Antimicrobial susceptibility tests for anaerobic bacteria. Comparison of Wilkins-Chalgren agar reference method and a microdilution method, and determination of stability of antimicrobics frozen in broth

1978 ◽  
Vol 1 (2) ◽  
pp. 81-83 ◽  
Author(s):  
R. N. Jones ◽  
P. C. Fuchs ◽  
C. Thornsberry ◽  
N. Rhodes
Keyword(s):  
Antimicrobial Susceptibility ◽  
Anaerobic Bacteria ◽  
Reference Method ◽  
Microdilution Method ◽  
Antimicrobial Susceptibility Tests ◽  
Susceptibility Tests

Serotype Occurrence and Antimicrobial Susceptibility of Salmonella Isolates Recovered from Pork Carcasses in Taiwan (2000 through 2003)

2006 ◽  
Vol 69 (3) ◽  
pp. 674-678 ◽  
Author(s):  
TER-HSIN CHEN ◽  
YU-CHIH WANG ◽  
YI-TSENG CHEN ◽  
CHIA-HUEI YANG ◽  
KUANG-SHENG YEH
Keyword(s):  
Salmonella Typhimurium ◽  
Antimicrobial Susceptibility ◽  
Antimicrobial Agents ◽  
Screening Program ◽  
Serotype Distribution ◽  
Minimum Concentration ◽  
Microdilution Method ◽  
Antimicrobial Susceptibility Tests ◽  
Salmonella Serotypes ◽  
Susceptibility Tests

One hundred fifty-eight Salmonella strains isolated from pork carcasses in a nationwide screening program in Taiwan from 2000 through 2003 were analyzed for serotype distribution and antimicrobial susceptibility. Twenty Salmonella serotypes were obtained, among which Derby, Anatum, Typhimurium, and Schwarzengrund were the most frequently isolated, accounting for 76% of the strains. Antimicrobial susceptibility tests with the microdilution method were performed on these serotypes to determine the MIC. All strains tested were sensitive to ceftriaxone, with an MIC90 (minimum concentration inhibiting 90% of isolates tested) of 0.25 to 8 μg/ml. More than 60% of the strains were resistant to ampicillin, chloramphenicol, tetracycline, nalidixic acid, and sulfamethoxazole, with MIC90 values of 128 to >512 μg/ml. More than 80% of the Salmonella Schwarzengrund strains were resistant to ciprofloxacin (MIC90 = 8 μg/ml) and enrofloxacin (MIC90 = 16 μg/ml). The Salmonella Typhimurium strains exhibited 17 and 23% resistance to ciprofloxacin and enrofloxacin, respectively, with an MIC90 of 8 μg/ml, and these two antibiotics also were active against Salmonella Derby and Salmonella Anatum. Cephalothin, gentamicin, and trimethoprim had limited activity against Salmonella Anatum and Salmonella Schwarzengrund, with MIC90 values of 256 to >512 μg/ml. Cephalothin and gentamicin were moderately active against Salmonella Derby and Salmonella Typhimurium, but 30 to 40% of these strains were resistant to trimethoprim. The Salmonella strains isolated from pork carcasses in Taiwan were relatively resistant to the antimicrobial agents tested, with the exception of ceftriaxone. Although a variety of MIC values were obtained, generally these values were high.

scholarly journals Five years prospective survey of antibiotic resistance in Bacteroides and Parabacteroides isolated from inpatients of clinical hospital in Warsaw, Poland

2020 ◽  
pp. 13-19
Keyword(s):  
Clavulanic Acid ◽  
Antimicrobial Susceptibility ◽  
Bacterial Infections ◽  
Anaerobic Bacteria ◽  
Empirical Therapy ◽  
Drug Susceptibility ◽  
Clinical Isolates ◽  
Patient Treatment ◽  
Antimicrobial Susceptibility Tests ◽  
Susceptibility Tests

Objectives: Diagnostics of anaerobic bacterial infections and determination of drug susceptibility are technically difficult and time-consuming; therefore, the number of studies on Anaerobic Gram-negative bacilli is significantly limited, especially in Europe. The aim of the study was to analyze the antibiotic susceptibility of clinically important anaerobic bacteria Bacteroides spp. and Parabacteroides distasonis. Strains were isolated from infections of patients hospitalized at one Polish hospital as a result of routine microbiological diagnostics. Material and methods: Clinical isolates were identified with MALDI-TOF MS. Antimicrobial susceptibility of 276 strains was carried out by E-test gradient strip to commonly used antibiotics i.e. benzylpenicillin, amoxicillin with clavulanic acid, imipenem, clindamycin and metronidazole. MIC values were determined. The interpretation of antimicrobial susceptibility tests were conducted in accordance with The European Committee on Antimicrobial Susceptibility Testing (EUCAST) recommendations. Results: Susceptibility tests of all isolates yielded the following rates of resistance to the evaluated β-lactam antibiotics: benzylpenicillin (96%), amoxicillin/clavulanic acid (7.6%), imipenem (2.1%). In presented study 38.8% of clindamycin-resistant strains were isolated, among them 18.3% of B. fragilis and 53.85% P. distasonis. All strain were susceptible to metronidazole. Conclusions: Obtained results and analysis of the results of other researchers convinces us that it is necessary to routinely or at least periodically monitor drug susceptibility of clinical isolates of anaerobic bacteria and use targeted therapy based on the result of the antibiogram. Although high percentage of the tested Bacteroides and Parabacteroides strains remained susceptible to metronidazole and β-lactam antibiotics the use of clindamycin in empirical therapy may not be efficacious. Antibiogram results should be consult with the staff responsible for patient treatment and hospital antibiotic policies.

scholarly journals The accuracy of four commercial broth microdilution tests in the determination of the minimum inhibitory concentration of colistin

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Erlangga Yusuf ◽  
Mireille van Westreenen ◽  
Wil Goessens ◽  
Peter Croughs
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Antimicrobial Susceptibility ◽  
Inhibitory Concentration ◽  
Clinical Isolates ◽  
Reference Standard ◽  
Broth Microdilution ◽  
Antimicrobial Susceptibility Tests ◽  
Susceptibility Tests ◽  
Composite Reference Standard

Abstract Colistin is considered as one of the last-resort antibiotics and reliable antimicrobial susceptibility testing is therefore crucial. The reference standard for AST according to EUCAST and CLSI is broth microdilution (BMD). However, BMD is labor intensive to perform. Commercial antimicrobial susceptibility tests derived from BMD method are available. We investigated the performance of four different commercial tests: Sensititre™, SensiTest™ Colistin, Micronaut MIC Strip Colistin and UMIC Colistin using 70 clinical isolates (half of them was deemed by VITEK2 as resistant), including isolates from cystic fibrosis patients and mcr-1 bearing isolates. We used two reference standards: BMD and composite MIC as determined by all four tests. Sensititre™ had essential agreement (EA, defined as minimum inhibitory concentration within ± 1 dilution) of 87% and 89% compared to BMD and composite reference standard, respectively. For SensiTest™, the EA’s were 93% and 90%. For UMIC, 87% and 90%, and for Micronaut, 83% and 84%. All four tests demonstrated categorical agreement (CA) above 90%. CA for SensiTest™ and Micronaut was both 96%, UMIC 94%, and Sensititre™ 93%. All tests were reproducible as tested in two quality control isolates. In conclusion, in clinical isolates from a large referral center, the four commercial tests for determination of colistin minimum inhibitory concentrations showed acceptable performance.

scholarly journals Diagnosis and Treatment of Human Salmonellosis in Addis Ababa City, Ethiopia

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Legesse Garedew ◽  
Semaria Solomon ◽  
Yoseph Worku ◽  
Hilina Worku ◽  
Debela Gemeda ◽  
...  
Keyword(s):  
Antimicrobial Susceptibility ◽  
Addis Ababa ◽  
Clinical Signs ◽  
Diagnosis And Treatment ◽  
Widal Test ◽  
Predictive Values ◽  
Blood Samples ◽  
Antimicrobial Susceptibility Tests ◽  
Stool Samples ◽  
Susceptibility Tests

Background. Diagnosis using reliable tools and treatment followingin vitroantimicrobial susceptibility tests are critical to proper addressing of antibiotic-resistantSalmonellainfection.Methodology. A cross-sectional study was conducted to assess the practice of diagnosis and treatment of salmonellosis in Addis Ababa. Tube Widal test (for blood samples only), culture, biochemical and carbohydrate fermentation, serotyping, and antimicrobial susceptibility tests were employed for both blood and stool samples.Results. Of all the diseases listed in the diagnosis, nontyphoidal (n=72, 13.71%) and typhoidal (n=47, 8.95%) salmonellosis were the second and third common diseases. Among the 288 blood samples, almost half were positive for O, H, or both antigens. However, only 1 (0.68%) of the positive blood samples yieldedSalmonellaisolate during culture. The study demonstrated low specificity (0.68%) and positive predictive value (48.78%) of Widal test. Conversely, the test showed 100% sensitivity and negative predictive values.Salmonellaisolates were identified from 7 (7.07%) of 99 stool samples. Two-thirds of salmonellosis suspected patients received antibiotic treatment. However, only half of the confirmed salmonellosis patients were treated with appropriate antibiotics. All of the isolates were susceptible to ciprofloxacin and ceftriaxone but resistant to ampicillin.Conclusions. Majority of the patients who participated in this study were wrongly diagnosed using symptoms, clinical signs, and tube Widal test. Consequently, most of the patients received inappropriate treatment.

Yersinia enterocolitica isolates from humans in California, 1968-1975

1976 ◽  
Vol 4 (2) ◽  
pp. 137-144
Author(s):  
M L Bissett
Keyword(s):  
Yersinia Enterocolitica ◽  
Antimicrobial Susceptibility ◽  
Breast Abscess ◽  
Biochemical Tests ◽  
California Department ◽  
Biochemical Characteristics ◽  
Serotype O ◽  
Department Of Health ◽  
Antimicrobial Susceptibility Tests ◽  
Susceptibility Tests

This paper reports on the serological and biochemical characteristics of 24 human isolates of Yersinia enterocolitica submitted to the California Department of Health from 1968 through 1975. Nine different serotypes were represented. The majority of strains were serotype O:8 (six strains) and serotype O:5 (five strains). Sources of the isolates included feces (12 cases), blood (3), sputum or throat (3), bile or bowel drainage (2), wounds (2), breast abscess (1), and skin abscess (1). Clinical histories indicated a number of different syndromes. Underlying medical conditions existed in 13 cases. Results of selected biochemical tests and antimicrobial susceptibility tests on the strains indicated grouping compatible with the O serotypes of the organisms.

scholarly journals Trends in Antibiotic Resistance of Major Uropathogens

2020 ◽  
Author(s):  
Falah Hasan Obayes AL-Khikani
Keyword(s):  
Urinary Tract Infection ◽  
Urinary Tract ◽  
Tract Infection ◽  
Antimicrobial Susceptibility ◽  
Bacterial Species ◽  
High Rate ◽  
Control Group ◽  
Microbiological Methods ◽  
Antimicrobial Susceptibility Tests ◽  
Susceptibility Tests

Around the world, there is no population clear from urinary tract infection (UTI), particularly among women. UTI is considered the most predominant bacterial infection. This study aimed to detect the incidence of the most common major uropathogens in patients severe from urinary tract infection with antibiotic sensitivity tests that assist urologist doctors for appropriate antimicrobial empirical therapy.Methods: This study was carried in a private laboratory in Babil city, Iraq from May 2019 to May 2020. Totally 70 individuals suffering from clear symptoms of UTI, as well as, 20 healthy persons participated in this study as a control group. Then, the standard microbiological methods carried out to isolate and identify bacterial species. Antimicrobial susceptibility tests were performed using different antimicrobial discs by applying the Kirby–Bauer disc diffusion method.Results: Totally, 90 specimens were obtained from them 20 control group, 19 with no growth, and 51 patients with bacterial growth distributed as 43 (83%) females and 8 (17%) males. E. coli were the most common predominant organisms. All isolates were showed a high rate of resistance to evaluated cephalosporins 100% and 82% to cefotaxime and ceftriaxone respectively, while very low resistance recorded in Aminoglycosides 20% and 13% to Gentamicin and amikacin respectively. Most age group infected with UTI was 21-40 years old.Conclusion: The current study showed an increasing burden of urinary tract infection caused by various bacteria implicated in UTI that causes changeable sensitivity to various antimicrobial agents. Therefore, in clinical use appropriate medications should be selected based on the data obtained from antimicrobial susceptibility tests.

Sign in / Sign up

Export Citation Format

Share Document