                  4 guinea pig (3
Bartonella sp.       MZ, 1 LG)            -
                    1 dog (MZ)

bacteria           R. sanguineus        Total

Bartonella               -                7

B. rochalimae            -                3

B. henselae              -                2

Bartonella sp.           -                5

Table 3. Species of Rickettsia detected in lice, fleas and ticks
from San Ignacio (Cajamarca) and Utcubamba (Amazonas) in Peru.
MZ: Marizagua, LG: Lonya Grande, EM: El Milagro, CJ: Cajaruro,
JM: Jamalca

bacteria                   C. felis            C. canis

                      1 guinea pig (MZ)
                      8 cat (7 MZ, 1 LG)
Rickettsia felis        48 dog (26 MZ,        2 cat (MZ)
                      15 LG, 1 JM, 6 CJ)
                          1 fox (EM)

Rickettsia sp.     4 dog (2 CJ, 1 JM, 1 LG)       -

bacteria                P. irritans         P. humanus

                        2 dog (MZ)
Rickettsia felis     3 guinea pig (MZ)          -
                        1 fox (EM)

Rickettsia sp.        2 dog (MZ, LG)       2 human (LG)
                   2 guinea pig (MZ, LG)

bacteria           R. sanguineus    Total

Rickettsia felis         -            66

Rickettsia sp.           -            10
COPYRIGHT 2013 Universidad Nacional Mayor de San Marcos
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2013 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Author:Caceres, Abraham G.; Padilla Rojas, Carlos P.; Arias Stella, Javier; Huatuco Crisanto, Gerardo; Gonz
Publication:Revista peruana de biologia
Article Type:Report
Date:Dec 1, 2013
Previous Article:Aislamiento y caracterizacion de Escherichia coli O157:H7 a partir de carne molida de bovino en Lima-Peru.
Next Article:Siete nuevos registros de Arctiini (Lepidoptera: Erebidae: Arctiinae) para Peru.

Terms of use | Privacy policy | Copyright © 2022 Farlex, Inc. | Feedback | For webmasters |