African Journal of Biotechnology Vol. 6 (8), pp. 1035-1047, 16 April 2007   

ISSN 1684–5315 © 2007 Academic Journals        

Full Length Research Paper

Antibiotic resistance profiles and relatedness of enteric bacterial pathogens isolated from HIV/AIDS patients with and without diarrhoea and their household drinking water in rural communities in Limpopo Province South Africa

Obi C. L. ¹*, Ramalivhana J.², Momba M.N.B.⁵, Onabolu B.⁶, Igumbor J.O.³, Lukoto M.³, Mulaudzi T.B.⁴, Bessong P.O.², Jansen van Rensburg E.L.⁶, Green E² and Ndou S²

¹College of Agriculture and Environmental Sciences, School of Agriculture and Life Sciences, University of South Africa, Pretoria, South Africa.

²Department of Microbiogy, University of Venda, South Africa

³Department of Public Health University of Venda, South Africa

⁴Department of Statistics, University of Venda, South Africa.

⁵Department of Water Care, Tshwane University of Technology, Arcadia Campus, Pretoria.

⁶Department of Microbiology, University of Limpopo.

*Corresponding author. E -mail :  obicl@unisa.ac.za, Tel : + 27 82 422 7580, Fax :  + 27 12 352 4032

Accepted 8 December, 2006

Antibiotic resistance profiles and the correlation of enteric bacterial pathogens from HIV positive indivi-duals with and without diarrhoea and their household drinking water were determined using the Kirby Bauer disk diffusion and polymerase chain reaction methods respectively. The sef gene of Salmonella enteritidis was amplified with the primer pair sefA-1 and sefA-2. The fliC gene of Salmonella typhimurium was amplified with the primer pair flicA-1 and flicA-2. Heat-labile toxin (LT) primers (Lta and LTb) were used to amplify Escherichia coli isolates and VirA1 and VirA2 for the Vir A gene of Shigella dysenteriae. Results of antibiotic resistance profiles of enteric bacterial pathogens isolated from stool samples of HIV positive and negative individuals with and without diarrhea and their household drinking water showed very similar drug resistance patterns. Over 90% of all the organisms isolated from the various study cohorts showed resistance to penicillin, cloxacillin and amoxicillin. Conversely, almost all the organisms were sensitive to ciprofloxacin, gentamycin, meropenem and imipenem. About 50% of E. coli isolated from the various study cohorts showed multiple antibiotic resistance to penicillin, amoxicillin, ampicillin, erythromycin, tetracycline, doxycycline and cotri-moxazole ( P^R, A^R, AP^R, E^R, T^R, DXT^R, and TS^R ) whereas less than 10% resistance was consistently reported for ofloxacin, gentamycin, meropenem cefotaxime, cefuroxime and imipenem ( OFX^S, GM^S, MEM^S, CTX^S, CXM^S and IMI^S ). The majority of Salmonella and Shigella isolates from all the groups were sensitive to ciprofloxacin, gentamicin, amikacin, meropenem, imipenem, nalidixic acid, kanamycin, piperacillin-tazo bactam, cefuroxime, doxycyclin, cefepime and ceftazidime (CIP^S, GM^S, AK^S, MEM^S, IMI^S, NA^S, KN^S, DXT^S, CXM^S, CPM^S, CAZ^S and PTZ^S). For Campylobacter, over 30% of the isolates were resistant to erythromycin, ampicillin, tetracycline, cotrimoxazole and ceftazidime (E^R, AP^R TS^R and CAZ^R) whereas over 85% were susceptible to ciprofloxacin, ofloxacin, gentamycin, amikacin, mero-penem, and nalidixic acid (CIP^S, OFX^S, GM^S, AK^S, MEM^S and NA^S). In addition to penicillin, amoxicillin, ampicillin and erythromycin, Aeromonas and Plesiomonas spp were more resistant to chloramphenicol, but were susceptible to ciprofloxacin, gentamycin, amikacin, meropenem, imipenem and nalidixic acid (CIP^S, GM^S, AK^S, MEM^S, IMI^S and NAS). Polymerase Chain Reaction (PCR) experiments using targeted species genes of S. enteritidis, S. typhimurium, E. coli, Sh. dysenteriae showed that isolates from stool samples of HIV positive and HIV negative individuals with and without diarrhoea were also present in the household drinking water of the same study cohorts, suggesting that drinking water may have been the sources of the organisms in stool sample. Furthermore, by showing that the primers were able to amplify the genes in both clinical and environmental isolates, the link between the virulence of the pathogens was established.

Key words: Enteric, Bacteria, Pathogens, Antibiotics, HIV/AIDS, Household, Water, Diarrhoea.