Journal of Microbiology and Related Research

  Background: Enterococci are the normal commensals of the oral cavity, gastrointestinal tract and vagina. They have emerged as serious nosocomial pathogens and its multidrug resistance as a cause for concern. This study is undertaken to isolate and speciate Enterococci from various clinical specimens by biochemical methods and to study the antibiogram. Methodology: A total of 100 isolates from the clinical specimens like urine, pus, blood and body fluids were processed in the department of Microbiology, Adichunchanagiri Institute of Medical Sciences, B.G. Nagara, for a period of one and half year. The isolates were speciated by using conventional tests and antibiotic susceptibility testing was done by Kirby Bauer disc diffusion method. Confirmation of vancomycin susceptibility was done by the Epsilometer test (E test) Results: Out of 100 Enterococcal isolates, majority were from age group of 51-60 years (24%) and male (58%). Most common species isolated was E.faecalis (74%) followed by E.faecium (26%). All isolates were sensitive to Teicoplanin and Linezolid. Majority of the isolates were resistant to Erythromycin and Ciprofloxacin. 20 isolates were intermediately sensitive to Vancomycin by the Kirby Bauer disc diffusion method. All intermediately sensitive isolates to Vancomycin were further tested by the E test and they were found to be Vancomycin sensitive. Conclusion: There is an increase in the rate of infection and antibiotic resistance in the Enterococcus species. The emergence of Vancomycin resistant Enterococci (VRE) presents a serious challenge for clinicians treating the patients and the Kirby Bauer disc diffusion method is not an accurate method for detecting the VRE. 

Keywords: Enterococcus; Speciation; VRE

  Background: Aim of the study was to know the occurrence of ESBL, AmpC and carbapenemases producers among Enterobacteriaeceae by phenotypic disc diffusion tests. Materials and methods: A total of 209 isolates belonging to the family Enterobacteriaceae obtained from different clinical samples received in the Department of Microbiology, AIMS. B.G. Ngara were included in the study. ESBL screening was done, followed by phenotypic confirmatory test by CLSI recommended combination disc method. AmpC screening and confirmation was done by phenylboronic acid test and AmpC disc test. Carbapenemase producers were screened and confirmed by CLSI recommended MHT and Remodified Hodge test for KPC detection and double disc synergy test, EDTA disc potentiation test for MBL detection. Results: The most common organism isolated was Escherichia coli 101 (48.31%) followed by Klebsiella species 52 (27.27%). Of the 209 isolates of Enterobacteriaceae 24.88%, 1.91% and 7.17% were pure ESBL, AmpC and carbapenemase producers respectively. 5.7% were ESBL and AmpC co-producers, 11.96% were ESBL and carbapenemase co-producers, 2.39% were AmpC and carbapenemase co-producers and 6.22% were combined ESBL, AmpC and carbapenemase co-producers. Conclusion: Cefotaxime/clavulanate disc potentiation test detected maximum number of ESBL producers compared to Ceftazidime/ Clavulunate. Cefoxitin–boronic acid detected maximum number of AmpC producers compared to AmpC disc test. Remodified Hodge test is better than MHT in detecting KPC producers. DDST detected more number of MBL producers compared to EDTA disc potentiation test and is a satisfactory and inexpensive method for characterizing the type of carbapenemase producers, when genotypic methods are not available.

Keywords: ESBL; AmpC; Carbapenemases; Phenotypic Methods 

  Introduction: Non-fermenters have gained significance as etiological agents of mild to potentially life threatening healthcare associated infections in recent years. Pseudomonas and Acinetobacter are amongst the commonest non fermenters causing infections in a hospital setting. The aim of this study was to find the prevalence of colistin resistance in Pseudomonas and Acinetobacter isolates from inpatients. Methodology: This retrospective study was done in our hospital which is a tertiary care centre, from April 2016 to March 2017. Identification and antibiotic susceptibility testing was done by VITEK®2 system (BioMerieux, North Carolina/USA). Antibiotic susceptibility results were interpreted according to the criteria of Clinical Laboratory Standards Institute M100S (26th edition). Patient information and microbiological profile of the organism isolated was recorded. For statistical analysis, data was described in terms of fractions and percentages and percentages were used to compare the data in two sets. Results: The most common isolates amongst non fermenters were Acinetobacter sp.(45.93%), and Pseudomonas sp. (41.62%). 92.13% of the Acinetobacter baumannii isolates were MDR and 88.76% were resistant to carbapenems. Sixtyfour percent of Acinetobacter baumannii isolates were susceptible to colistin and tigecycline only and 7.86% were resistant to colistin. In case of Pseudomonas aeruginosa, 74.67% isolates were MDR and 56% were resistant to carbapenems. Nearly 77.33% isolates were susceptible, 5.33% were intermediate 17.34% were resistant to colistin. The colistin resistant isolates of Acinetobacter baumannii and Pseudomonas aeruginosa were predominantly isolated from endotracheal aspirate (57.14%) and pus (61.53%) samples respectively. Overall 5 out of 23 (21.74%) colistin resistant isolates were resistant only to colistin and were susceptible to all other antibiotics tested. Conclusion: Increasing role of non fermenters as pathogens in the hospital settings is worrying. Judicious use of antibiotics is needed to curb the high antibiotic resistance amongst non-fermenters. 

Keywords: Colistin Resistance; Acinetobacter; Pseudomonas; Non Fermenters.

  Background and Objective: Non fermenting Gram Negative bacilli (NFGNB) are saprophytic in nature and have emerged as important healthcare associated pathogens. NFGNB group which are known to cause infections are Pseudomonas aeruginosa, Acinetobacter baumannii, Burkholderia cepacia complex and Stenotrophomonas maltophila. This study was undertaken to identify the various non fermenters isolated from patients admitted to our hospital, to assess their clinical significance and type of healthcare associated infections they caused and to know their antimicrobial sensitivity pattern. Methodology: A total of 200 non fermenter isolates from various clinical specimens received in department of Microbiology, Adichunchanagiri Institute of Medical Sciences, B.G. Nagara formed the study group. Samples were inoculated on blood agar, MacConkey agar, chocolate agar and incubated at 37°C for 18-24 hours. The clinical isolates were identified using the conventional methods and susceptibility testing was done by Kirby-Bauer disc diffusion method as per CLSI guidelines. Results: 200 NFGNB were isolated from various clinical specimens. Pseudomonas aeruginosa was the most common isolate accounting for 140 (70%) followed by Acinetobacter baumanii 32 (16%) and other nonfermenters 28 (14%). P.aeruginosa showed sensitivity to imipenem (94.2%), ceftazidime (70.7%), amikacin (69.2%), tobramycin and ticarcillin (62.8%). A.baumannii showed 100% sensitivity to imipenem and 53.1% sensitivity to amikacin and gentamicin. Conclusion: P.aeruginosa and A.baumannii were the common NFGNB isolated in our study from patients of urinary tract infections, surgical site infections, bacteremia and ventilator associated pneumonia. Thus NFGNB are emerging as important opportunistic pathogens and are resistant to commonly used antimicrobials. Therefore early diagnosis and institution of empirical therapy based on antibiotic sensitivity data of the institute would decrease mortality and improve patient management. 

Keywords: Non Fermenting Gram Negative Bacilli (NFGNB); Pseudomonas; Acinetobacter.

  Aim: The Current research was performed to find out the prevalence of bacterial agents responsible for LRTI and to find out the associated risk factors. Material and Methods: Present cross sectional study was performed in the department of Microbiology, Gujarat Adani Institute of Medical Science, Bhuj, Kutch, Gujarat. Total 200 samples including expectorated sputum and Endotracheal tube (ET) aspirates were collected from both OPD and IPD patients with clinically diagnosed Lower Respiratory Tract Infection. Expectorated sputum was collected into a sterile container with a screw cap that is tightly secured following proper instructions given to the patient. ET aspirates were transferred to a sterile screw cap container with the cap tightly secured before transport. Analysis was done using SPSS version 15 (SPSS Inc. Chicago, IL, USA) Windows software program. Results: Among the 200 samples processed, sputum and ET aspirates were 190 and 10 respectively. Out of these 38.5% samples acquiesced noteworthy development and rest of 61.5% demonstrated either no growth or modest growth which was measured as no growth. Gender and age wise allocation showed maximum number, (35.25%) of culturally confirmed LRTI cases were in the 61 – 71 years of age group. Klebsiella pneumoniae (55%) was the predominant pathogen, followed by Pseudomonas aeruginosa (20%), Acinetobacter spp (10%), Citrobacter freundii (8%), Staphylococcus aureus (2%), Streptococcus pneumoniae (3%). Conclusion: LRTIs are frequently analyzed clinically, but etiological analysis could be completed by culturing different samples from patients which will assist clinician to set up precise treatment.

Keywords: Kutch; Lower Respiratory Tract Infections; Risk Factors; Sputum