Gohar Zaman

Bacterial biofilm-based catheter-associated urinary tract infections: Causative pathogens and antibiotic resistance

HighlightsBiofilm based catheter associated urinary tract infection is now an emerging problem.Biofilm production is greatly influenced by male gender, increased duration of catheterization and by use of latex catheter.E.coli is the most common isolate of CAUTI but Enterobacter cloacae exhibit highest biofilm production.High antibiotic resistance observe in biofilm producing strains due to slow penetration, resistant phenotype and altered micro environment.Good infection control policies and antibiotic stewardship are needs of hour. Background: We sought to determine the incidence of bacterial biofilm‐based catheter‐associated urinary tract infections, identify variables affecting biofilm formation, and identify etiologic bacterial pathogens and antibiotic‐resistance patterns associated with biofilm‐based catheter‐associated urinary tract infections (CAUTIs) in our setup. Methods: Patients who developed at least 2 symptoms of urinary tract infection after at least 2 days of indwelling urinary catheters were included. Urine was collected aseptically from catheter tubing and processed per standard microbiologic practices. Bacterial pathogens were identified on the basis of gram staining, colony morphology, and biochemical reactions. The detection of the biofilm was done using the tube adherence method. Drug susceptibility testing was done using the Kirby‐Bauer disc diffusion method. Findings: Biofilm was detected in 73.4% isolates, whereas 26.6% of isolates were nonbiofilm producers. Mean duration of catheterization after which biofilm was detected was 5.01 ± 1.31 days. A latex catheter was used in 69.5% of patients, whereas a silicone catheter was used in 30.4% of patients. Escherichia coli was found to be the most common pathogen isolated (52.3%), whereas Enterobacter cloacae exhibited the highest biofilm production (87.5%) among isolated pathogens. Among biofilm producers, the highest resistance was observed with ampicillin (100%). Fosfomycin exhibited the lowest resistance (17.2%). Significant association with biofilm was detected for gender, duration of catheterization, and type of catheter. Conclusion: Biofilm‐based CAUTI is an emerging problem. E coli was the most frequent isolate. High antibiotic resistance was observed in biofilm‐producing strains. Using the variables affecting biofilm formation, tailored intervention strategies can be implemented to reduce biofilm‐based CAUTIs.

Surveillance of device-associated infections in intensive care units of a tertiary care hospital

Journal of Hospital Infection - In Press.Proof corrected by the author Available online since mercredi 9 novembre 2016

Evaluation Of Nitrate Reductase Assay For Early Detection Of Multi And Extensively Drug Resistance Tuberculosis In Our Setup

OBJECTIVE To evaluate the performance of nitrate reductase assay on smear positive pulmonary specimens for detection of multi and extensively drug resistant tuberculosis simultaneously. STUDY DESIGN Cross-sectional analytical study. PLACE AND DURATION OF STUDY Microbiology Department, Armed Forces Institute of Pathology, Rawalpindi from June to December 2016. METHODOLOGY Smear positive pulmonary samples were processed both by nitrate reductase method on Lowenstein Jenson medium and also inoculated on gold standard Bactec MGIT 960 TB system. All the specimens were first digested and decontaminated according to standard protocol before inoculation. RESULTS Out of total 76 samples, three did not give color and, therefore, were excluded from the final data analysis. Among the remaining 73 samples, mycobacterial index was: 28 specimens were having 1+ (1-9 bacilli/100 fields), 26 samples were 2+ (1-9 bacilli/ field), and 19 samples were having 3+ index (>9 bacilli/field). The respective sensitivity and specificity were 84% and 100% for isoniazid (INH); 82% and 100% for rifampin (RIF); 67% and 100% for amikacin (AK); and both 100% for ofloxacin (OFX). Overall agreement in case of INH, RIF, AK, and OFX was 94.5%, 97.2%, 98.6% and100%, respectively. Overall average agreement was 97.5%. CONCLUSION Nitrate reductase assay is a reliable, low cost and accurate method that can be used for early for diagnosis of multi and extensively drug resistant tuberculosis.

Cerebral Abscess Caused By Novel Species: Streptococcus Pluranimalium

Streptococcus pluranimalium, a gram-positive aerobic coccus, has been isolated primarily from several farm animals. The pathogenicity of this species is not well characterised either in animals or humans. As per the literature, cases of S. pluranimalium infection in humans have been reported only a handful of times. We report the case of cerebral abscess caused by S. pluranimalium in a patient who presented with weakness and confusion. The diagnosis of cerebral abscess was made on imaging supported by microbiological culture. Burr hole procedure for abscess drainage followed by an antibiotic regimen based on culture and sensitivity results contributed to a successful outcome. The bacteria were identified by analytical profile index for Streptococci (API Strep) and VITEK 2 gram-positive cocci panel. The case was successfully treated with vancomycin.

Direct Susceptibility Testing On Mgit 960 Tb System: A Rapid Method For Detection Of Drug Resistant Tuberculosis

OBJECTIVE To evaluate direct drug susceptibility testing on MGIT 960 system for detection of multidrug resistant tuberculosis from smear positive pulmonary specimens. STUDY DESIGN Cross-sectional analytical study. PLACE AND DURATION OF STUDY Microbiology Department, Armed Forces Institute of Pathology, Rawalpindi, from July 2016 to September 2017. METHODOLOGY Smear positive specimens were pretreated according to guidelines and then tested on MGIT 960 TB system for direct drug susceptibility testing (DST) of isoniazid and rifampin. Samples were also processed by gold standard indirect method, which comprises culture and then DST from positive growth by MGIT 960 TB system. RESULTS Out of 108 specimens, 95 (88%) DST results were reportable. Out of 95 reportable specimens, 17 isolates were resistant to both isoniazid (INH) and rifampin (RIF) by direct DST. The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy for INH were 92%, 93%, 82%, 97% and 92.6%, respectively; and 95%, 96%, 86.3%, 98.6% and 95.7%, respectively for RIF. Average time to report DST by indirect method was 23.6 ±3.9 days, while it was 11.4 ±2.7 days for the direct method. CONCLUSION Direct susceptibility testing on MGIT 960 system showed very good agreement when compared with indirect method. Time saving is crucial factor in initiation of early effective therapy, especially in drug resistant cases. Further studies on large scale are required for more accurate evaluation of this method.

Native valve dual pathogen endocarditis caused by Burkholderia cepacia and Aspergillus flavus – a case report

Introduction Infective endocarditis (IE) is an important clinical condition with significant morbidity and mortality among the affected population. A single etiological agent is identifiable in more than 90 % of the cases, however, polymicrobial endocarditis (PE) is a rare find, with a poor clinical outcome. Here we report a case of native valve dual pathogen endocarditis caused by Burkholderia cepacia and Aspergillus flavus in an immunocompetent individual. It is among unique occurrences of simultaneous bacterial and fungal etiology in IE. Case presentation A 30-year-old male was admitted to a cardiology institute with complaints of low grade intermittent fever and progressive shortness of breath for last two months. He was a known case of rheumatic heart disease and had suffered an episode of IE three years ago. On the basis of clinical presentation and the results of radiological investigations, a diagnosis of infective endocarditis was made. Paired blood samples for culture and sensitivity, sampled before the commencement of antimicrobial therapy, yielded growth of Burkholderia cepacia which was highly drug resistant. Sensitivity results-directed therapy consisting of tablet Trimethoprim–Sulfamethoxazole, two double-strength tablets 12 hourly, and Meropenem, 1 g IV every 8 h, was commenced. Despite mild relief of fever intensity, overall clinical condition did not improve and double valve replacement therapy was carried out. Excised valves were sent for microbiological analysis. Burkholderia cepacia was grown on tissue culture with a similar antibiogram to that previously reported from the blood culture of this patient. Direct microscopy of section of valvular tissue with 10 % KOH revealed abundant fungal hyphae. Patient serum galactomannan antigen assay was also positive. Histopathological examination of vegetations also revealed hyphae typical of species of the genus Aspergillus. The patient was successfully treated with meropenem, trimethoprim–sulfamethoxazole and voriconazole. Conclusion The hallmark of successful treatment in this case was exact identification of pathogens, antibiogram-directed therapy and good liaison between laboratory experts and treating clinicians.

Necrotizing Fasciitis Due to Rhizopus in Blast Injury Wound - An UnusualLife Threatening Situation

Zygomycosis or mucormycosis is an extremely uncommon infection with a high mortality rate. The rate of zygomycosis over the last decade has increased tremendously, specifically in health care facilities for immunocompromised patients. Mucormycosis is an atypical but fatal fungal infection that may lead to death in those who do not receive timely treatment. Wound contamination with organic matter can lead to skin and soft tissue fungal infections, notably mucormycosis. We report a case who presented with post-surgical wound infection of Rhizopus arrhizus after sufferin g a blast injury.

Pattern of Gram-negative Blood Stream Infections and their Antibiotic Susceptibility Profiles in a Neonatal Intensive Care Unit

Journal of Hospital Infection - In Press.Proof corrected by the author Available online since vendredi 22 decembre 2017

Cornyebacterium striatum : an Emerging Bug

The increasing prevalence of chronic infections, with frequent exposure to broad-spectrum antibiotics for repeated and prolonged hospitalizations, favors the emergence of nosocomial infection by Gram-positive bacteria, such as outbreaks of Corynebacterium striatum. Cornyebacteria are gram-positive non spore forming rods. Many species are part of the normal skin and mucosal flora of humans. The clinical significance of C. striatum has recently been established. C. striatum has recently been reported to cause a variety of infections including pneumonia, endocarditis, septic arthritis, cerebrospinal fluid infection, surgical site infections and septicemia. In this study, describing three cases of Corynebacterium striatum that are attributed to health care associated infections and presented as post-surgical wound infection and hospital acquired pneumonia. The three cases include a case of a 68 years old lady who was readmitted with fever, pain and purulent discharge from surgical wound of the lower back, a 57 years old man who was readmitted 2 months after a road traffic accident with surgical wound infection of forearm and a 25 years old man on respiratory support after a head injury with ventilator associated pneumonia.