Current Fluoroquinolone Susceptibility Criteria for Salmonella Needs Re-evaluation

2012 ◽  
Vol 10 (1) ◽  
pp. 66-71 ◽  
Author(s):  
D Acharya ◽  
S Malla ◽  
DR Bhatta ◽  
N Adhikari ◽  
SP Dumre
Keyword(s):  
Nalidixic Acid ◽  
Enteric Fever ◽  
Susceptibility Testing ◽  
Break Point ◽  
Resistance Rate ◽  
Diffusion Method ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Disc Diffusion ◽  
Zone Diameter

Background Disc diffusion technique is the routine susceptibility testing procedure for isolates of enteric fever, the most common clinical diagnosis among febrile patients in Nepal. Objective To evaluated the current fluoroquinolones (FQs) susceptibility criteria and nalidixic acid screening test in Salmonella enterica serovar Typhi and Paratyphi A. Methods S. Typhi and Paratyphi A strains isolated from 443 suspected enteric fever patients visiting National Public Health Laboratory (NPHL) during April through October 2008 were analyzed. All isolates were confirmed by standard microbiological procedures including serotyping. Antibiotic susceptibility testing was performed by using Kirby Bauer disc diffusion method and Clinical and Laboratory Standards Institute (CLSI) approved interpretive criteria. Agar dilution method was used to determine Minimum Inhibitory Concentration (MIC) of ciprofloxacin, ofloxacin and nalidixic acid. Result Out of 41 Salmonella isolates, 80.49% were nalidixic acid resistant, with S. Paratyphi A showing higher resistance rate (88.23%) compared to S. Typhi (75%). The difference in both MIC and zone diameter in nalidixic acid susceptible and nalidixic acid resistant isolates was found to be significant (P < 0.001) and decreased susceptibility to FQs was strongly correlated (sensitivity and specificity of 100%) with resistance to nalidixic acid. Regression analysis of MIC against zone diameter based on the current CLSI recommended guidelines suggests that accommodation of current susceptible and resistant MIC requires increase in the zone diameter of ciprofloxacin and ofloxacin. Conclusion Before using these drugs for management of enteric fever, appropriate identification of Salmonella isolates with reduced susceptibility to FQs is essential to limit the possible treatment failure and development of highly resistant strains. The current FQs susceptibility break point criteria for Salmonella need re-evaluation. KATHMANDU UNIVERSITY MEDICAL JOURNAL  VOL.10 | NO. 1 | ISSUE 37 | JAN - MAR 2012 | 24-29DOI: http://dx.doi.org/10.3126/kumj.v10i1.6909

scholarly journals Nalidixic Acid Susceptibility Test for Screening Salmonella Isolates of Reduced Susceptibility/Higher Minimum Inhibitory Concentration to Ciprofloxacin

2015 ◽  
Vol 15 (2) ◽  
pp. 97-104 ◽  
Author(s):  
P. Agrawal ◽  
R. Tuladhar ◽  
N. Dahal
Keyword(s):  
Nalidixic Acid ◽  
Enteric Fever ◽  
Acid Resistance ◽  
Susceptibility Test ◽  
Diffusion Method ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Disc Diffusion ◽  
Antibiotic Susceptibility Test ◽  
Nalidixic Acid Resistance

Enteric fever is the major diagnosis among febrile patients in Nepal with yearly increase in nalidixic acid resistance and reduced ciprofloxacin susceptibility among Salmonella isolates. This study was carried out to evaluate the validity of nalidixic acid resistance as an indicator of reduced susceptibility of Salmonella isolates to ciprofloxacin. In this study, 999 blood specimens collected from suspected enteric fever patients visiting B&B Hospital were processed by standard microbiological techniques. Isolates were identified by biochemical tests and serotyping. Antibiotic susceptibility test was performed by Kirby Bauer disc diffusion method and CLSI recommended interpretive criteria. MIC of ciprofloxacin was determined by agar dilution method. Isolation rate of Salmonella species was 6.21%. Among 62 Salmonella isolates, 51 were S. typhi, 10 were S. paratyphi A and one isolate was S. paratyphi B. Only one isolate of S. typhi was multi-drug resistant. Resistance to ceftriaxone, cefixime and azithromycin was nil. On disc diffusion test, 55 isolates were resistant to nalidixic acid. Fifty-seven isolates were found to have increased (>0.125mg/ml) MIC of ciprofloxacin with the clinical and laboratory standards institute breakpoints. Nalidixic acid resistance showed a predictive value of 100% for ciprofloxacin resistance. Screening with nalidixic acid disc had a sensitivity of 100% and a specificity of 71.43% for the determination of decreased ciprofloxacin susceptibility. Before using ciprofloxacin for the treatment of enteric fever, appropriate identification of Salmonella isolates with reduced ciprofloxacin susceptibility is essential to limit the possible treatment failure and further development of highly resistant strains.DOI: http://dx.doi.org/njst.v15i2.12122Nepal Journal of Science and Technology Vol. 15, No.2 (2014) 97-104

scholarly journals Ciprofloxacin susceptibility of Salmonella enteric serovar Typhi and Paratyphi A from blood samples of suspected enteric fever patients

2012 ◽  
Vol 1 (1) ◽  
pp. 9-13 ◽  
Author(s):  
D Adhikari ◽  
D Acharya ◽  
P Shrestha ◽  
R Amatya
Keyword(s):  
Salmonella Enterica ◽  
Enteric Fever ◽  
Diffusion Method ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Disc Diffusion ◽  
Salmonella Spp ◽  
Blood Samples ◽  
Antibiotic Susceptibility Test

INTRODUCTION: Enteric fever caused by Salmonella enterica serovars Typhi and Paratyphi A is the common clinical diagnosis among febrile patients presenting to hospital in Nepal. The aim of this study was to evaluate the ciprofloxacin (CIP) and other antibiotics susceptibility patterns of Salmonella enterica serovars Typhi and Paratyphi A from blood samples of suspected enteric fever patients visiting KIST Medical College, Kathmandu. MATERIALS AND METHODS: Antibiotic susceptibility test was performed by Kirby Bauer disc diffusion method as per CLSI guidelines whereas MIC determination of ciprofloxacin was performed by agar dilution method. RESULTS: Altogether 64 presumptive Salmonella spp. were isolated from 840 blood samples of suspected enteric fever patients, of which 41 were S. Typhi and 23 were S. Paratyphi A. All Salmonella spp. isolates were sensitive to ceftriaxone and ofloxacin whereas 4 isolates were resistant to ciprofloxacin. One isolates each of S. Typhi and S. Paratyphi A were multidrug resistant. Fifty five isolates of Salmonella spp. were resistant to nalidixic acid (NA) with higher rate in S. Paratyphi A (91.3%) compared to S. Typhi (82.9%). MIC determination of ciprofloxacin revealed that majority of the isolates were resistant to ciprofloxacin and 2 isolates were resistant with MIC value of 4 µg/ml and 8 µg/ml. Importantly, we found simultaneous presence of NA resistance and decreased susceptibility to CIP suggesting that resistance to NA is a reliable indicator of decreased CIP susceptibility. CONCLUSIONS: Disc diffusion test failed to detect the reduced susceptibility of ciprofloxacin. Hence the MIC determination of ciprofloxacin against Salmonella spp. isolates would be important.  DOI: http://dx.doi.org/10.3126/ijim.v1i1.6938Int J Infect Microbiol 2012;1(1):9-13

scholarly journals Susceptibility to patterns of ciprofloxacin among nalidixic acid-resistant Salmonella isolates collected in Banepa, Nepal from enteric fever patients

2016 ◽  
Vol 89 (2) ◽  
Author(s):  
Girija Roka ◽  
Subash Pandaya ◽  
Md. Reyad-ul Ferdous ◽  
Manson Pandey ◽  
Naba Raj Pokhrel ◽  
...  
Keyword(s):  
Nalidixic Acid ◽  
Salmonella Enterica ◽  
Enteric Fever ◽  
Inhibitory Concentration ◽  
Acid Resistance ◽  
Dilution Method ◽  
Disc Diffusion ◽  
Antimicrobial Sensitivity ◽  
Broth Dilution ◽  
Nalidixic Acid Resistance

The present study determined the susceptibility to ciprofloxacin of nalidixic acid resistant <em>Salmonella</em> (NARS) isolated from enteric fever patients at Scheer Memorial Hospital, Banepa, Nepal, from June 2012 to December 2012. The antimicrobial sensitivity to nalidixic acid and ciprofloxacin was determined using modified Kirby-Bauer disc diffusion and broth dilution method according to the guidelines of the Clinical and Laboratory Standard Institute. <em>Salmonella</em> was isolated from 34 out of 992 (3.43%) blood cultures collected during the study period, and 10 (29.4%) isolates were identified as <em>Salmonella enterica</em> serotype Typhi, while 24 (70.6%) were identified as <em>Salmonella enterica</em> serotype Paratyphi. Out of the total isolates, 31 (91.2%) were nalidixic acid-resistant <em>Salmonella</em> (NARS). Among NARS, the minimum inhibitory concentration values for ciprofloxacin ranged from 0.25 to 2 mg/L and were constantly higher than those shown by the nalidixic acid-susceptible <em>Salmonella</em>. Therefore, in typhoid <em>Salmonella</em> nalidixic acid resistance may be the indicator of decreased susceptibility to ciprofloxacin.

scholarly journals A study on Nalidixic Acid Resistant Salmonella among the patients attending Shree Birendra Hospital

2012 ◽  
Vol 10 (2) ◽  
pp. 1-3 ◽  
Author(s):  
Raina Chaudhary ◽  
Khagendra Sijapati ◽  
Sunil Kumar Singh
Keyword(s):  
Nalidixic Acid ◽  
Salmonella Enterica ◽  
Enteric Fever ◽  
Brain Heart Infusion ◽  
Public Health Problem ◽  
Diffusion Method ◽  
Disc Diffusion ◽  
Diffusion Test ◽  
Sensitivity Pattern

Introduction: Enteric fever is the commonest public health problem in developing countries like Nepal. Multi Drug Resistant Salmonella isolates are in vitro susceptible to Quinolone but exhibited a higher Minimum Inhibitory Concentration in vivo. Such phenomenon can be demonstrated by simple disc diffusion test of Nalidixic Acid which shows resistance. This study is conducted to determine prevalence of Nalidixic Acid Resistant Salmonella with their anti biotic sensitivity pattern at Shree Birendra Hospital, Chauni, kathmandu. Method: Of total 3945 blood samples from the patients suspected to have enteric fever were collected during the period of January 2011 to August 2011. Then it was mixed with Brain Heart Infusion , further processed according to standard methodology and their anti microbial susceptibility was performed by Kirby-Bauer disc diffusion method. Results: From 3945 samples, 280 (7.09%) showed positi ve growth, 114 (40.7%) Salmonella enterica serotype Typhi and 166 (59.2%) Salmonella enterica serotype Paratyphi A. a total of 221 (78.92%) were Nalidixic Acid Resistant Salmonella, all these strains were sensitive to Ciprofloxcin and Ofloxacin in disc diffusion test. Conclusion: Study showed a higher frequency of Nalidixic Acid Resistant Salmonella among the patients. screening of Nalidixic Acid disc diffusion test must be done as routine work for determination of low level resistance of Quinolone so as to decide the drug for the treatment of enteric fever. DOI: http://dx.doi.org/10.3126/mjsbh.v10i2.6453 Medical Journal of Shree Birendra Hospital July-Dec 2011 10(2) 1-3

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 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

scholarly journals COLISTIN RESISTANCE IN CARBAPENEM-RESISTANT KLEBSIELLA PNEUMONIAE STRAINS

2017 ◽  
Vol 10 (9) ◽  
pp. 70
Author(s):  
Beena Hosdurg Bhaskar ◽  
Shalini Shenoy Mulki ◽  
Sangeeta Joshi ◽  
Ranjeeta Adhikari ◽  
Bhavana Malavalli Venkatesh
Keyword(s):  
Antibiotic Susceptibility ◽  
Antimicrobial Agents ◽  
Susceptibility Testing ◽  
Ethylenediaminetetraacetic Acid ◽  
Diffusion Method ◽  
Resistance Pattern ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Antibiotic Susceptibility Testing ◽  
Carbapenem Resistant

Objective: There is an increasing use of colistin consequent to increase in the infections caused by carbapenem-resistant Klebsiella pneumoniae.The present study was conducted to determine the minimum inhibitory concentration (MIC) of colistin and the resistance pattern of colistin in carbapenem-resistant K. pneumoniae (CRKP) strains in our intensive care unit (ICU).Methods: Antibiotic susceptibility testing for other antimicrobial agents was done by Kirby-Bauer disk diffusion method. MIC of colistin was determined by agar dilution method. The results of antibiotic susceptibility testing were interpreted as per Clinical Laboratory Standard Institute guidelines 2016 and MIC of colistin were interpreted as per European Committee on Antimicrobial susceptibility testing. The carbapenem resistance was phenotypically detected by modified hodge test and imipenem/imipenem ethylenediaminetetraacetic acid disk method.Results: Out of 518 K. pneumoniae, 329 were resistant to carbapenems, and 91 isolates showed resistance to colistin. The MIC of colistin ranged between 4 and >512 ug/ml and MIC90 was 16 ug/L and MIC50 was 4 ug/ml. A majority of the colistin-resistant isolates were found in multidisciplinary ICU (85/91).Conclusion: The emergence of colistin-resistant strains is a major problem due to limited treatment options for infections caused by CRKP carbapenemase producing K. pneumoniae. Colistin should not be used alone, combination therapy should be preferred.

scholarly journals Phenotypic and Molecular Detection of Extended-spectrum beta-lactamase among Ceftazidime Resistant Pseudomonas aeruginosa Isolated from Wound Swab.

2018 ◽  
Vol 12 (1) ◽  
pp. 15-19
Author(s):  
Sharmin Sultana ◽  
Shikha Paul ◽  
Akhtarun Naher ◽  
Rahima Akter ◽  
Tarina Khan
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Standard Procedure ◽  
Diffusion Method ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Disc Diffusion ◽  
College Hospital ◽  
Esbl Gene ◽  
Resistant Strains ◽  
Esbl Producers

ESBL producing Pseudomonas aeruginosa has been reported to be an important cause of nosocomial infection. The study was undertaken to determine ESBL producing Pseudomonas aeruginosa by phenotypic method and to detect bla OXA-10 ESBL gene by molecular method. A total of 288 wound infection cases attending the in-patient department of Mitford Hospital and Dhaka Medical College Hospital were enrolled for this study. Pseudomonas aeruginosa was isolated following standard procedure and subjected to antimicrobial susceptibility test by disc-diffusion method. Ceftazidime resistant strains were confirmed by MIC by agar dilution method. Confirmed ceftazidime resistant strains were tested for ESBL production by CLSI phenotypic confirmatory disc diffusion test (PCDDT) and bla OXA-10 ESBL gene was identified by employing conventional PCR. Out of 92 Pseudomonas aeruginosa, confirmed ceftazidime resistant strains were 60. PCDDT detected 49 (81.67%) ESBL producers and PCR detected 44 (73.33%) positive strains for bla OXA-10 ESBL gene among 60 ceftazidime resistant strains of Pseudomonas aeruginosa. The study showed high proportion of ESBL producers among ceftazidime resistant Pseudomonas aeruginosa. Bangladesh J Med Microbiol 2018; 12 (1): 15-19

scholarly journals Comparative Analysis of Gradient Diffusion and Disk Diffusion with Agar Dilution for Susceptibility Testing of Elizabethkingia anophelis

Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 450
Author(s):  
Chien-Tung Chiu ◽  
Chung-Hsu Lai ◽  
Yi-Han Huang ◽  
Chih-Hui Yang ◽  
Jiun-Nong Lin
Keyword(s):  
Antimicrobial Agents ◽  
Susceptibility Testing ◽  
Disk Diffusion ◽  
Diffusion Method ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Disk Diffusion Method ◽  
Gradient Diffusion ◽  
Minimum Requirements ◽  
Agar Dilution

Elizabethkingia anophelis has recently emerged as a cause of life-threatening infections. This study compared the results of antimicrobial susceptibility testing (AST) conducted for E. anophelis through different methods. E. anophelis isolates collected between January 2005 and June 2019 were examined for their susceptibility to 14 antimicrobial agents by using disk diffusion, gradient diffusion (Etest; (bioMérieux S.A., Marcy l’Etoile, France), and agar dilution methods. The agar dilution method was the reference assay. According to the agar dilution method, the isolates exhibited the highest susceptibility to minocycline (100%), doxycycline (97.6%), rifampin (95.2%), and levofloxacin (78.6%). A very major error rate of >1.5% was observed for nine antibiotics tested using the disk diffusion method. The overall categorical agreement rate between the disk diffusion and agar dilution methods was 74.8%, and ceftazidime, minocycline, levofloxacin, and rifampin met the minimum requirements for discrepancy and agreement rates. The Etest method tended to produce lower log2 minimum inhibitory concentrations for the antibiotics, except for trimethoprim–sulfamethoxazole and rifampin; the method resulted in very major errors for nine antibiotics. The overall essential and categorical agreement rates between the Etest and agar dilution methods were 67.3% and 76.1%, respectively. The Etest method demonstrated acceptable discrepancy and agreement rates for ceftazidime, minocycline, doxycycline, levofloxacin, and rifampin. AST results obtained through the disk diffusion and Etest methods for multiple antibiotics differed significantly from those obtained using the agar dilution method. These two assays should not be a routine alternative for AST for E. anophelis.

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.

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