scholarly journals Antimicrobial Susceptibility Pattern of Enterococcus Species Isolated from Various Clinical Specimens in a Tertiary Care Hospital, Kathmandu, Nepal

2018 ◽  
Vol 20 (4) ◽  
pp. 173-177
Author(s):  
Ram Prasad Adhikari ◽  
S. Shrestha ◽  
A. Barakoti ◽  
J.R. Rai ◽  
R. Amatya
Keyword(s):  
Antimicrobial Susceptibility ◽  
Diffusion Method ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Disc Diffusion ◽  
Clinical Specimens ◽  
Enterococcus Spp ◽  
Gentamicin Resistance ◽  
Agar Dilution ◽  
High Level

Resistance to vancomycin and high level aminoglycosides are common among Enterococcus spp. and are being increasingly reported from different parts of the world. These resistance phenomena in enterococci have limited the therapeutic options to treat the infections caused by them. The objective of our study was to determine the antimicrobial resistance patterns of Enterococcus spp. (n=60) isolated over a year from clinical specimens received from patients visiting Nepal Medical College Teaching Hospital, Kathmandu, Nepal. All enterococci were subjected to antimicrobial susceptibility testing, high level gentamicin resistance testing by disc diffusion method and minimum inhibitory concentration of vancomycin by agar dilution method. Prevalence of high level gentamicin resistance among enterococci was 55%. None of the isolates were resistant to vancomycin by both disc diffusion and agar dilution method. However 8.3% of them were intermediate to vancomycin. All of these vancomycin intermediate isolates were from samples from hospital admitted patients and resistant to ampicillin, ciprofloxacin, erythromycin and high level gentamicin. Present findings were suggestive of possible emergence of vancomycin resistant enterococci in the hospital if immediate and adequate control measures are not implemented.

scholarly journals Comparison of the Antimicrobial Susceptibility Results of Bacteroides fragilis Group Isolates Determined by Agar Dilution and the Tentative EUCAST Disk Diffusion Method

2021 ◽  
Author(s):  
Semra Eminoğlu ◽  
Bermal Tekeş ◽  
Elvan Sayın ◽  
Nurver Ülger Toprak
Keyword(s):  
Antimicrobial Susceptibility ◽  
Bacteroides Fragilis ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Disc Diffusion ◽  
Disc Diffusion Method ◽  
Bacteroides Fragilis Group ◽  
Agar Dilution

Objective: In this study it was aimed to determine the antimicrobial susceptibility of Bacteroides fragilis group (BFG) bacteria using recently developed European Committee on Antimicrobial Susceptibility Testing (EUCAST) disc diffusion method and agar dilution method recommended by Clinical Laboratory Standart Institude (CLSI) for anaerobes and to investigate the agreement of the results of two tests. Method: The antimicrobial susceptibilities of a total of 56 BFG strains isolated from clinical samples and identified by MALDI-TOF MS analysis between January 2017 and December 2018, were tested to ampicillin, ampicillin/sulbactam, cefoxitin, imipenem, clindamycin, tigecycline, moxifloxacin and metronidazole MICs were determined by agar dilution method using sheep blood supplemented Brucella agar and disk diffusion test using host blood supplemented Fastidius Anaerobic Agar (FAA). Results: Six different BFG species consisting mostly strains of Bacteroides fragilis (n=34, 61%) and Bacteroides thetaiotaomicron (n=11, 20%) isolated from various clinical samples such as intraabdominal abscess (n= 24), blood (n=10) and tissue biopsy samples (n=11).were identified. Imipenem and metronidazole were the most effective antimicrobials with 98.2% susceptibility rates, followed by tigecycline, ampicillin/sulbactam, moxifloxacin and clindamycin with susceptibility rates of 89.3%, 66.1%, 57.1% and 46.4%, respectively. Most concordant results were obtained with metronidazole (100%), imipenem (89.8%) and tigecycline (89.8%). Acceptable compliance rates were not found for other antimicrobials. Conclusion: We can say that disc diffusion method is a fast, easy-to-apply, and reliable method used in clinical microbiology laboratories to determine the susceptibility of BFG bacteria to metronidazole, imipenem and tigecycline. However, to evolve a standard method especially for other antimicrobials, the experimental conditions should be optimized with studies dome with greater number of isolates.

scholarly journals Characterization of Clinical Isolates ofEnterococciwith Special Reference to Glycopeptide Susceptibility at a Tertiary Care Center of Eastern Nepal

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Aasish Karna ◽  
Ratna Baral ◽  
Basudha Khanal
Keyword(s):  
Multidrug Resistance ◽  
Minimum Inhibitory Concentration ◽  
Antimicrobial Susceptibility ◽  
Inhibitory Concentration ◽  
Tertiary Care ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Disc Diffusion ◽  
Diffusion Technique ◽  
Agar Dilution

Background. Enterococci, once considered as a harmless commensal of intestine, have now emerged as medically important pathogens and are associated with both community-acquired and nosocomial infections. They bear the potential to exhibit resistance against all commonly used antibiotics either by inherent or acquired mechanism, posing a therapeutic challenge.Objectives. This study aimed to characterize enterococci up to the species level and study their antibiogram with special regard to vancomycin.Methods. A descriptive cross-sectional study was conducted in the Department of Microbiology, B.P. Koirala Institute of Health Sciences, Dharan, Nepal, from February to May 2017. A total of 91 enterococcal isolates recovered from clinical specimens were investigated in this study. Their identification and speciation were done according to standard microbiological guidelines. Kirby–Bauer disc diffusion technique was used to study antimicrobial susceptibility pattern, whereas minimum inhibitory concentration of vancomycin was determined by the agar dilution method, with reference to Clinical and Laboratory Standards Institute guidelines.Results. Seven different species of enterococci were isolated,E. faecalisandE. faeciumaccounting about 45% each. The other species encountered wereE.avium,E.cecorum,E.dispar,E.durans, andE.raffinosus. Highest proportion of antimicrobial susceptibility was recorded for linezolid (97.8%), followed by teicoplanin (95.6%) and high-level gentamicin (81.3%). Sensitivity to vancomycin was seen in 79.1% isolates. Likewise, 82.1% of urinary strains were susceptible to nitrofurantoin. A total of 4 disparities were observed between the disc diffusion technique and agar dilution method in determining vancomycin resistance. Multidrug resistance was observed in 31.9% isolates. The overall prevalence of vancomycin-resistant enterococci based on the standard minimum inhibitory concentration method was 25.3%.Conclusions.Enterococcus faecalisandE. faeciumwere the predominant species in causing enterococcal infections. The alarming rise in prevalence of vancomycin and multidrug resistance strains warrants immediate, adequate, and efficient surveillance program to prevent and control its spread.

scholarly journals In Vitro Antimicrobial Activity of Tigecycline

2015 ◽  
Vol 13 (2) ◽  
pp. 35-38
Author(s):  
Sabita Bhatta ◽  
Babli Basu ◽  
Chandrasekhar Narharrao Chaudhary ◽  
Ashok Kumar Praharaj
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Susceptibility ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Diffusion Method ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Klebsiella Pneumonia ◽  
Methicillin Resistant ◽  
Agar Dilution ◽  
Vancomycin Resistant

Introduction: Tigecycline is a novel glycylcycline  derivative of the tetracycline with activity against a wide range of  organisms including Methicillin resistant Staphylococcus aureus, Vancomycin  resistant  Enterococcus , Extended spectrum beta lactamase   producing  (Escherichia coli , Klebsiella  pneumonia)  and Acinetobacter species.  The aim of the study was to assess effectiveness of the drug against methicillin resistant Staphylococcus aureus (MRSA), vancomycin resistant enterococci (VRE), ESBL producers and carbapenem resistant Acinetobacter baumannii and to compare the efficacy of different methods of antimicrobial susceptibility testing for Tigecycline.Methods: A total of 250 clinical isolates were processed and identified by conventional methods. In all the 250 isolates, antimicrobial susceptibility was carried out by disc diffusion method , Minimum inhibitory test by agar dilution method (MIC) and in 30 isolates of A baumannii  MIC was also done by E test.Results: Out of 250 isolates, 236 isolates were sensitive to tigecycline by agar dilution method while only 159 were sensitive by disk diffusion method.Conclusion: Marked discordance was observed between the results of two different methods (DDT & Agar dilution method) for E coli, Klebsiella spp and A baumannii, where significant number of isolates were resistant to tigecycline by DDT as compared to AD method. But results of MIC by agar dilution method & E test were in concordance for A. baumannii.

scholarly journals Antimicrobial susceptibility profiles of thermophilic campylobacters isolated from patients in the town of Nis

2009 ◽  
Vol 66 (7) ◽  
pp. 522-526 ◽  
Author(s):  
Biljana Miljkovic-Selimovic ◽  
Tatjana Babic ◽  
Branislava Kocic ◽  
Ljiljana Ristic
Keyword(s):  
Nalidixic Acid ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Thermophilic Campylobacter ◽  
Agar Dilution ◽  
High Level ◽  
Susceptibility Profiles ◽  
The Town

Background/Aim. In some clinical forms of human Campylobacter infections, such as prolonged diarrhea or associated with postinfections sequels, antibacterial treatment is necessary. The aim of the present study was to evaluate the antimicrobial susceptibility of thermophilic Campylobacter strains isolated from patients with diarrhea, as well as from patients with diarrhea followed by postinfections sequels, to drugs used in the therapy of enterocolitis, and to nalidixic acid used in laboratory identification and differentiation of thermophilic Campylobacter spp. Methods. We studied the antimicrobial susceptibility profiles of 131 Campylobacter strains isolated from patients with diarrhea (122 strains), diarrhea associated with rheumatic disorders (8 strains), and one strain isolated from a patient with Guillain-Barr? Syndrome following Campylobacter enterocolitis. Susceptibility testing to erythromycin, gentamicin, tetracycline, chloramphenicol, ciprofloxacin and nalidixic acid was performed by the agar dilution method. Results. In the strains we investigated, resistance to gentamicin and chloramphenicol was not recorded, whereas a low rate of strains resistant to erythromycin (2.4%), a higher prevalence of strains resistant to tetracycline (9.9%), and a high level of resistance to ciprofloxacin (29.8%) and nalidixic acid (33.3%) were registered. All strains resistant to nalidixic acid were also resistant to ciprofloxacin. In addition, there was no difference in the occurrence of resistance between strains isolated from patients with diarrhea as compared to those isolated from patients with diarrhea followed by postinfection disorders. Conclusion. The fact that the most of Campylobacter strains were sensitive to erythromycin and all to gentamicin, makes erythromycin an antibiotic of choice in the treatment of Campylobacter diarrhea and gentamicin when parenteral therapy should be administered. Resistance to tetracycline and, especially, ciprofloxacin, necessitates antibiotic susceptibility testing.

scholarly journals Fosfomycin Sensitivity Pattern among Uropathogens Isolated from Patients Visiting Day Care Facility of Sushila Tiwari Hospital in Kumaun Region, Uttarakhand, India

2021 ◽  
Author(s):  
Shraddha Sharma ◽  
Pankaj Kumar Verma ◽  
Vinita Rawat ◽  
Umesh, Vikrant Negi
Keyword(s):  
Day Care ◽  
Pathogenic Bacteria ◽  
Urine Samples ◽  
Diffusion Method ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Disc Diffusion ◽  
Sensitivity Pattern ◽  
Agar Dilution ◽  
Tract Infections

Introduction: Urinary Tract Infections (UTI) are one of the most common infections responsible for antibiotic resistance. There are limited antibiotics options for treating the cases due to Multi Drug Resistant (MDR) bacteria. Fosfomycin is being used for treating UTIs and has shown promising results even against MDR pathogens. Aim: To determine the fosfomycin sensitivity pattern along with Minimum Inhibitory Concentration (MIC) against uropathogens by agar dilution method. Materials and Methods: The present cross-sectional study was conducted in the Department of Microbiology, Government Medical College Haldwani, Uttarakhand, India, between August 2017 to September 2019. Clean catch, mid stream urine samples were inoculated on Cystine Lactose Electrolyte Deficient (CLED) agar and incubated. The significant growths of pathogenic bacteria were subjected to antibiotic susceptibility testing. Fosfomycin (200 μg) disc was used in Kirby-Bauer disc diffusion testing. Fosfomycin trometamol MIC was determined by agar dilution method as per Clinical and Laboratory Standards Institute (CLSI) guidelines. The data collected in the study were analysed by using Statistical Package for the Social Science (SPSS) software version 20.0. Results: Significant growth of pathogenic bacteria was observed in 365 out of total 2725 urine samples. E.coli (72.32%) was the leading isolate followed by Enterococcusspecies (10.41%). Fosfomycin was recorded as the most active antibiotic against all the bacterial pathogen with 85-100% susceptibility except Proteus species (40%) in disc diffusion method. The MIC of fosfomycin was recorded between 4-64 against most of the isolates by agar dilution method. Conclusion: Fosfomycin is the most active antibiotic against all the uropathogens in the study setup and can be included in empirical treatment of day care patients along with nitrofurantoin.

Antimicrobial susceptibility of Neisseria gonorrhoeae strains isolated in Nuuk, Greenland during 1998–1999

2002 ◽  
Vol 13 (12) ◽  
pp. 826-828 ◽  
Author(s):  
D Dragsted ◽  
P Poulsen ◽  
C Nørgaard ◽  
I Lind
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Diffusion Method ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Reference Laboratory ◽  
Disc Diffusion ◽  
First Line ◽  
Disc Diffusion Method ◽  
Agar Dilution ◽  
Line Drug

Sixty-one gonococcal strains isolated in Greenland during 1998-1999 were tested locally for susceptibility to penicillin and ciprofloxacin by a disc diffusion method (Rosco®) and at the reference laboratory in Copenhagen by the agar dilution method and the E-test®, showed that more than 60% of the strains were less susceptible or resistant to penicillin (minimum inhibitory concentration [MIC] ≥ 0.25 mg/L), indicating that penicillin should not be used as a first line drug for the treatment of gonorrhoea in Greenland. The Rosco® disc diffusion method only identified 8% of strains as less susceptible to penicillin. Ciprofloxacin can still be used as a first line drug for treatment of gonorrhoea in Greenland since decreased susceptibility was only seen in one imported strain. However, the decreased susceptibility in this strain was not identified by the Rosco® disc diffusion test, therefore the future local surveillance of antibiotic resistance in Neisseria gonorrhoeae will be based on MIC determinations.

scholarly journals Prevalence and characterization of extended spectrum beta-lactamase-producing Enterobacter cloacae strains in Algeria

2013 ◽  
Vol 7 (11) ◽  
pp. 804-811 ◽  
Author(s):  
Sabrina Nedjai ◽  
Abouddihaj Barguigua ◽  
Nassima Djahmi ◽  
Loubna Jamali ◽  
Khalid Zerouali ◽  
...  
Keyword(s):  
Enterobacter Cloacae ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Extended Spectrum Beta Lactamase ◽  
Agar Dilution ◽  
Synergy Test ◽  
High Level ◽  
Genomic Typing ◽  
Microbiological Data

Introduction: Expended spectrum β-lactamase (ESBL)-producing Enterobacter cloacae is an important nosocomial pathogen. In this study, the prevalence and the molecular epidemiology of ESBL producing E. cloacae strains isolated from various hospitals in Annaba, Algeria were investigated. Methodology: The study involved 63 isolates of E. cloacae obtained during 2009 at the four hospitals in Annaba. The detection of ESBL was performed using the double-disk synergy test and the combined disk test. Minimum inhibitory concentrations (MICs) were determined using the agar dilution method. The presence of blaCTX-M, blaSHV, blaTEM, and blaDHA β-lactamase genes was evaluated by PCR, and genomic typing was determined by pulsed-field gel electrophoresis (PFGE) analysis. The clinical and microbiological data were entered into the EpiI Info database. Results: Thirty isolates (47.6%) had an ESBL phenotype. BlaCTX-M group1 (76%); blaTEM (70%) were the most prevalent, followed by blaDHA (16.6%) and blaSHV (10%). Eighteen strains expressed at least two bla genes. MICs revealed a high level of resistance to cefotaxime, ceftazidime, and cefepime.  PFGE revealed an epidemic clonal dissemination of these isolates. Various risk factors associated with the occurrence of ESBL-producing E. cloacae were detected. Conclusions: A higher frequency of ESBL-producing isolates and a diversity of β-lactamases were detected among ESBL-producing E. cloacae; these resulted from an epidemic clonal dissemination and high transference of ESBL genes between bacteria in hospital settings. Strict measures will be required to control the further spread of these pathogens in hospital settings.

scholarly journals Comparison of methods for the determination of antimicrobial resistance in Campylobacter spp. human and the food chain isolates

2008 ◽  
Vol 52 (No. 4) ◽  
pp. 169-174
Author(s):  
M. Holasova ◽  
R. Karpiskova ◽  
S. Karpiskova ◽  
V. Babak ◽  
J. Schlegelova
Keyword(s):  
Nalidixic Acid ◽  
Antimicrobial Agents ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Disk Diffusion Method ◽  
Microdilution Method ◽  
Study Results ◽  
Agar Dilution

With a microdilution method, using the commercial diagnostic test Sensititre Susceptibility Plates for Campylobacter MIC (Trek Diagnostic Systems, Cleveland, OH, USA), disk diffusion and agar dilution method, resistance to six antimicrobial agents were examined in a reference strain <i>Campylobacter jejuni</i> ATCC 33560 and 73 thermo-tolerant isolates of <i>Campylobacter</i> spp. For the microdilution method and all tested antimicrobial agents, our determined values of microbiological breakpoints of resistant strains were suggested as the minimum inhibitory concentration (MIC<sub>R</sub>) for ciprofloxacin &ge; 0.5, erythromycin &ge; 4, gentamicin &ge; 4, nalidixic acid &ge; 32 and tetracycline &ge; 4 &mu;g/ml. On the basis of our study results, strains resistant to clindamycin were MIC<sub>R</sub> &ge; 2 &mu;g/ml for the dilution methods and a zone diameter R ≤ 16 mm for the disk diffusion method. Comparison of the results of the resistance examination, a microdilution method and disk diffusion method with the reference agar dilution method, showed that all compared methods yielded identical results with the exception of the resistance determination in erythromycin and nalidixic acid. The errors were mostly the result of the interpretation criteria for MIC<sub>R</sub> of agar dilution method and different conditions of cultivation used. However, the compared methods, provide results comparable with the reference method having greater convenience of measurement.

scholarly journals Plasmid mediated colistin resistant mcr-1 and co-existence of OXA-48 among Escherichia coli from clinical and poultry isolates: first report from Nepal

Gut Pathogens ◽  
2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Bijaya Muktan ◽  
Upendra Thapa Shrestha ◽  
Binod Dhungel ◽  
Bagish Chandra Mishra ◽  
Nabaraj Shrestha ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Resistance Gene ◽  
Diffusion Method ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Colistin Resistance ◽  
Clinical Specimens ◽  
E Coli ◽  
Resistant Genes ◽  
Rectal Swabs

Abstract Background Plasmid-mediated resistance to the last-resort drugs: carbapenems and colistin is an emerging public health threat. The studies on the prevalence and co-expression of resistant genes among livestock and human pathogens are rare in Nepal. This is the first study in Nepal exploring the prevalence and co-existence of colistin resistance gene, mcr-1 along with carbapenemase resistance gene, OXA-48 in Escherichia coli isolated from poultry and clinical specimens. Methods A total of 240 rectal swabs from chickens of five different poultry farms of Kathmandu valley and 705 mid-stream urine samples from human subjects attending Kantipur Hospital, Kathmandu were collected between August, 2018 and March, 2019. Rectal swabs and urine specimens were cultured. E. coli isolated from the specimens were screened for antimicrobial susceptibility testing (AST) using disk diffusion method’. Minimum inhibitory concentration (MIC) of colistin was determined by agar dilution method using 0.5 µg/ml to 32 µg/ml. The E. coli isolates were first screened for mcr-1 followed by screening for OXA-48 genes using conventional Polymerase chain reaction (PCR). Results Of the total samples analyzed, E. coli was isolated from 31.7% (76/240) of poultry and 7.9% (56/705) of clinical specimens. In AST, 80% (61/76) of E. coli from poultry and 79% (44/56) from clinical specimens were MDR. The phenotypic prevalence of colistin resistance in poultry specimens were 31.6% (24/76) and clinical specimens were 21.4% (12/56). In PCR assay, 27.6% (21/76) of poultry and 19.6% (11/56) of clinical isolates had colistin resistant mcr-1 gene. MICs value of E. coli isolates ranged from 4 to 32 (µg/ml) in both clinical and poultry isolates. Prevalence of co-existing carbapenem resistance gene, OXA-48, among colistin resistant mcr-1 positive isolates was 38% (8/21) in poultry specimens and 18.2% (2/11) in clinical specimens. Conclusions The high prevalence of colistin and carbapenem resistant genes, and their co-existence in plasmid DNA of E. coli isolates in this study suggests the possible spread to other animal, human and environmental pathogens. Molecular methods in addition to the conventional diagnostics in laboratories can help in early diagnosis, effective management and control of their potential transmission.

scholarly journals Inaccuracy of the Disk Diffusion Method Compared with the Agar Dilution Method for Susceptibility Testing of Campylobacter spp.

2011 ◽  
Vol 50 (1) ◽  
pp. 52-56 ◽  
Author(s):  
Mirva Lehtopolku ◽  
Pirkko Kotilainen ◽  
Pauli Puukka ◽  
Ulla-Maija Nakari ◽  
Anja Siitonen ◽  
...  
Keyword(s):  
Susceptibility Testing ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Disk Diffusion Method ◽  
Agar Dilution ◽  
Campylobacter Spp
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