CLINICOMICROBIOLOGICAL STUDY OF INFECTIONS CAUSED BY ACINETOBACTER SPECIES

Objectives: To study the rate of isolation of Acinetobacter species, its antibiogram and associated risk factors.Methods: Retrospective time bound study for 6 months. The study included 191 consecutive clinical significant isolates of Acinetobacter speciesisolated from various specimens. The identification and antibiotic susceptibility testing by modified Kirby Bauer and Vitek Compact system 2.Results: Maximum isolation of Acinetobacter species was from suction tip (31.94%), sputum (19.89%), urine (14.66%), blood (10.47%), and others.The species was most sensitive to colistin (97.87%) and polymyxin B (99.43%). The species was most resistant to imipenem (72.62%) and gentamicin(66.66%). The common risk factors were invasive procedure, duration of intensive care unit stay, and malignancies.Conclusion: Acinetobacter has emerged as a major nosocomial pathogen. Antibiotic resistance is on rise. Proper antibiotic stewardship is requiredto curtail antibiotic resistance in this region.Keywords: Acinetobacter spp., Antibiotic resistance, Health care associated pathogenÂ

CARBAPENEM-RESISTANT ENTEROBACTERIACEAE: NEW MENACE TO OUR ANTIBIOTIC ARMAMENTARIUM!

  Objective: To study the risk factors, clinical characteristics, and outcome in patients with infections due to CRE infections.Methods: Retrospective study was carried out in a microbiology laboratory for 6 months. 152 CRE isolates identified by the Vitek 2 compact system were included in the study. The risk factors, antibiotic treatment and clinical outcome were studied from the case sheets, Chi-square test was used for statistical analysis.Results: Of the 2520 positive cultures for Enterobacteriaceae, isolation rate of CRE was 152 (6%). 76 (50%) belonged to exudates, 22 (14.1%) blood culture, 90 (59.2%) urine. The common infection was UTI. The risk factors were prior exposure to antimicrobials, admission to intensive care unit, indwelling devices and prior hospitalization. The effective antibiotic was colistin, polymyxin B, tigecycline, cefoperazone-sulbactum, piperacillin-tazobactum. The mortality was 19.7%.Conclusion: We have demonstrated the value of understanding local epidemiology to help modify our risk-based screening as a strategy to limit the spread of CRE

XPERT MYCOBACTERIUM TUBERCULOSIS/RIFAMPICIN ASSAY: A BOON IN TUBERCULOSIS DIAGNOSTICS

Objectives: Mycobacterium tuberculosis (MTB) remains one of the most significant causes of mortality and morbidity in developing countriesespecially India. India has the highest burden of TB, with an estimated incidence figure of 2.1 million cases out of the 9 million cases of TB globally.Diagnosis of TB relies on conventional microscopy and culture with drawbacks related to sensitivity, specificity, turn around time (TAT). The aim ofthis study was to evaluate the performance of Xpert MTB/rifampicin (RIF) assay (GX) for MTB detection in pulmonary and extrapulmonary clinicalsamples.Methods: A total of 209 clinical specimens (182: pulmonary and 27: extrapulmonary) were processed using auramine smear, culture by mycobacteria growth indicator tube and GenXpert.Results: The sensitivity of GenXpert was 62.63% for pulmonary and 55% for extrapulmonary samples. The sensitivity and specificity of GX were100% for the smear positive cases. The sensitivity, specificity, positive predictive value, and negative predictive value of the GX for smear negativecases were 67.8%, 97.5%, 90.4%, and 89.6%, respectively. RIF resistance was detected in 3.8% the samples.Conclusion: GenXpert, with short TAT, high sensitivity, specificity and less technical expertise required is a promising tool in TB diagnostics for thefuture.Keywords: GenXpert, Tuberculosis diagnosis, Molecular method, Rifampicin resistance

Characterization of virulence factors and antibiotic resistance pattern of uropathogenic Escherichia coli strains in a tertiary care center [version 2; peer review: 2 approved]

Background: Urinary tract infection(UTI) is one of the commonly prevalent bacterial infection in humans.The uropathogenic E. coli (UPEC) expresses a range of virulence factors that contribute to their pathogenicity. The emergence of multidrug resistance (MDR)-associated UTI is increasing.This study monitors the distribution of virulence factors among UPEC strains to note the antibiogram, outcome and type of associated UTI. Methods:A prospective cross-sectional time-bound study of six months was done on clinically significant urinary isolates of Escherichia coli. Detection of haemolysin production and serum resistance was done by phenotypic methods. Genotypic characterization of the virulence genes (papC, iutA, hlyA, cnf1) was done by multiplex PCR. Demographic data, clinical history, antibiogram and type of UTI was collected from clinical case records. Results:75 E.coli isolates from patients with suspected UTIs were included. Females had a higher preponderance of UTI (66.7%). 93% of patients were adults and the remaining 7% were from paediatrics.  24 (32%) isolates showed haemolysis by plate haemolysis and all isolates were serum-resistant. Out of 75 isolates, 65 were positive for at least one of four targeted genes, while remaining ten isolates were negative for all four genes.Multidrug resistance was found in 40 (53.3%) isolates. 97.4% of the UTI cases had a favourable clinical outcome at discharge. Mortality due to urosepsis was 2.6%. Conclusion:Association of hemolysin production with resistance to imipenem and norfloxacin in UPEC strains was significant.Presence of hlyA gene is positively associated with ceftazidime resistance. Nitrofurantoin, piperacillin, tazobactam, and cefaperazone sulbactam are possible candidates for empirical therapy of UTIs. Drugs like aminoglycosides, carbapenems and fosfomycin may be used as reserve drugs in the treatment of MDR-UTI.However, inappropriate usage can increase antibiotic resistance. Hence proper selection of antibiotics in hospitals taking into account the local antibiogram is needed to reduce the emergence of antibiotic resistance

Bacteriologic Profile and Antibiogram of Blood Culture Isolates in a Pediatric Care Unit

Background / Aims : Septicemia is one of the important causes of mortality and morbidity in neonates and children. Blood culture is the gold standard for the diagnosis. Emergence of multidrug resistant bacterial strains is a major problem in the management of sepsis. Present study was undertaken to identify the common bacterial pathogens associated with pediatric sepsis and to determine their antibiotic susceptibility pattern. Materials and Methods : Blood cultures from 185 suspected cases of sepsis were examined. The growths from the subcultures were identified by conventional biochemical tests. Antibiotic susceptibility testing was performed by modified Kirby-Bauer disk diffusion method and drug resistant strains in primary screening were further processed for extended spectrum beta lactamases (ESBL) and methicillin resistant Staphylococcus aureus (MRSA) status by combination disk method (ESBL) and oxacillin disk diffusion method (MRSA). Results : Out of the 185 cultures obtained from suspected cases, 81 (44%) were culture positive. Fifty-two (35%) of the culture isolates were Gram negative bacilli. Twenty-eight (64%) of the isolates were Gram positive cocci. One case was of mixed infection. The prevalence of MRSA in 41 strains of S. aureus was found to be 29% (12 strains). The overall prevalence of ESBL producers among 28 Gram negative bacterial isolates was found to be 32% (9 strains). Conclusion : This study stresses the need for the continuous screening and surveillance for antibiotic resistance in pediatric care unit

Comparison of the Antimicrobial Efficacy of Various Contact Lens Solutions to Inhibit the Growth of Pseudomonas aeruginosa and Staphylococcus aureus

Soft contact lenses provide perfect conditions for the breeding of pathogens. The study is a prospective, experimental study, conducted to know the antimicrobial ability of multipurpose contact lens solution against standard strains of Staphylococcus aureus and Pseudomonas aeruginosa by the stand-alone test. The test method is based on the procedures in the ISO 14729 standard primary stand-alone test. Three multipurpose contact lens care solutions commercially available in Mangalore markets, namely, Biotrue (Bausch & Lomb), Opti-Free Replenish (Alcon), and Aquasoft (Stericon Pharma), were tested for its antimicrobial effect in the microbiology lab at Kasturba Medical College, Mangalore. According to this study, the solutions named “Biotrue” and “Aquasoft” met the primary stand-alone and reached the 3log reduction and 5log reduction criteria in the manufacturer recommended time, respectively. No conclusion could be drawn for Opti-Free Replenish since the minimum recommended disinfection time was overnight, whereas it was noted for 6 hr only, and it should have been experimented further. The effectiveness of multipurpose solutions varies against different bacterial species. We have observed that the antimicrobial activity of different solutions varies with respect to time of incubation, and also there was a marked difference in the activity of some solutions against S. aureus and P. aeruginosa. So, it is necessary for the contact lens users to store their lenses in solutions for longer duration of hours. It is also recommended to use solutions that clear the ISO 14729 standards for better health conditions of the eye

Bacterial Infection among Cancer Patients: Analysis of Isolates and Antibiotic Sensitivity Pattern

Introduction. Cancer patients being immunosuppressed are vulnerable to develop infections. Knowledge of the changing epidemiology of infections has a pivotal role in its management. Aims and Objectives. The study is undertaken to assess the types of bacterial infections in cancer patients undergoing anticancer treatment, the associated bacterial pathogens, and their antibiotic sensitivity patterns. Materials and Methods. A retrospective surveillance study was undertaken in our center. Positive culture reports and other clinical details of cancer patients diagnosed with infection during a stay in the tertiary care center from 1st January 2015 to 31st December 2016 were analysed by descriptive statistical methods chi-square test and odds ratio to study the association. Results. Out of 638 cancer patients diagnosed with infections in the 2-year period, 140 patients had positive cultures, representing 272 specimens and 306 isolates. Common specimens sent for culture were blood sputum, urine, and pus. 214 isolates (69.9%) were gram-negative bacilli, and 92 (30.1%) were gram-positive cocci. The most common isolates were Klebsiella spp. (18.30%), Pseudomonas spp. (17.65%), and Escherichia coli (14.71%) followed by Staphylococcus aureus (13.72%). Among the gram-negative organisms, the antibiotic resistance rates reported to fluoroquinolones, aminoglycosides, and third-generation cephalosporins were 45.13%, 39.20%, and 48.58%, respectively. 26.92% of the organisms are resistant to all three antibiotics. 50.4% of Klebsiella spp. and Escherichia coli were ESBL producers. Gram-negative organisms showed 11.63% resistance to β-lactam/β-lactamase inhibitor combination, and 22.22% of gram-negative organisms are resistant to carbapenems. 50% of the Staphylococcus spp. were methicillin resistant, but all were sensitive to vancomycin. Conclusion. The surge in the number of gram-negative infections emphasizes the need for broad-spectrum empirical therapy targeting the same. Rate of resistance of the isolated gram-negative organisms to the routinely used empirical therapy is alarming. Prudent use of antibiotics, based on culture reports wherever possible, is of utmost importance to save the lives of infected patients and prevent further development of antibiotic resistance

Bacteriological Assessment of Bottled Drinking Water Available at Major Transit Places in Mangalore City of South India

Introduction. Safe drinking water is essential for human life. It is generally considered that bottled water is safe for usage by people. For long-distance travelers, it serves as the only source of reliable drinking water. But, several studies have reported that bottled water does not always meet the acceptability standards. Objectives. To assess the bacteriological and physical quality of bottled water marketed in major transit areas and to check its compliance with national standards. Methods. The investigating team visited retail shops at three main transit sites for long-distance travelers in Mangalore city. A total of 24 water bottles of 12 brands were randomly selected. The analysis of total viable count (TVC) was done to assess the bacteriological quality of samples. Results. In 3(12.5%) samples, all of which were of local brands, batch number, the period of manufacture, and the period of expiry were not mentioned. Odor and floating bodies were present in one sample each. Five (20.8%) water bottles had been enriched with minerals. Ozone treatment was the most commonly 22(91.7%) used method for disinfection of water. In only 15(62.5%) samples, the bacterial contamination was within acceptable limits certified for drinking purposes. Water samples manufactured by multinational companies (p=0.018), those with batch number mentioned (p=0.042), the best period of manufacture (p=0.036), and long expiry dates (p=0.028) were acceptable for usage. Conclusion. Surveillance of bottled water manufacturing industries in the settings on a regular basis needs to be done by regulatory agencies. These measures will ensure safe and wholesome bottled water for public usage