Epidemic Klebsiella pneumoniae ST258 incidence in ICU patients admitted to a university hospital in Istanbul

INTRODUCTION

Klebsiella pneumoniae sequence type 258 (ST258) strains are globally distributed multi-drug resistant pathogens and can spread rapidly throughout the world, causing severe healthcare-associated invasive infections with limited antimicrobial treatment options. The aim of this study was to reveal the incidence of Klebsiella pneumoniae ST258 strains among the intensive care unit patients in a university hospital in Istanbul.

METHODOLOGY

Consecutive nonreplicated 83 K. pneumoniae strains were isolated from various clinical samples of intensive care unit patients admitted to a university hospital in Istanbul, between November 2016 to December 2018. Bacterial identifications were performed via VITEK2. Antimicrobial susceptibility tests were conducted with Kirby Bauer's disc diffusion test except for colistin which was performed with broth microdilution. Real-time PCR method was utilized in order to reveal ST258 positivity among the strains.

RESULTS

Antimicrobial susceptibility results revealed that 56 (67%) K. pneumoniae strains were carbapenem-resistant. Real-time PCR results demonstrated that 15 out of 83 (18%) K.pneumoniae strain were ST258. According to antimicrobial susceptibility test results of ST258 strains, 8 were found as carbapenem-resistant whereas 7 were found as carbapenem susceptible. 3 out of 8 (37.5%) carbapenem-resistant ST258 strains were found as resistant against all antibiotics tested.

CONCLUSIONS

Our study revealed that K. pneumoniae ST258 which caused severe infections worldwide so far has also spread to Istanbul. We believe that rapid molecular methods for monitorization of these clones are useful. our results showed that ST258 is not linked to a multi-resistant strain and suggested that it does not contribute to multi-resistance formation alone.

Should we leave the paper currency? A microbiological examination

Objetives

Pathogens can be transmitted to banknotes due to the personal unhygienic habits. The aim of study was to find the possible pathogens on the banknotes circulating in the market and also to present their antibacterial resistance and their various virulence factors using genotypic and phenotypic methods.

Material and methods

A total of 150 samples of banknotes were randomly collected between August 2017 and March 2018. VITEK systems were used for identification and antimicrobial susceptibility testing respectively. Antimicrobial resistance genes (mecA, van, extended-spectrum β-lactamase [ESBL] and carbapenemases) and staphyloccoccal virulence genes (staphyloccoccal enterotoxins [SEs], pvl, and tsst-1) were determined using with real-time PCR.

Results

Staphylococcus aureus, coagulase-negative staphylococci (CoNS), Enterococcus spp., Gram-negative enteric bacteria, non-fermentative Gram-negative bacteria and Candida spp. were detected 48%, 54.7%, 56%, 21.3%, 18.7%, and 4%, respectively. Methicillin-resistant S. aureus, vancomycin-resistant enterococci and ESBL producing Gram-negative were found 46.8%, 1.3%, and 28.7%, respectively. Pvl, tsst-1, and SEs genes were found in a 2.8/4.9%, 1.4/1.2%, and 100/ 87.8% of the S. aureus/CoNS strains, respectively. The sea gene was found the most common enterotoxigenic gene. bla_TEM, bla_SHV, blaCTX-M-2, blaCTX-M-1, bla_KPC, and blaOXA-48 were found 55.8%, 46.5%, 41.2%, 18.6%, 18.6%, and 18.6%, respectively in Gram-negative strains.

Conclusion

These results is very important to highlight hygienic status of paper currencies. This can be considered as an indication that banknotes may contribute to the spread of pathogens and antimicrobial resistance. Therefore, we may need to start using alternative products instead of banknotes.

Detection of O25b-ST131 clone, CTX-M-1 and CTX-M-15 genes via real-time PCR in Escherichia coli strains in patients with UTIs obtained from a university hospital in Istanbul

BACKGROUND

Escherichia coli sequence type 131 is an important multidrug resistant clone responsible from more than half of ESBL-producing E.coli isolates. Aim of this study was to investigate the presence of O25b-ST131 clone, CTX-M-15 and CTX-M-1 genes in the E. coli strains isolated from both hospital and community acquired UTIs by real-time PCR and to reveal molecular epidemiological data.

METHODS

Non-duplicate E. coli (n = 101) strains isolated from UTI patients were included. Bacterial identifications were performed with VITEK Compact. Antimicrobial susceptibility tests, phenotypic ESBL and E-tests were performed conventionally. Real-time PCR was utilized to detect presence of O25b-ST131 clone, blaCTX-M-15 and blaCTX-M-1.

RESULTS

O25b-ST131 clone, CTX-M-1 and CTX-M-15 were detected in 22%, 73%, 37% in UTIs, respectively. Presence of O25b-ST131 clones and CTX-M-1 genes among E. coli strains isolated from inpatients were found statistically higher than outpatients. The most effective choice was found to be fosfomycin and nitrofurantoin in outpatients and inpatients, respectively. The MIC₉₀ values of Amikacin, Cefotaxime, Cefepime and Ciprofloxacin were higher in inpatients than in oupatients, whereas Cefotaxime and Ciprofloxacin MIC₅₀ values were found to be higher in inpatients than in outpatients. The highest increase of MIC₉₀ values was observed in O25b-ST131, CTX-M-1 and CTX-M-15 coexistence.

CONCLUSION

The presence of O25b-ST131 clone, CTX-M-1 and CTX-M-15 genes in E. coli strains in patients with UTI has been revealed. In the presence of the O25b-ST131 clone, a significant increase was observed in the ciprofloxacin MIC values indicating the importance of monitorization of the clone using molecular epidemiology.