ABSTRACT
Aims: Infections due to metallo-β-lactamase (MBL) producing Gram negative rods are a cause of high mortality and morbidity. Early detection by an economical and accurate method may improve patient outcome. This study was aimed to evaluate the diagnostic accuracy of combined disc method for MBL detection by comparing it with MBL-Etest. Methodology and Results: This cross-sectional, validation study was carried out in the Department of Microbiology, Army Medical College, National University of Sciences and Technology, Rawalpindi, over a period of six months. A total of 52 non-duplicate Gram-negative rods isolated from the routine clinical specimens and found resistant to meropenem/imipenem on Kirby Bauer Disc Diffusion method were subjected to two tests for metallo-β-lactamase detection. One was combined Disc test using imipenem with Ethylene Diamine Tetraacetic Acid (EDTA), where a strain showing an increase in zone of inhibition of combined disc of ≥ 7 mm as compared to imipenem alone, was considered as MBL producer and the other one was MBL-Etest for which results were interpreted as per manufacturer’s guidelines. Combined disc method for MBL detection was found to have a sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 97.5%, 100%, 100%, 92% and 98%. Conclusion, Significance and Impact of study: Combined disc method is an economical and reliable method for metallo-β-lactamase detection which can be used routinely in any laboratory.
ABSTRACT
Microorganisms adhere to non-living material or living tissue, and form biofilms made up of extracellular polymers/slime. Biofilm-associated microorganisms behave differently from free-floating bacteria with respect to growth rates and ability to resist antimicrobial treatments and therefore pose a public health problem. The objective of this study is to detect the prevalence of biofilm producers among Gram positive and Gram negative bacteria isolated from clinical specimens, and to study their antimicrobial susceptibility pattern. The study was carried out from October 2009 to March 2010, at the Department of Microbiology, Army Medical College/ National University of Sciences and Technology (NUST), Rawalpindi, Pakistan. Clinical specimens were received from various wards of a tertiary care hospital. These were dealt by standard microbiological procedures. Gram positive and Gram negative bacteria isolated were subjected to biofilm detection by congo red agar method (CRA). Antimicrobial susceptibility testing of those isolates, which showed positive results (slime production), was done according to the Kirby-Bauer disc diffusion technique. A total of 150 isolates were tested for the production of biofilm/slime. Among them, 81 isolates showed positive results. From these 81, 51 were Gram positive and 30 were Gram negative. All the 81(54%) slime producers showed reduced susceptibility to majority of antibiotics. Bacterial biofilms are an important virulence factor associated with chronic nosocomial infection. Detection of biofilm forming organisms can help in appropriate antibiotic choice.
ABSTRACT
Amp C beta-lactamases are cephalosporinases which hydrolyze cephamycins and are poorly inhibited by clavulanic acid. Amp C beta-lactamases confer resistance to a wide variety of antibiotics and pose both diagnostic and therapeutic challenges. The objective was to detect the frequency and antibiotic susceptibility pattern of Amp C beta-lactamase producing bacteria isolated from a tertiary care hospital of Pakistan. Organisms were isolated from various clinical specimens. First, the screening of the isolates was done by using cefoxitin disc. Screen-positive organisms were subjected to three dimensional extract test for detection of Amp C beta-lactamases. From a total of 100 organism tested, 64 organisms were positive on cefoxitin screen test. Out of these 64, 40 [62.5%] showed the presence of Amp C beta-lactamase. [E.coli n=18, K.pneumoniae n=14, K.oxytoca n=1, Enterobacter species n=5, Citrobacter freundii n=2] by three dimensional extract test. The antibiotics found out to show good activity against these resistant bacteria include meropenem and tigecycline. This is the first study to determine the frequency of Amp C beta lactamases from Pakistan. This study shows a high frequency of Amp C beta-lactamase producing isolates from a hospital, which may lead to serious therapeutic problems
Subject(s)
Humans , Drug Resistance, Microbial , Microbial Sensitivity Tests , HospitalsABSTRACT
To find out a correlation between Glycated hemoglobin [HbA1c] and random plasma glucose levels for the screening of diabetes mellitus. Analytical cross-sectional study. This study was conducted in the Department of Pathology, Army Medical College, National University of Sciences and Technology, Rawalpindi, from January 2010 to April 2010. Three hundred and fifteen patients were included in the study. HbA1c was estimated using Ion Exchange Resin separation kit of Globe Diagnostics, as per guidelines. The Plasma samples received were analyzed on fully automated chemical pathology analyzer Selectra E for random glucose estimation by Glucose Oxidase method. The gender distribution and the relationship of age with HbA1c and random plasma glucose levels were also determined. The results were interpreted using Statistical Package for The Social Sciences [SPSS] version 17. There was a direct correlation between glycated hemoglobin and random plasma glucose levels while there was no correlation between age of the patients and the HbA1c or the age and the random plasma glucose levels. We also found that for every 1% rise in HbA1c, plasma glucose level rose by 2.3mmol/L. Glycated haemoglobin can be used as a reliable, feasible and fairly accurate tool for screening of diabetes mellitus