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BMC Infectious Diseases

Open Access

Trimethoprim sulfamethoxazole drug resistance with co resistance to extended spectrum β-lactam antibiotics among bacterial isolates from HIV patients

  • Marimuthu Ragavan Rameshkumar1,
  • Nallusamy Vijaykanth1,
  • Ramachandran Vignesh2,
  • Pachamuthu Balakrishnan2,
  • Suniti Solomon2 and
  • Narasingam Arunagirinathan1Email author
BMC Infectious Diseases201414(Suppl 3):P57

Published: 27 May 2014


Trimethoprim-sulfamethoxazole (TMP-SMX) is a broad spectrum antimicrobial agent and also reduces the mortality among adults and children when used as prophylaxis against opportunistic infections in HIV infected patients. Drug resistant to TMP-SMX along with Extended spectrum β-lactamase (ESBL) production among Enterobacteriaceae is creating major therapeutic problem in clinical settings for treating the bacterial infections among HIV individuals.


TMP-SMX drug resistance among the isolates was identified using Kirby-Bauer disc diffusion method and ESBL production by combination disc method (CDM). Cefotaxime (30µg) and cefotaxime/clavulanic acid (30μg/10μg) discs were placed 20 mm apart on the agar surface. Similarly, the ceftazidime (30µg) and ceftazidime/clavulanic acid (30μg/10μg) discs were also placed. After incubating overnight at 37°C, a ≥ 5mm increase in the zone diameter was interpreted as positive for ESBL production. Statistical analysis was done using SPSS software version 15.0.


A total of 103(40 Escherichia coli, 15 Klebsiella pneumoniae, 13 Pseudomonas aeruginosa, 10 Klebsiella oxytoca, 8 Proteus mirabilis, 2 Proteus vulgaris, 11 Staphylococcus aureus, 3 Staphylococcus epidermidis and 1 Streptococcus sp.) bacterial strains were isolated from HIV patients. Among these 65(63.10%;p=0.008) isolates were resistance to TMP-SMX and only 40(38.83%;p=0.023) isolates were resistant to extended spectrum β-lactam antibiotics. Twenty nine ESBL producers from HIV patients were found to be co resistant to TMP-SMX. All ESBL producing isolates showed resistance to ceftazidime and also for ceftazidime/clavulanic acid combination.


A rapid increase in the use of prophylactic TMP-SMX might be responsible for the TMP-SMX drug resistance among opportunistic bacterial infections in HIV patients.

Authors’ Affiliations

PG & Research Department of Microbiology and Biotechnology, Presidency College (Autonomous)
YRG Centre for AIDS Research and Education


© Rameshkumar et al; licensee BioMed Central Ltd. 2014

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated.