Bacteria isolated from bloodstream infections at a tertiary care hospital in Dar es Salaam, Tanzania--antimicrobial resistance of isolates.
Isolates were identified by their phenotypic and biochemical characterisation. The antibiotic susceptibility was tested by disk diffusion methods following the Clinical and Laboratory Standards Institute (CLSI) criteria. MDR Gram-negative strains were defined to be resistant to meropenem, piperacillin-tazobactam, cefepime, amoxicillin-clavulanic acid and amikacin. The 5 MDR Klebsiella pneumoniae from 1 133 isolates were isolated from urine in 3 patients and from purulent material in 2. Isolates identified included K. pneumoniae (468), Escherichia coli (413), Salmonella typhi/paratyphi A, B group (32), S. aureus (110), S. citreus (2), Pseudomonas aeruginosa (106) and Proteus spp. (2). All 3 MDR isolates from urine were susceptible to tigecycline, 2 to ciprofloxacin and 1 each to ofloxacin or rifampicin. Both MDR isolates from purulent materials were susceptible to tigecycline, ofloxacin and chloramphenicol, while 1 each was susceptible to aztroenam or rifampicin.
An annual rather than a 5-year update (1) on local antibiotic susceptibility profiles would be useful for clinicians, who would be able to refer to the previous local antimicrobial susceptibility pattern during pilot antibiotic prescription for their patients. This would be useful before results of in vitro susceptibility of isolates are available. For example, the first-line, inexpensive antimicrobials (1) that were developed in the 1940s and 1950s would not be the initial choice among clinicians managing patients with severe MDR. However, they might be the only option available in some cases, even if the in vitro susceptibility profiles are dismal. (1)
The technical assistance of Ms Umanga Chattri is acknowledged.
Subhash C Arya
Sant Parmanand Hospital
(1.) Moyo S, Aboud S, Kasubi M, Maselle SY. Bacteria isolated from bloodstream infections at a tertiary care hospital in Dar es Salaam, Tanzania--antimicrobial resistance of isolates. S Afr Med J 2010;100:835838.
Dr S Moyo replies: Our 5-year retrospective analysis was aimed at establishing the aetiological agents and their antimicrobial resistance patterns. We established that MRSA and ESBL were also of public health importance in our settings. Since it was a retrospective analysis we could not investigate for MDR. We have recently shown a high prevalence of ESBL-producing E. coli and Klebsiella spp. strains from urine samples, and most of the ESBL-producing isolates were MDR, limiting available therapeutic choices. (1) We are currently conducting another prospective study to monitor the trends of MRSA and to determine the presence of MDR. These results, together with the previous ones, will guide antimicrobial prescribing practice by our clinicians. MDR bacteria may be susceptible to the first-line antibiotics, but this was not apparent in our study. In vitro susceptibility results may not necessarily reflect what would happen in vivo. Our view is that when managing patients with severe infections due to MDR organisms, the first-line antibiotics should not be used in order to reduce morbidity and mortality that could be associated with life-threatening infections. In tertiary hospitals like ours or the authors', first-line antibiotics might not be the only option available for management of such cases, as suggested.
(1.) Moyo SJ, Aboud S, Kasubi M, Lyamuya EF, Maselle SY. Antimicrobial resistance among producers and non-producers of extended spectrum beta-lactamases in urinary isolates at a tertiary hospital in Tanzania. BMC Research Notes 2010;3:348 (24 December 2010).
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|Author:||Arya, Subhash C.; Agarwal, Nirmala|
|Publication:||South African Medical Journal|
|Article Type:||Letter to the editor|
|Date:||Feb 1, 2011|
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