scholarly journals Vancomycin heteroresistance in Staphylococcus haemolyticus: elusive phenotype

2021 ◽  
pp. FSO710
Author(s):  
Yamuna Devi Bathavatchalam ◽  
Dhanalakshmi Solaimalai ◽  
Anushree Amladi ◽  
Hariharan Triplicane Dwarakanathan ◽  
Shalini Anandan ◽  
...  
Keyword(s):  
Population Analysis ◽  
Meca Gene ◽  
Gene Mutations ◽  
Bloodstream Infections ◽  
Rpob Gene ◽  
Staphylococcus Haemolyticus ◽  
Routine Surveillance ◽  
Sequence Types ◽  
Profile Area ◽  
Staphylococcal Cassette Chromosome

Aim: To determine the presence of vancomycin heteroresistance in Staphylococcus haemolyticus. Materials & methods: A total of 48 rifampicin-resistant S. haemolyticus isolates from bloodstream infections were included. Vancomycin heteroresistance was determined using the population analysis profile-area under curve (PAP-AUC) method. All the isolates were screened for the presence of mecA gene, mutations in the rpoB gene, staphylococcal cassette chromosome  mec and multilocus sequence types. Results: Fifteen isolates were identified as heteroresistant vancomycin-intermediate S. haemolyticus using PAP-AUC method. Dual rpoB mutations (D471E and I527M) contributed for the rifampicin resistance. The sequence types of heteroresistant vancomycin-intermediate S. haemolyticus were highly diverse. Conclusion: These findings illustrate the potential of  S. haemolyticus to develop heteroresistance, which emphasizes the need for routine surveillance of S. haemolyticus isolated from intensive care units for infection control practices.

scholarly journals Screening for Intermediately Vancomycin-Susceptible and Vancomycin-Heteroresistant Staphylococcus aureus by Use of Vancomycin-Supplemented Brain Heart Infusion Agar Biplates: Defining Growth Interpretation Criteria Based on Gold Standard Confirmation

2015 ◽  
Vol 53 (11) ◽  
pp. 3543-3546 ◽  
Author(s):  
Riad Khatib ◽  
Kathleen Riederer ◽  
Mamta Sharma ◽  
Stephen Shemes ◽  
Sugantha P. Iyer ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Gold Standard ◽  
Population Analysis ◽  
Area Under The Curve ◽  
Brain Heart Infusion ◽  
Roc Curves ◽  
Clinical Samples ◽  
Content Type ◽  
Interpretation Criteria ◽  
Profile Area

BHI agars supplemented with vancomycin 4 (BHI-V4) and 3 (BHI-V3) mg/liter have been proposed for screening vancomycin intermediately susceptibleStaphylococcus aureus(VISA) and heteroresistant (hVISA) phenotypes, respectively, but growth interpretation criteria have not been established. We reviewed the growth results (CFU) during population analysis profile-area under the curve (PAP-AUC) of consecutive methicillin-resistantStaphylococcus aureus(MRSA) blood isolates, which were saved intermittently between 1996 and 2012. CFU counts on BHI-V4 and BHI-V3 plates were stratified according to PAP-AUC interpretive criteria: <0.90 (susceptible [S-MRSA]), 0.90 to 1.3 (hVISA), and >1.3 (VISA). CFU cutoffs that best predict VISA and hVISA were determined with the use of receiver operating characteristic (ROC) curves. Mu3, Mu50, and methicillin-susceptibleS. aureus(MSSA) controls were included. We also prospectively evaluated manufacturer-made BHI-V3/BHI-V4 biplates for screening of 2010-2012 isolates. The PAP-AUC of 616 clinical samples was consistent with S-MRSA, hVISA, and VISA in 550 (89.3%), 48 (7.8%), and 18 (2.9%) instances, respectively. For VISA screening on BHI-V4, a cutoff of 2 CFU/droplet provided 100% sensitivity and 97.7% specificity. To distinguish VISA from hVISA, a cutoff of 16 CFU provided 83.3% sensitivity and 94.7% specificity; the specificity was lowered to 89.5% with a 12-CFU cutoff. For detecting hVISA/VISA on BHI-V3, a 2-CFU/droplet cutoff provided 98.5% sensitivity and 93.8% specificity. These results suggest that 2-CFU/droplet cutoffs on BHI-V4 and BHI-V3 best approximate VISA and hVISA gold standard confirmation, respectively, with minimal overlap in samples with borderline PAP-AUC. Simultaneous screening for VISA/hVISA on manufacturer-made BHI-V4/BHI-V3 biplates is easy to standardize and may reduce the requirement for PAP-AUC confirmation.

scholarly journals Bacterial genotypic and patient risk factors for adverse outcomes in Escherichia coli bloodstream infections: a prospective molecular-epidemiological study

2021 ◽  
Author(s):  
Elita Jauneikaite ◽  
Kate Honeyford ◽  
Oliver Blandy ◽  
Mia Mosavie ◽  
Max Pearson ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Length Of Stay ◽  
Single Agent ◽  
Bloodstream Infections ◽  
Outcome Data ◽  
Sequence Type ◽  
Adverse Outcomes ◽  
Beta Lactam ◽  
E Coli ◽  
Sequence Types

Background Escherichia coli bloodstream infections have increased rapidly in the UK, for reasons that are unclear. The relevance of highly fit, or multi-drug resistant lineages such as ST131 to overall E. coli disease burden remains to be fully determined. We set out to characterise the prevalence of E. coli multi-locus sequence types (MLST) and determine if these were associated with adverse outcomes in an urban population of E. coli bacteraemia patients. Methods We undertook whole genome sequencing of E. coli blood isolates from all patients with diagnosed E. coli bacteraemia in north-west London from July 2015 to August 2016 and assigned multi-locus sequence types to all isolates. Isolate sequence types were linked to routinely collected antimicrobial susceptibility, patient demographic, and clinical outcome data to explore relationships between the E. coli sequence types, patient factors, and outcomes. Findings A total of 551 E. coli genomes were available for analysis. More than half of these cases were caused by four E. coli sequence types: ST131 (21%), ST73 (15%), ST69 (9%) and ST95 (8%). E. coli genotype ST131-C2 was associated with non-susceptibility to quinolones and third-generation cephalosporins, and also to amoxicillin, augmentin, gentamicin and trimethoprim. An association between the ST131-C2 lineage and longer length-of-stay was detected, although multivariable regression modelling did not demonstrate an association between E. coli sequence type and mortality. However, a number of unexpected associations were identified, including gentamicin non-susceptibility, ethnicity, and sex that might influence mortality and length-of-stay, requiring further research. Interpretation Although E. coli sequence type was associated with antimicrobial non-susceptibility patterns and length-of-stay, we did not find that E. coli sequence type was associated with increased mortality. Where ST131 is prevalent, caution is required when pairing beta-lactam agents with gentamicin or using single agent aminoglycosides.

scholarly journals Biological microchips for detection of multiple drug resistant M. tuberculosis strains isolated in Kyrgyz Republic

2008 ◽  
pp. 64-66
Author(s):  
J. T. Isakova ◽  
Z. K. Goncharova ◽  
A. A. Aldashev
Keyword(s):  
Drug Resistance ◽  
Pulmonary Tuberculosis ◽  
Gene Mutations ◽  
Rpob Gene ◽  
Multiple Drug ◽  
Drug Resistant ◽  
Kyrgyz Republic ◽  
Newly Diagnosed ◽  
Single Drug ◽  
Multiple Drug Resistant

The aim of the study was to estimate spread of primary and secondary multiple drug resistant Mycobacterium tuberculosis (MBT) and to characterize rpoB, katG, inhA, and ahpC gene mutations of rifampicin (RIF) and isoniazid (INH) resistant MBT strains isolated from tuberculosis patients in Kyrgyz. We obtained 493 specimens from patients with pulmonary tuberculosis which were diagnosed based on clinical, X-ray, and bacteriological examination. Among them, newly diagnosed pulmonary tuberculosis was in 445 patients (90.2 %), and 48 of the patients (9.8 %) have already been treated for tuberculosis. Mutations of rpoB, KatG, inhA, and ahpC genes associated with RIF and INH resistance were detected by biological chip test. Sensitive MBT strains were detected in 47 % and resistant strains were in 53 % of the newly diagnosed patients. Single-drug resistance to RIF only was detected in 3 % of cases; resistance to INH was found in 20 %, resistance to both the drugs was detected in 30 % of the patients. In pre-treated patients single-drug resistance to RIF was defined in 4 % of cases, resistance to INH was in 8 %, resistance to both the drugs was estimated in 75 % of the patients. Therefore, we suppose that there is a high prevalence of multi-drug resistant MBT in Kyrgyz Republic: 30 % among newly diagnosed patients and 75 % among pre-treated patients. The main cause of RIF-resistance of MBT is Ser531→Leu mutation of rpoB gene, and the main cause of INHresistance is Ser315→Thr mutation of katG gene.

scholarly journals Risk factors for E. coli Susceptibility in Bloods Stream Infections in England Between 2013-2017

2019 ◽  
Vol 29 (Supplement_4) ◽  
Author(s):  
S Aliabadi ◽  
K Honeyford ◽  
E Jauneikaite ◽  
B Muller-Pebody ◽  
C Costelloe
Keyword(s):  
Risk Factors ◽  
Logistic Regression ◽  
Bloodstream Infections ◽  
Visual Assessment ◽  
Outcome Variable ◽  
Antibiotic Prescribing ◽  
Cross Sectional ◽  
E Coli ◽  
Routine Surveillance ◽  
Potential Risk Factors

Abstract Antimicrobial resistance (AMR) is a significant threat to global health. Escherichia coli is a frequent cause of Gram-Negative Bloodstream Infections (GNBSIs) and a key organism that contributes to the burden of AMR. This was a cross-sectional surveillance study that looked at 154,791 isolates between 1st January 2013 and 31st December 2017. Analysis was performed using routine surveillance data from Public Health England (PHE) containing data on the incidence and susceptibility results of E. coli bacteraemia. Exposure variables extracted were potential risk factors for AMR. The outcome variable was resistance to at least one antibiotic. Descriptive statistics and graphs were used to summarise the data. Associations between variables and the resistance to at least one antibiotic were assessed using univariate logistic regression. A multivariable logistic regression examined adjusted associations between the variables and resistance to at least one antibiotic. The final model included variables that showed strong evidence of association with resistance to at least one antibiotic. 43.2% of isolates were resistant to at least one antibiotic. Logistic regression showed an association between resistance of E. coli isolates to at least one antibiotic and children of school age (1.39 OR, 95% CI: 1.18-1.64; p ≤ 0.001), isolates taken from patients in Greater Manchester (1.50 OR, 95% CI: 1.41-1.60; p ≤ 0.001) and isolates taken from male patients (1.14 OR, 95% CI: 1.11-1.17; p ≤ 0.001), on adjustment. Visual assessment of trend graphs showed a decrease in resistance for common carbapenems and piperacillin/tazobactam. Prevalence of resistance has increased for common cephalosporins, gentamicin, and co-amoxiclav. Initial analyses suggest an increase in rates of E. coli resistance to at least one antibiotic in GNBSIs between 2013 and 2017 in England. Findings of this study have implications for appropriate antibiotic prescribing guidelines and for directing future AMR policies. Key messages Initial analysis of the dataset suggests that rates of AMR of E. coli in BSIs have increased between 2013 and 2017. There is evidence of an increase in E.coli infections that are resistant to cephalosporins over time and a decrease in E.coli infections that are resistant to carbapenems.

scholarly journals Resistance profiles and rpoB gene mutations of Mycobacterium tuberculosis isolates in Taiwan

2013 ◽  
Vol 46 (4) ◽  
pp. 266-270 ◽  
Author(s):  
Yun-Ho Lin ◽  
Chun-Hsi Tai ◽  
Chia-Ru Li ◽  
Chin-Fu Lin ◽  
Zhi-Yuan Shi
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Gene Mutations ◽  
Rpob Gene

scholarly journals Type V Staphylococcal Cassette Chromosome mec in Community Staphylococci from Australia

2005 ◽  
Vol 49 (12) ◽  
pp. 5129-5132 ◽  
Author(s):  
F. G. O'Brien ◽  
G. W. Coombs ◽  
J. C. Pearson ◽  
K. J. Christiansen ◽  
W. B. Grubb
Keyword(s):  
Australian Community ◽  
Type V ◽  
Sequence Types ◽  
Staphylococcal Cassette Chromosome

ABSTRACT Twenty Australian community staphylococci harboring the type V staphylococcal cassette chromosome mec (SCCmec) were found to belong to eight multilocus sequence types. Five were previously unreported novel type V SCCmec elements. The mec complexes were of two types, based on the polymorphisms in the IS431 transposase genes. Five isolates were multiresistant.

Sign in / Sign up

Export Citation Format

Share Document