Prevalence And Current Antibiogram Of Staphylococci Isolated From Various Clinical Specimens In A Tertiary Care Hospital In Pondicherry

摘要

Background:Prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and Coagulase–negative staphylococcus (CONS)is reported to be increasing globally.Objectives:To find the magnitude of staphylococci infectionand currentsusceptibility pattern in a tertiary care teaching hospital in Pondicherry.Materials and Methods:This cross sectional study comprised of 550 coagulase-positive and coagulase-negative staphylococci isolated from various clinical specimens (pus, sputum, body fluids, high vaginal swab, wound swabs and tracheal aspirates) from patients at our hospital over a period of 1 year. The antimicrobial susceptibility test was performed for the isolates as per Clinical and Laboratory Standards Institute (CLSI) guidelines. Methicillin resistance was detected using oxacillin and cefoxitin disc diffusion method, and oxacillin screen agar method.Results:Most of the staphylococcal isolates were from patients admitted in surgery wards, followed by orthopedics and obstetrics and gynecology. Of the total 550 Staphylococcus isolates, 284 (51.63%) were methicillin sensitiveStaphylococcusaureus(MSSA), 59 (10.7%) were methicillin resistantStaphylococcusaureus(MRSA) and 207 (49.09%) were CoNS. Methicillin resistance was seen in 17.2% (59/ 343) isolates ofS. aureusand 23.2% (48/ 207) of CoNS. The sensitivity of MRSA to vancomycin and clindamycin were 100% and 78% respectively. The resistance of MRSA was very high for co-trimoxazole (88.1%) and ciprofloxacin (81.4%). The MR-CoNS showed very high resistance for co-trimoxazole (79.2%) and erythromycin (72.9%).Conclusion:Regularsurveillance of hospital- associated infection and monitoring of antibiotic susceptibility pattern is required to reduce prevalence of methicillin resistance among Staphylococci. Introduction Staphylococcus aureuscauses a wide range of infections. These can be broadly divided into community and hospital-acquired infections. Community acquired infections include the following: toxin mediated disease (e.g. food poisoning and toxic shock syndrome), infections affecting the skin and soft tissue (boils, impetigo, cellulitis and myositis), infection of bones and joints, infections relating to other deep sites (endocarditis, abscess formation in liver, spleen and other sites) and infections of the lung and urinary tract. Nosocomial or hospital acquired infections include the disease already mentioned and more commonly surgical wound infections, ventilator associated pneumonia, bacteremia associated with intravenous devices and other prosthetic material such as CSF shunts, prosthetic joints and vascular graft.1Infection due toS. aureusimposes a high and increasing burden on health care resources. The increase in the incidence of infections due toS. aureusis partially a consequence of advances in patient care and also of the pathogen's ability to adapt to a changing environment. The most prevalent Staphylococcal species and subspecies in human infection are S.aureus,S. epidermidis,S. haemolyticus,S. saprophyticusfollowed byS. hominis,S. warneriandS. lugdunesis.1Methicillin introduced in 1961 was the first of the semi-synthetic penicillinase resistant penicillin developed in response to widespread penicillin resistance in S. aureus. Its introduction was soon followed by emergence of methicillin resistance, which spread in waves across hospital in many countries.2InS. aureus, methicillin resistance is defined as resistance to the isoxazoyl penicillins such as methicillin, oxacillin and flucloxacillin. The frequency of Methicillin resistantS. aureus(MRSA) infections continues to grow in hospital-associated settings, and more recently, in community settings globally. Methicillin resistance is not confined toS. aureus. Several species of staphylococcus show methicillin resistance includingS. epidermidis, S. haemolyticus,S. hominis, S. capitis, S. warneri, S. caprae, S. sciuri.1Only a few reports regarding the antimicrobial susceptibility ofS. aureusin Pondicherry are availab