Assessment of resistance in multi drug resistant tuberculosis patients

Objective: To study MDR-TB isolates and to identify primary and secondary resistance at microbiology laboratory Aga Khan University, Karachi, Pakistan. Methods: All samples positive for Mycobacterium tuberculosis (MTB) received during January - September 2004 were reviewed for drug resistance pattern as well as for history of previous antituberculous drugs exposure. Results: Out of 216 Mycobacterium tuberculosis cultures, 138 (64%) showed resistance to one or more agents. Multi drug resistance (MDR) was observed in 102 (47%) isolates. Of 138 drug resistant isolates; primary resistance to any one or more agent was noted in 31(39%) and secondary (acquired) resistance in 107 (79%) isolates. On analysis of the 102 MDR-TB strains 8 (10%) showed primary resistance while 94 (69%) showed secondary resistance. CONCLUSION: In this group MDR-TB was mainly associated with previous anti-tuberculous treatment. However, primary MDR was also observed and reflects dissemination of MDR cases within the community

Mycobacterial contamination of bronchoscopes: Challenges and possible solutions in low resource settings

The use of bronchoscopes has increased in tuberculosis (TB) diagnostics to circumvent the diagnostic challenges that are associated with low sputum volume and smear-negative TB. In healthcare facilities situated in low income countries that have a high burden of TB, adequate decontamination of bronchoscopes is a challenge and often overlooked to save on time and costs. This amplifies the risk of outbreaks and pseudo-outbreaks due to Mycobacterium tuberculosis and nontuberculosis mycobacteria. In this minireview, we review published literature of contaminated bronchoscopes causing pseudo-outbreaks of M. tuberculosis and nontuberculosis mycobacteria in an effort to determine common sources, and possible mitigation strategies in low-resource settings

Inducible clindamycin resistance due to expression of erm genes in Staphylococcus aureus: report from a tertiary care Hospital Karachi, Pakistan

OBJECTIVE: To assess the frequency of phenotypic expression of inducible resistance of clindamycin due to expression of erm genes, in clinical isolates of Staphylococcus aureus (S. aureus), by double disk diffusion test (D-test). METHOD: This was a cross sectional study conducted in the clinical laboratory of Aga Khan University Hospital, Karachi. A total of 2432, non duplicate clinical isolates of S. aureus, consisting of 1562 methicillin sensitive S. aureus (MSSA) and 870 methicillin resistant S. aureus (MRSA), were selected from February 2007 to January 2008. One hundred and thirty eight isolates of S. aureus were selected based on discordant resistance pattern (erythromycin resistant and clindamycin sensitive) on Kirby Bauer Disk Diffusion test and phenotypic expression of inducible resistance was assessed using D-test. RESULT: Analysis of 2432 isolates showed that 64% (n=1553) were susceptible to both clindamycin and erythromycin by disc diffusion method, while 30% (n=741) showed constitutive resistance (in vitro resistance to both drugs). 6% (n=138) isolates showed clindamycin-erythromycin discordance on disc diffusion (in vitro sensitive to clindamycin and resistant to erythromycin). Among the discordant isolates 72% (n=99) had inducible resistance phenotype detected by D-test and of these 85 isolates (62%) were MRSA. CONCLUSION: Inducible resistance is common in our clinical isolates; D-test (a simple phenotypic test) should be performed on all S. aureus isolates showing clindamycin-erythromycin discordance on disc diffusion, to avoid erroneous reporting resulting in treatment failure

Dissemination and spread of New Delhi metallo-beta-lactamase-1 superbugs in hospital settings

Objective: To find out frequency of isolation of carbapenem-resistant enterobacteriaceae and the predominantly responsible metallo-beta-lactamasegene in a hospital setting. Methods: The descriptive, cross-sectional study was conducted from May 2009 to June 2012 at the Aga Khan University Hospital, Karachi, and comprised non-duplicate clinical carbapenem-resistant enterobacteriaceae isolates obtained from different collection units across Pakistan. Kirby-Bauer disk diffusion screening of carbapenem-resistant enterobacteriaceae was confirmed by minimum inhibitory concentration using E-test. Polymerase chain reaction assay was performed to detect blaKPC, blaNDM-1, blaIMP, and blaVIM genes. In addition variable number tandem repeat typing was performed on selected cluster of New Delhi metallo-beta-lactamase-1- positive Klebsiella pneumoniae. Results: Of the 114 carbapenem-resistant enterobacteriaceae isolates, 104(94%) tested positive for blaNDM-1 gene. At 68(66%), Klebsiella pneumoniae was the most frequent species isolated, followed by E.coli 33(31%). Moreover, 89(78%) of the blaNDM-1 gene positive Klebsiella pneumonia isolates were from the clinical samples of patients admitted to the critical care units and 75(66%) were from neonates and the elderly. Of the 65(67%) patientssuffering from bacteraemia and sepsis, 32(57%) had expired, of which 22(60%) were aged \u3c1 month. Variable number tandem repeat analysis of hospital-acquired New Delhi metallo-beta-lactamase-1-positive Klebsiella pneumoniae showed similarities between the isolates. Conclusion:New Delhi metallo-beta-lactamase-1-positive enterobacteriaceae was found widely disseminated in major hospitals across Pakistan. Patients at extreme ages and those in critical care units were found to be the most affected with fatal outcome

Increase in isolation of extended spectrum beta lactamase producing multidrug resistant non typhoidal Salmonellae in Pakistan.

Background:Increasing resistance to quinolones and ceftriaxone in non typhoidal Salmonellae is a global concern. Resistance to quinolone and 3rd generation cephalosporin amongst non typhoidal Salmonellae (NTS) from Pakistan has been reported in this study. Methods: Retrospective analysis of laboratory data was conducted (1990-2006). NTS were isolated and identified from clinical samples using standard microbiological techniques. Antimicrobial susceptibility testing was performed by Kirby Bauer. Extended spectrum beta lactamase production (ESBL) was detected using combined disc method. Ciprofloxacin sensitivity was detected by nalidixic acid screening method. Minimum inhibitory concentration (MIC) of ciprofloxacin was determined by agar dilution method. Statistical analysis was performed using SPSS version 13. Results: Analysis of 1967 NTS isolates showed a significant increase in ciprofloxacin resistance from 23% in 2002 to 50.5% in 2006, with increased mean MIC values from 0.6 to 1.3 ug/mL. Ceftriaxone resistant NTS also increased and ESBL production was seen in 98.7% isolates. These isolates exhibited high resistance against amoxicillin clavulanic acid (57%), gentamicin (69%), amikacin (44%) and piperacillin tazobactam (30%). No resistance to carbapenem was seen. Ceftriaxone resistance was significantly higher in childrenyear, in invasive isolates and in Salmonella Typhimurium. Conclusion: Increase in quinolone and ceftriaxone NTS is a serious threat to public health requiring continuous surveillance and use of appropriate screening tests for laboratory detection

Antimicrobial susceptibility against metronidazole and carbapenem in clinical anaerobic isolates from Pakistan

Background: Globally metronidazole and carbapenem resistance in anaerobic organisms is increasing necessitating continuous surveillance to guide selection of empirical treatment. In this study we have determined metronidazole resistance in anaerobes using MIC Evaluator strips (M.I.C.E strips). Carbapenem resistance was evaluated only in metronidazole resistant isolates.Material and methods: The study was conducted at the Aga Khan University (AKU) Hospital laboratory, Karachi, Pakistan (2014–2017). Metronidazole and imipenem resistance was evaluated using M.I.C.E strips and minimum inhibitory concentrations (MICs) were interpreted using Clinical Laboratory Standards Institute (CLSI) criteria. Clinical details including demographics, prolonged hospital stay, malignancy, transplant, dialysis, diabetes, site of infection and outcome were analyzed for association with metronidazole resistance. Results: Of the 223 clinically significant isolates, 39 (17.5%) were metronidazole resistant (excluding the inherently resistant organisms; for example Cutibacterium species). Imipenem resistance was determined in 29 metronidazole resistant isolates and of these 7 (24.1%) were found to be resistant. Proportion of metronidazole resistant strains was highest amongst Bacteroides species. A significant increase in metronidazole resistance from 12.3% in 2010–2011 to 17.5% in the current study was found. Carbapenem resistance also emerged in the period 2014–2017. Isolates from malignancy and transplant patients showed lower odds of developing metronidazole resistance (0.003(95% CI: 1.7–17.9)). Prolonged hospital stay was not associated with metronidazole resistance (1.1((95% CI: 0.5–2.5)).Conclusion: The rising trend of metronidazole resistance and emergence of carbapenem resistance in anaerobic bacteria is alarming. Continued surveillance with strengthening of laboratory capacity regarding anaerobic susceptibility testing is urgently needed in Pakistan

Lipid A-Ara4N as an alternate pathway for (colistin) resistance in Klebsiella pneumonia isolates in Pakistan

Objectives: This study aimed to explore mechanism of colistin resistance amongst Klebsiella pneumoniae isolates through plasmid mediated mcr-1 gene in Pakistan. Carbapenem and Colistin resistant K. pneumoniae isolates (n = 34) stored at - 80 °C as part of the Aga Khan University Clinical Laboratory strain bank were randomly selected and subjected to mcr-1 gene PCR. To investigate mechanisms of resistance, other than plasmid mediated mcr-1 gene, whole genome sequencing was performed on 8 clinical isolates, including 6 with colistin resistance (MIC \u3e 4 μg/ml) and 2 with intermediate resistance to colistin (MIC \u3e 2 μg/ml).Results: RT-PCR conducted revealed absence of mcr-1 gene in all isolates tested. Whole genome sequencing results revealed modifications in Lipid A-Ara4N pathway. Modifications in Lipid A-Ara4N pathway were detected in ArnA_ DH/FT, UgdH, ArnC and ArnT genes. Mutation in ArnA_ DH/FT gene were detected in S3, S5, S6 and S7 isolates. UgdH gene modifications were found in all isolates except S3, mutations in ArnC were present in all except S1, S2 and S8 and ArnT were detected in all except S4 and S7. In the absence of known mutations linked with colistin resistance, lipid pathway modifications may possibly explain the phenotype resistance to colistin, but this needs further exploration

Impact on Health and Nutrition Outcomes in Sindh Province, Pakistan

We independently conducted the impact assessment of the Tawana Pakistan Project (a school?based feeding programme to improve the nutritional status of primary school girls in impoverished rural districts of Pakistan). The evaluation was conducted among school?going girls in four districts of Sindh, Pakistan. Pre? and post?intervention data was collected for anthropometric measurements, nutritional status and physical examination. Paired analysis of 1,028 girls (5–12 years) was undertaken using McNemar's test. 1 Our findings revealed a significant association of the school?based nutrition programme with reductions in the proportion of wasting (p<0.0001; CI 12.2%–15.7%) and underweight (p<0.0001; CI 9.2%–14.5%) while no association was established for stunting (p = 0.0817; CI 0.3%–5.5%). The results support the potential for such programmes in improving the nutritional status of primary school girls in impoverished areas and gains in health and improved growth

Assessing the Migration of BPA and Phthalic Acid from Take-out Food Containers: Implications for Health and Environmental Sustainability in India

The research investigates the escalating consumption of take-out food in India and the associated health risks stemming from the extensive use of plastic packaging. Through a comprehensive nationwide online survey, the study delved into dietary preferences, frequency of take-out food consumption, delivery service timing, and the types of packaging commonly encountered by Indian consumers. To address these concerns, the research team developed an analytical method to detect Bisphenol A (BPA) and Phthalic acid migration from food-contact materials (FCMs) into various food simulants. The investigation revealed that prolonged exposure to elevated temperatures led to increased migration of BPA and Phthalic acid, particularly in polyethylene pouches using 3% acetic acid as a food simulant, with the highest concentrations observed after 45 minutes of exposure. Additionally, a microbial bioassay demonstrated the mutagenic potential of migrated plasticizers, showcasing significant effects in mammalian systems, particularly under metabolic activation. The study underscores the substantial health risks associated with plastic packaging in take-out food, emphasizing potential implications for consumer health and calling for more extensive research and considerations regarding food packaging materials

Rapid detection of in vitro antituberculous drug resistance among smear-positive respiratory samples using microcolony detection-based direct drug susceptibility testing method

Background: With the rise in multidrug-resistant tuberculosis, there is a search for newer techniques that will rapidly detect drug-resistant Mycobacterium tuberculosis. Although molecular techniques can detect resistance, culture is still considered gold standard, especially in resource-limited settings where quick, cheap, and easy techniques are needed. The aim of the study was to evaluate microcolony method thin layer agar (TLA) for quick detection of resistance against the first- and second-line antituberculous drugs in clinical isolates. This was a cross-sectional study performed at Aga Khan University Hospital.Material and Methods: A total of 87 Z-N stain smear-positive pulmonary samples were received and indirect drug susceptibility test (ID-DST) was performed using Lowenstein-Jensen and mycobacteria growth indicator tube. Direct DST was performed using TLA on 7H10 agar. TLA was observed twice weekly under microscope for 4 weeks. Sensitivity, specificity, and accuracy were calculated for TLA using indirect susceptibility method as the gold standard. Level of agreement was calculated using Kappa score.Results: TLA showed sensitivity of 89% and 95.2% for isoniazid and rifampicin, while for ethionamide, ofloxacin, and injectable aminoglycosides, it was 96.6%, 92.1%, and 100%, respectively. Specificity for the first-line drugs was \u3e95% while second-line drugs ranged from 70% to 100%. Mean time to positivity was 10.2 days by TLA as compared to 43.1 days by ID-DST.CONCLUSIONS: TLA is a quick and reliable method in identifying resistance, especially in resource-limited settings. However, additional liquid culture can be set up as backup, especially in patients on therapy to avoid false negative results