ABSTRACT
Background: Coagulase negative Staphylococci (CONS) are normal human microbiota and sometimes cause infections, often associated with implanted devices, such as joint prosthesis, shunts and intravascular catheters, especially in very young, old and immunocompromised patients. These infections are difficult to treat because of the risk factors and the multiple drug resistant nature of the organisms. The study is undertaken to speculate CONS isolates from various clinical samples and to determine antibiotic susceptibility pattern of CONS by Kirby Bauer disc diffusion method. Methods: A total of 134 clinically significant CONS isolated from pus, urine, blood, fluid, sputum, ear swabs, endotracheal tube, ophthalmic, semen and nail samples. These isolates initially identified by colony morphology, Gram staining, catalase test, slide coagulase test, tube coagulase test and mannitol fermentation. Speciation of CONS was done by novobiocin resistance test, urease activity, ornithine decarboxylase and aerobic acid production from mannose. Results: S. epidermidis is the most frequent isolate 62 (46.3%) followed by S. saprophyticus 38(28.4%), S. haemolyticus 27(20.1%), S. lugdunensis 3(2.2%). S. warneri 3(2.2%), S. cohinii 1(0.7%). Antibiotic susceptibility testing of the isolates showed maximum resistance to penicillin 128 (95.5%) and ampicillin118 (88%) followed by erythromycin 96 (71.6%), cefoxitin 89 (66.4%), gentamicin 33(24.6%), piperacillin & tazobactam 31(23.8%), amoxicillin & clavulanic acid 25 (18.7%), linezolid 23 (17.2%), levofloxacin 9 (6.7%), vancomycin & teicoplanin 2 (1.5%), tigecycline 1 (0.7%). Conclusion: S. epidermidis is the more common isolate identified and CONS are often resistant to multiple antibiotics (Penicillin, ampicillin) & glycopeptides have been considered as the drugs of choice for the management of infections caused by these organisms.
ABSTRACT
Background: The Biofilms are densely packed communities of microorganisms consisting of layers of cell clusters embedded in a matrix of extracellular polysaccharide called polysaccharide intercellular adhesin. This layer impedes the delivery of antibiotics to the biofilm forming microbial cells leading to emergence of drug resistance. Staphylococci are commensal bacteria on the human skin and mucous membranes. So it may be easily introduced as a contaminant during the surgical intervention. So, this study was conducted to identify the Biofilm producing strains from clinical isolates of Staphylococci. Methods: A total of 182 non-repetitive clinical strains of Staphylococci isolated from various clinical samples from Feb 2014 to Oct 2014 were included in the study. All the isolates were identified using standard microbiological procedures. All the samples were tested for biofilm production by modified Congo-red agar method and tube method. Results: Out of 182 samples that were included in the study, a total of 90 (49.45%) samples showed biofilm formation of which 58 (75.32%) were methicillin resistant and 32 (30.47%) were methicillin sensitive. Also these strains were resistant to other antibiotics. Conclusion: Our study showed biofilm production by methicillin resistant strains which were also multidrug resistant. Treatment of methicillin resistant strains of Staphylococci is one of the most challenging task for the clinicians and the microbiologists. So they should be routinely screened for biofilm formation in order to prevent emergence and spread of multidrug resistant strains.
ABSTRACT
Background: All postoperative surgical infections occurring in an operative site are termed surgical site infections (SSI). Superficial incisional surgical site infection occurs within 30 days after the operation and infection involves only skin or subcutaneous tissue of the incision and represents a substantial burden of disease for patients and health services. The study was conducted to know the incidence of surgical site infection in our hospital, risk factors associated with it and the antibiotic susceptibility pattern of the pathogens. Methods: This prospective study was carried out in the Department of Microbiology at Dr B R AMC for a period of 1 year from Jan 2013to Jan 2014. Samples of SSI received in the Microbiology laboratory were processed and Data collected. Results: The overall surgical site infection rate in our hospital during the study period is 4.3%. Staphylococcus aureus (S. aureus) was the most common isolate obtained followed by Escherichia coli (E. coli) and Coagulase negative Staphylococcus (CONS). Other organisms isolated were Pseudomonas aeruginosa, Enterococcus, Klebsiella pneumoniae and Proteus mirabilis. Among them, 88.8% of S. aureus and 50% of CONS isolates were methicillin-resistant strains. 80% of E. coli and 100% of Klebsiella species were ESBL producers. 50% of Enterococci were Vancomycin resistant. Risk factors like diabetes mellitus and duration plays a significant role in causing surgical site infection. Conclusion: Implementation of an effective infection control programme and judicious use of antibiotic prophylaxis reduces the incidence of SSI in the hospital.