Bacteriological study of surgical site infections in a tertiary care hospital at Miraj, Maharashtra state, India

Background: Surgical site infections (SSI) are one of the common post-operative complications. Apart from bacterial contamination of wound, various patient and environment related factors play role in development and outcome of SSI. The present study is undertaken to study the frequency of SSI with reference to factors contributing to it and the antimicrobial susceptibility pattern of the causative organisms.Methods: This single-observer, cross-sectional, complete-enumeration prospective study was carried out over a period of one year. 196 pus samples from cases of surgical site infections were processed for gram staining, culture, biochemical identification tests and antimicrobial susceptibility testing. Methicillin-Resistant Staphylococcus aureus (MRSA) strains were detected by using oxacillin and cefoxitin disk diffusion and minimum inhibitory concentration (MIC) of oxacillin was tested by broth dilution technique.Results: The overall frequency of SSI was 6.17%. Most common isolates were Staphylococcus aureus, coagulase negative Staphylococci (CONS), E. coli and Pseudomonas aeruginosa. The frequency of MRSA was 8.6%. The maximum frequency was among patients operated on emergency basis in surgical department.Conclusions: The most important determinants for SSI were emergency surgery and presence of co-morbid conditions. The frequency of occurrence was age-dependent, with maximum rate of SSI in males and females in the third and sixth decades of life, respectively

Hospital-based study of methicillin-resistant Staphylococcus aureus in surgical site infections with special reference to determination of environmental and human sources

Background: Surgical site infection (SSI) due to methicillin-resistant Staphylococcus aureus (MRSA) is associated with increased morbidity and mortality. Carriage of MRSA by healthcare personnel is a potential source for SSI. The present study was carried out to study the frequency of MRSA in SSI; to identify the most suitable identification test for routine use; and to determine the environmental and human source of MRSA.Methods: In this prospective study, 195 SSI-pus samples were processed for primary staining, culture and biochemical tests. Cefoxitin and oxacillin disc diffusion test and oxacillin broth dilution test were used to detect MRSA and to determine the minimum inhibitory concentration (MIC) among the identified S. aureus. Environment was sampled periodically using air settle plates and swabs from various sites.  Healthcare personnel were screened for nasal and hand carriage of MRSA.Results: Of the 205 isolates, 46 were S. aureus, and among these, 18 strains were MRSA. There was no discrepency in the result by any of the three methods used. MRSA carriage, found on the hands of three healthcare personnel, had same anti-biogram as those strains simultaneously obtained from the patients. All three personnel responded to Mupirocin treatment. No MRSA was obtained from the environment.Conclusions: MRSA is an important source of SSI. Cefoxitin disc diffusion method seems suitable technique for routine use. Periodic screening of healthcare workers for carriage of MRSA will prevent outbreaks of nosocomial infections

Hospital-based study of methicillin-resistant Staphylococcus aureus in surgical site infections with special reference to determination of environmental and human sources

Background: Surgical site infection (SSI) due to methicillin-resistant Staphylococcus aureus (MRSA) is associated with increased morbidity and mortality. Carriage of MRSA by healthcare personnel is a potential source for SSI. The present study was carried out to study the frequency of MRSA in SSI; to identify the most suitable identification test for routine use; and to determine the environmental and human source of MRSA.Methods: In this prospective study, 195 SSI-pus samples were processed for primary staining, culture and biochemical tests. Cefoxitin and oxacillin disc diffusion test and oxacillin broth dilution test were used to detect MRSA and to determine the minimum inhibitory concentration (MIC) among the identified S. aureus. Environment was sampled periodically using air settle plates and swabs from various sites.  Healthcare personnel were screened for nasal and hand carriage of MRSA.Results: Of the 205 isolates, 46 were S. aureus, and among these, 18 strains were MRSA. There was no discrepency in the result by any of the three methods used. MRSA carriage, found on the hands of three healthcare personnel, had same anti-biogram as those strains simultaneously obtained from the patients. All three personnel responded to Mupirocin treatment. No MRSA was obtained from the environment.Conclusions: MRSA is an important source of SSI. Cefoxitin disc diffusion method seems suitable technique for routine use. Periodic screening of healthcare workers for carriage of MRSA will prevent outbreaks of nosocomial infections