High Prevalence of Multiple Drug Resistant and Biofilm Forming Staphylococcus aureus among HIV-Infected Patients with Suspected Pneumonia

Staphylococcus aureus is one of the major causes of life threatening pneumonia, especially in immunocompromised population. In HIV positive patients, S. aureus associated pneumonia can be either health care associated or community acquired and responsible for high rate of mortality. In this study total 102 throat swab samples of HIVInfected Patients with suspected pneumonia were collected during 2014-2016, out of them 46 samples (45.1%) were found positive for S. aureus by biochemical tests. 38 (82.6%) isolates were found multiple drug resistant while 9 (19.6%) strains showed resistance to cefoxitin antibiotic, were considered as methicillin resistant Staphylococcus aureus (MRSA). Only one strain (2%) was found vancomycin intermediate (VISA), remaining 98% isolates were sensitive to vancomycin antibiotic. In PCR test, all cefoxitin resistant strains were found positive for the presence of MecA gene. Biofilm former S. aureus were screened by tissue culture plat (TCP) methods. In TCP assay, 21 (45.6 %) isolates were confirmed as high biofilm formers (OD value > 0.250), 16 (34.8 %) were moderate biofilm formers (OD valuesbetween 0.150 to 0.250), while 9 (19.6 %) were low biofilm formers (OD value < 0.150). A significant association was found among multiple drug resistance and high biofilm formation (p value < 0.05). High prevalence of biofilm forming MDR isolates in airways of pneumonia suspected HIV patients is matter of great concern as poor antibiotic response may cause more severe diseases with increasing cost and duration of treatment. The MecA gene might be a cause of methicillin resistance among MRSA isolates.