Detection of Macrolide and/or Fluoroquinolone Resistance Genes in Mycoplasma genitalium Strains Isolated from Men in the Northwest Region of Croatia in 2018-2023.

Mycoplasma genitalium (M. genitalium) poses a significant public health challenge due to its association with non-gonococcal urethritis (particularly in men) and antimicrobial resistance. However, despite the prevalence of M. genitalium infections and the rise in resistance rates, routine testing and surveillance remain limited. This is the first study from Croatia that aimed to assess the prevalence and trends of resistance in M. genitalium strains isolated from male individuals by detecting macrolide and fluoroquinolone resistance genes. The study also aimed to explore the factors associated with resistance and changes in resistance patterns over time. Urine samples collected from male individuals in the Zagreb County and northwest region of Croatia between 2018 and 2023 were tested for M. genitalium with the use of molecular methods. Positive samples were subjected to DNA extraction and multiplex tandem polymerase chain reaction (MT-PCR) targeting genetic mutations associated with macrolide (23S rRNA gene) and fluoroquinolone (parC gene) resistance. Of the 8073 urine samples tested from 6480 male individuals (and following the exclusion of repeated specimens), we found that the prevalence of M. genitalium infection was 2.2%. Macrolide resistance was observed in 60.4% of strains, while fluoroquinolone resistance was found in 19.2%. Co-resistance to both antibiotics was present in 18.2% of cases. A statistically significant increase in fluoroquinolone resistance was noted over the study period (p = 0.010), but this was not evident for azithromycin resistance (p = 0.165). There were no statistically significant differences in resistance patterns between age groups, whereas re-testing of patients revealed dynamic changes in resistance profiles over time. The high burden of macrolide resistance and increasing fluoroquinolone resistance underscore the urgent need for comprehensive resistance testing and surveillance programs. The implementation of resistance-guided treatment strategies, along with enhanced access to molecular diagnostics, is pivotal for effectively managing M. genitalium infections.

Diffusion of OXA-48 carbapenemase among urinary isolates of Klebsiella pneumoniae in non-hospitalized elderly patients.

BACKGROUND: Recently, a dramatic increase of Klebsiella pneumoniae positive for OXA-48 ß-lactamases was observed first in the hospital setting and later in the long-term care facilities (LTCFs) and community in the Zagreb County, particularly, in urinary isolates. The aim of the study was to analyse the epidemiology and the mechanisms of antibiotic resistance of OXA-48 carbapenemase producing K. pneumoniae strains isolated from urine of non-hospitalized elderly patients. RESULTS: The isolates were classified into two groups: one originated from the LTCFs and the other from the community. Extended-spectrum ß-lactamases (ESBLs) were detected by double disk-synergy (DDST) and combined disk tests in 55% of the isolates (51/92). The ESBL-positive isolates exhibited resistance to expanded-spectrum cephalosporins (ESC) and in majority of cases to gentamicin. LTCFs isolates showed a significantly lower rate of additional ESBLs and consequential resistance to ESC and a lower gentamicin resistance rate compared to the community isolates, similarly to hospital isolates in Zagreb, pointing out to the possible transmission from hospitals.ESBL production was associated with group 1 of CTX-M or SHV-12 ß-lactamases. Ertapenem resistance was transferable from only 12 isolates. blaOXA-48 genes were carried by IncL plasmid in 42 isolates. In addition IncFII and IncFIB were identified in 18 and 2 isolates, respectively. Two new sequence types were reported: ST4870 and ST4781. CONCLUSIONS: This study showed eruptive and extensive diffusion of OXA-48 carbapenemase to LTCFs and community population in Zagreb County, particularly affecting patients with UTIs and urinary catheters. On the basis of susceptibility testing, ß-lactamase production, conjugation experiments, MLST and plasmid characterization it can be concluded that there was horizontal gene transfer between unrelated isolates, responsible for epidemic spread of OXA-48 carbapenemase in the LTCFs and the community The rapid spread of OXA-48 producing K. pneumoniae points out to the shortcomings in the infection control measures.

Emergence of CTX-M group 1 extended-spectrum beta-lactamase-producing Klebsiella pneumoniae strains in the community.

AIM: Molecular characterization of ESBL-producing K. pneumoniae strains isolated from urine of outpatients in Zagreb region during the last five years. METHODS: During the five-year study period a total of 2, 651 K. pneumoniae strains were isolated from urine of nonhospitalized patients with significant bacteriuria. ESBL production was detected by double-disk diffusion technique and by > or = 3-dilution reduction in the minimal inhibitory concentration of ceftazidime in the presence of clavulanate. A total of 441 ESBL-producing K. pneumoniae strains (15.5%) were collected and 17 strains were further characterised. Double-disk synergy test was used to detect ESBLs. Minimum inhibitory concentrations (MICs) were determined by broth microdilution method according to CLSI. The transferability of cefotaxime resistance was tested by conjugation (broth mating method). PCR was used to detect alleles encoding ESBL enzymes. The genotypes of the strains were compared by pulsed-field gel electrophoresis (PFGE) of Xba I-digested genomic DNA. RESULTS: A significant difference in frequencies of ESBL isolates was observed. In the first year of study only 4.9% of isolated strains were ESBL producers, while in the second year 17.% ESBL-positive strains were detected (p < 0.01), and the frequency remained stabile within following years. All strains yielded an amplicon with primers specific for SHV beta-lactamases and CTX-M beta-lactamases. Based on sequencing of bla(CTX-M) genes enzymes of nine strains were identified as CTX-M 15 beta -lactamase and three as CTX-M-14. Isolates were not clonally related. CONCLUSION: The study demonstrated community-associated emergence of CTX-M 1 beta-lactamase-producing K. pneumoniae strains.

[Characteristics of uropathogens in outpatient catheter-associated urinary tract infections]. / Karakteristike uzrocnika urinarnih infekcija povezanih s kateterima u izvanbolnickoj populaciji.

During the two years period the prevalence of uropathogens responsible for catheter-associated urinary tract infection (CAUTI) in outpatients was investigated including their differences in antimicrobial susceptibility according to the age and gender. Indwelling urinary catheter (IUC) constitutes 0.3% of all processed urine samples. Significant bacteriuria was found in 92.5% of IUC, and polimicrobial ethiology in 63.2%. The most CAUTI (79.3%) was found in elderly male patients (> 65 years). The most frequently isolated uropathogens were Esherichia coli and other Enterobacteriaceae, Pseudomonas aeruginosa, and enterococci. The very high resistance of all Enterobacteriaceae to beta-lactams, fluoroquinolones, and co-trimoxazole was observed with significantly much higher fluoroquinolone (p < 0.01) and co-trimoxazole (p < 0.05) resistance in elderly male patients as compared with younger ones.