Species diversity and antimicrobial resistance of Staphylococcus spp. isolates associated with catheter-related bloodstream infections in patients after hematopoietic stem cell transplantation

Abstract

INTRODUCTION: The human body is colonized by a large number of different bacterial and fungal species, with most microorganisms inhabiting the skin, oral cavity, and the lower parts of the gastrointestinal tract. AIM: The aim of this study was to investigate the species diversity of clinically significant Staphylococcus spp. isolates, obtained from blood cultures of patients with central venous catheter (CVC) following hematopoietic stem cell transplantation (HSCT) during the period January 2019-December 2020, as well as to test their susceptibility to a set of antimicrobials. MATERIALS AND METHODS: A total of 21 non-duplicate clinically significant staphylococcal isolates from blood cultures of 17 patients with implemented CVCs following HSCT were obtained. The Bactec and Phoenix automated systems (BD, USA) were used for identification and antimicrobial susceptibility testing. RESULTS: In the collected group of 21 isolates, 85.7% were coagulase-negative staphylococci (CoNS): S. epidermidis, n=12; S. haemolyticus, n=4; S. hominis, n=2, and 3 isolates were identified as S. aureus. Methicillin resistance was 85.7% and was detected only in the CoNS group. In decreasing order, the resistance rates in CoNS group were as follows: 100% for penicillin and cefoxitin >83.3% erythromycin >72.2% ciprofloxacin >61.1% gentamicin >44.4% for clindamycin and trimethoprim/sulfamenthoxazole. No resistance to vancomycin, teicoplanin, and linezolid was found. S. aureus isolates demonstrated preserved susceptibility to all antimicrobials with exception to penicillin. CONCLUSION: In the present study, CoNS were identified as the most common cause of catheter-related bloodstream infections (BSIs) in patients following HSCT, with S. epidermidis being the predominant spe-

Clinical characteristics and mortality risk factors of mixed bacterial infections in hematopoietic stem cell transplantation recipients

“…Our antibiotic susceptibility tests showed that CoNS was completely sensitive to vancomycin and linezolid, and slightly resistant to penicillin and aminoglycosides. This was somewhat different from what Niyazi D previously reported ( Niyazi et al., 2022 ): They found CoNS resistance rates to penicillin, erythromycin, gentamicin, and ciprofloxacin all exceeding 60%, significantly higher than our statistical results. We speculate that this may be caused by the high proportion of methicillin-resistant CoNS in their study cohort.…”

Microbiological Monitoring: Sisyphean Labor?

“…In this issue of Scripta Scientifica Medica, Niyazi et al (1) analyzed a spectrum of clinically significant Staphylococcus spp. colonized central venous catheter (CVC) in the most immunosuppressed category of patients, those who have undergone hematopoietic cell transplantation (HCT) in myeloablative chemotherapyinduced aplasia, a reversible life threatened condition.…”