Carbapenem resistant acinetobacter-A major pathogen in a Tertiary Care Hospital

Objective: To determine the frequency of carbapenem resistant Acinetobacter in the Military Hospital Rawalpindi, Pakistan

Study Design: Descriptive study

Place and Duration of Study: Department of Microbiology, Army Medical College, from Oct, 2012 to Feb, 2013

Material and Methods: Clinical specimens like naso-bronchial lavage, blood, pus, sputum and catheter tips were inoculated on blood agar and Mac Conkey agar while the urine samples were inoculated on Cystine Lactose Electrolyte Deficient [CLED] agar. Acinetobacter spp. isolated, were later subjected to antimicrobial susceptibility testing using the modified Kirby-Bauer disc diffusion method on Mueller Hinton agar as per Clinical Laboratory and Standards Institute [CLSI] guidelines

Results: Out of a total of 85 Acinetobacter spp. 62 isolates were found to be carbapenem resistant. They were also found to be 100% resistant to ciprofloxacin and ceftriaxone thus becoming multidrug resistant followed by tazobactam piperacillin [98%] and trimethoprim sulphamethoxazole [92%]. Minimum resistance was seen against tigecycline being 21%

Conclusion: It is concluded from our study that there is a high frequency [72.94%] of resistance to carbapenems in Acinetobacter spp. in our setup which is associated with increased morbidity and mortality due to limited treatment options

Coagulase negative staphylococci - a fast emerging threat

To determine the frequency of isolation of coagulase-negative staphylococci and their resistance to methicillin over a period of time. The descriptive cross-sectional study was carried out at Army Medical College, Rawalpindi, from June 2009 to May 2012, and comprised clinical samples mostly from patients admitted to the intensive care unit. They were inoculated onto appropriate culture media depending upon the specimen. After 24-hour incubation at 35°C, coagulase-negative staphylococci were identified on the basis of colony morphology, gram staining, a positive catalase and a negative tube coagulase test. Methicillin resistance among the isolated staphylococci was determined using a 30microg Cefoxitin disc as per the Clinical and Laboratory Standards Institute protocol. Number of coagulase-negative staphylococci for each year and their methicillin resistance rates were calculated. A comparison was made with methicillin resistant staphylococcus aureus] isolated during the same period. Of the total 1331 specimens studies over three years, 581[43.65%] were coagulase-negative staphylococci. The rate of coagulase-negative staphylococci and methicillin resistance was higher each year; 110[26.6%] in May 2009-Jun 2010, 134[36.5%] in 2011, and 337[61%] in 2012. Methicillin resistance rates also increased from 25[22.7%] to 46[34.3%] and then to 201[59.6%] in 2012.Maximum isolated specimens came from blood 311[53.5%], followed by pus/swabs 204[35.1%]. The frequency of isolation of coagulase-negative staphylococci and its methicillin resistance among hospitalised patients is on the rise

Frequency and antibiogram of vancomycin resistant enterococcus in a tertiary care hospital

To determine the frequency of Vancomycin Resistant Enterococcus [VRE] in a tertiary care hospital of Rawalpindi, Pakistan. Observational, cross-sectional study. Department of Microbiology, Army Medical College, Rawalpindi, from May 2011 to May 2012. Vancomycin resistant Enterococcus isolated from the clinical specimens including blood, pus, double lumen tip, ascitic fluid, tracheal aspirate, non-directed bronchial lavage [NBL], cerebrospinal fluid [CSF], high vaginal swab [HVS] and catheter tips were cultured on blood agar and MacConkey agar, while the urine samples were grown on cystine lactose electrolyte deficient agar. Later the antimicrobial susceptibility testing of the isolates was carried out using the modified Kirby-Bauer disc diffusion method on Mueller Hinton agar. A total of 190 enterococci were isolated. Of these, 22 [11.57%] were found to be resistant to vancomycin. The antimicrobial sensitivity pattern revealed maximum resistance against ampicillin [86.36%] followed by erythromycin [81.81%] and gentamicin [68.18%] while all the isolates were 100% susceptible to chloramphenicol and linezolid. The frequency of VRE was 11.57% with the highest susceptibility to linezolid and chloramphenicol