Sm Shamsuzzaman

Isolation and molecular characterization of New Delhi metallo-beta-lactamase-1 producing superbug in Bangladesh.

INTRODUCTION New Delhi metallo-beta-lactamse-1 (NDM-1) producing superbugs create a global public health problem because of their resistance to most antibiotics. This study was conducted to determine the presence of MBL producers, including NDM-1 producers, in Bangladesh, along with the antimicrobial resistance patterns of these organisms. METHODOLOGY Thirty-five isolates resistant to imipenem by disk diffusion technique were investigated for MBL production. Minimum inhibitory concentration (MIC) of imipenem was determined by agar dilution method. MBL producers were phenotypically detected by double disk synergy test and combined disk assay. Gene encoding blaIMP-1, blaIMP-2, blaVIM-1, blaVIM-2, blaNDM-1 and class 1 integron was identified by PCR. RESULTS Thirty-one (88.57%) MBL producers were detected by PCR, 24 (68.57%) by double disk synergy test, and 30 (85.71%) by combined disk assay. Eight (22.86%) were positive for blaNDM-1, 13 (37.15%) for blaVIM-1, 21 (60.00%) for blaVIM-2, 18 (51.43%) for blaIMP-1, and 9 (25.71%) for blaIMP-2. More than one blaMBL was present in 23 (65.71%) of the isolates. MIC of imipenem of MBL producers ranged from ≥256 µg/ml to ≤8 µg/ml. All the NDM-1 producing isolates carried class 1 integron. NDM-1 producers were 100% resistant to amoxicillin, cephradine, cefuroxime, ceftazidime, cefotaxime, ceftriaxone, aztreonam, gentamicin and piperacillin, 87.5% to amikacin, 75% to ciprofloxacin, and 62.5% to co-trimoxazole and the combination of tazobactam and piperacillin. All were sensitive to colistin. CONCLUSION The results of this study provide insight into the presence of blaMBL, including blaNDM-1, in Bangladesh. Urgent epidemiological monitoring of MBL producers in Bangladesh may combat their rapid dissemination.

Antimicrobial susceptibility pattern of extended-spectrum beta-lactamases producing organisms isolated in a Tertiary Care Hospital, Bangladesh

Context: Infection caused by extended-spectrum beta-lactamases (ESBL) producing organism is a major problem regarding antibiotic resistance. Aims: The aim of this study was to find out the antibiogram of ESBL producing organisms isolated from various samples. Settings and Design: This cross-sectional study was carried out in the Department of Microbiology of a Tertiary Care Hospital, Dhaka, Bangladesh from January to June 2014. Subjects and Methods: One Hundred and seventy-nine ESBL producing Gram-negative organisms detected phenotypically by double-disc synergy test were enrolled in this study. Required data were collected from the records of the Microbiology laboratory. Results: ESBL production was detected in 16.07% (179/1114) of isolated organism. Of Escherichia coli, 15.75% were ESBL producers; 14.01% Pseudomonas spp., 36.84% Proteus spp., 18.57% Klebsiella spp., and 21.05% of Acinetobacter spp., were ESBL producers. Maximum (43.58%) ESBL producers were isolated from surgery departments, and wound swabs yielded majority (53%) of them. About 13% ESBL producers were isolated in outdoor patients mostly from community-acquired infections. Most ESBL producers were resistant to commonly used antibiotics. Carbapenems especially imipenem was the most effective drug showing excellent sensitivity; colistin and piperacillin/tazobactam also had better sensitivity result. Most of the ESBL producers showed a good sensitivity to amikacin, but all of them were highly resistant to ciprofloxacin. Conclusions: ESBL production should be detected routinely in all Microbiology laboratories. Infection control, rational use of antibiotics must be done promptly to prevent the development and spread of ESBL producing organisms.

Comparison of Sula Liquid Media and Conventional Method for Diagnosis of MDR-TB

Background: Tuberculosis is probably the most important infectious disease of human. Early diagnosis of tuberculosis and initiating prompt treatment has been the mainstay in interrupting the transmission of the infection to others in the community. Aim: The present study was aimed at evaluating and comparing the different media which are available for the diagnosis of tuberculosis and at determining their feasibility as diagnostic tests in terms of their effectiveness and affordability. Methods: 100 Z-N stain positive samples were taken from NIDCH, Mohakhali, Dhaka. All samples were cultured on LJ media for 4-6 wks and sula liquid media for 12 days. Drug sensitivity tests against isoniazid (INH), rifampicin (RIF), streptomycin (SM) and ethambutol (EMB) were done by both conventional (LJ media) and slide method and additional sensitivity were done against second line drugs such as gatifloxacin (G), kanamycin (K) and ofloxacin (OF) only by slide method. Sensitivity test against P-nitro benzoic acid (PNB) were also done to differentiate typical Mycobacterium from atypical Mycobacterium by both slide and conventional