Corynebacterium glucuronolyticum in men with and without urethritis syndrome: An underrecognized pathogen or a bona fide commensal?

BACKGROUND

By analysing the largest collection of Corynebacterium glucuronolyticum (C. glucuronolyticum) isolates from a single centre thus far, we aimed to appraise a potential causal link between an infrequently isolated species and the urethritis syndrome in men.

METHODS

A total of 1055 Caucasian male individuals with or without urethritis syndrome were included in this single-centre case-control study. Group-wise comparisons were pursued by analysing sociodemographic, behavioural and microbiological specificities between the two groups. C. glucuronolyticum isolates from urethral specimens were identified using the analytical profile index biotyping system (API Coryne) and additionally confirmed by MALDI-TOF mass-spectrometry, with subsequent determination of their antimicrobial sensitivity profiles. Statistical significance was set at p < 0.05 (two-tailed).

RESULTS

C. glucuronolyticum was isolated in 5.08% of study participants with urethritis syndrome and 3.60% of those without it (p = 0.303). In the urethritis group, the species was more frequently found as a sole isolate (p = 0.041) and after prior infection with Chlamydia trachomatis (p = 0.025). The most frequent presentation of urethritis included a clear discharge in small or moderate amounts, without any pathognomonic findings. The resistance rates were 62.22% for clindamycin, 42.22% for tetracycline and 26.67% for ciprofloxacin.

CONCLUSIONS

Our study provides major insights on the relevance of urethral C. glucuronolyticum in non-gonococcal urethritis, with significant implications for further aetiological research and management approaches.

The impact of Corynebacterium glucuronolyticum on semen parameters: a prospective pre-post-treatment study

Corynebacterium glucuronolyticum (C. glucuronolyticum) is a rare isolate that is only recently being acknowledged as a potential urogenital pathogen. The bibliographical references on this bacterial species are scarce, and its influence on all semen parameters was hitherto unknown - therefore, the aim of this study was to evaluate its effects on a range of sperm quality parameters. A prospective approach to compare semen parameters before and after treatment was used in this study. C. glucuronolyticum in semen specimens was identified using analytical profile index biotyping system (API Coryne) and additionally confirmed by matrix-assisted laser desorption/ionization time-of-flight mass-spectrometry (MALDI-TOF MS), with the determination of antimicrobial susceptibility by Kirby-Bauer method. Semen analysis was performed according to the criteria from the World Health Organization (with the use of Tygerberg method of sperm morphology categorization). Very strict inclusion criteria for participants also included detailed medical history and urological evaluation. From a total of 2169 screened semen specimens, the inclusion rate for participants with C. glucuronolyticum that satisfied all the criteria was 1.01%. Antibiogram-guided treatment of the infection with ensuing microbiological clearance has shown that the resolution of the infection correlates with statistically significant improvement in the vitality of spermatozoa, but also with a lower number of neck and mid-piece defects. Parameters such as sperm count, motility and normal morphology were not affected. In addition, susceptibility testing revealed a trend towards ciprofloxacin resistance, which is something that should be considered when selecting an optimal treatment approach. Albeit it is rarely encountered as a monoisolate in significant quantities, C. glucuronolyticum may negatively influence certain sperm parameters; therefore, it has to be taken into account in the microbiological analysis of urogenital samples.

Increased prevalence of toxoplasma gondii seropositivity in patients with treatment-resistant schizophrenia

Introduction

Previous studies suggested that patients with schizophrenia had an increased prevalence of antibodies against toxoplasma gondii (TG) and that those seropositive patients had higher symptom severity. However, there is no data on the relationship between treatment-resistant schizophrenia (TRS) and TG seroprevalence.

Objectives

To determine the association between TRS and TG seropositivity, and to further investigate the relationship between TG seropositivity and different clinical features of schizophrenia.

Methods

In this cross-sectional study, we included 210 male inpatients with schizophrenia. TG seropositivity was determined by ELFA assay. Treatment-resistance was defined as a failure of at least 2 adequate anti-psychotic trials. Data were analyzed using χ2 test or Mann–Whitney test.

Results

The rate of TG seropositivity in the entire sample was 52.3%, whereas 47.6% of patients met the definition for treatment-resistance. Seropositive patients had twice the rate of treatment–resistance compared to seronegative patients (63.6% vs. 30.0%, P < 0.0001). Moreover, in the seropositive group, the patients were older (47.6 ± 12.2 vs. 39.81 ± 12.01 years, P < 0.0001), had higher number of previous hospitalizations (13.9 ± 11.7 vs. 9.6 ± 8.5, P = 0.0073), and increased Calgary depression scale for schizophrenia (CDSS) total score (7.8 ± 4.5 vs. 6.3 ± 3.8, P = 0.012). There were no differences between the groups in the age of disease onset, smoking, positive and negative syndrome scale (PANSS) total, positive and negative scores, and the life-time history of suicide attempts.

Conclusions

Our results support the hypothesis that TG seropositivity might contribute to treatment-resistance in schizophrenia, at least in male patients.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Seroepidemiology of Hepatitis E in Selected Population Groups in Croatia: A Prospective Pilot Study

Hepatitis E has become an emerging infection in many European countries. We analysed the prevalence of hepatitis E virus (HEV) infection in selected population groups in Croatia. Overall HEV IgG seropositivity was 5.6%, while 1.9% participants showed IgM antibodies suggestive of recent infection. No IgM-positive sample was positive for HEV RNA. HEV IgG antibodies were most prevalent in alcohol abusers (8.9%) and war veterans (8.6%), compared with 6.1% among injecting drug users and 2.7% in healthcare professionals. No individual with high-risk sexual behaviour tested HEV seropositive. HEV IgG positivity increased significantly with age from 1.8% to 2.3% in individuals younger than 40 years to 11.3% in individuals older than 50 years (P = 0.023). The mean age of HEV-positive participants was significantly higher than that of HEV-negative participants (50.9 ± 11.8 years versus 41.2 ± 11.8 years, P = 0.008). Seroprevalence rates were significantly higher in residents of suburban and rural areas compared with residents of urban areas (14.5% versus 2.5%, P = 0.003). Additionally, an increasing prevalence of HEV IgG antibodies was observed from 1.8% in participants living in families with two household members to 12.1% in those living with more than four members (P = 0.046). Gender, marital status, educational level, sexual orientation, source of drinking water, history of blood transfusions, surgical procedures, tattooing and travelling were not associated with HEV seroprevalence. Logistic regression showed that living in suburban/rural areas was the main risk factor for HEV seropositivity (OR = 6.67; 95%CI = 1.89-25.0; AOR = 7.14, 95%CI = 1.89-25.0).

Antimicrobial susceptibility and beta-lactamase production of selected gram-negative bacilli from two Croatian hospitals: MYSTIC study results

The meropenem yearly Susceptibility Test Information Collection (MYSTIC) programme is a global, longitudinal resistance surveillance network that monitors the activity of meropenem and compares its activity with other broadspectrum antimicrobial agents. We now report the antimicrobial efficacy of meropenem compared to other broad-spectrum agents within the selective Gram-negative pathogen groups from two Croatian Hospitals investigated between 2002-2007. A total of 1510 Gram-negative pathogens were tested and the minimum-inhibitory concentrations (MICs) were determined by broth microdilution method according to CLSI.There was no resistance to either imipenem or meropenem observed for Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis in both medical centers. High resistance rates of K. pneumoniae to ceftazidime (18%), cefepime (17%) and gentamicin (39%) are raising concern. Acinetobacter baumannii turned out to be the most resistant Gram-negative bacteria with 81% resistant to ceftazidime, 73% to cefepime, 69% to gentamicin and 71% to ciprofloxacin. Almost 20% of Pseudomonas aeruginosa strains were resistant to imipenem, 13% to meropenem, 69% to gentamicin and 38% to ciprofloxacin.The prevalence of extended-spectrum beta-lactamases (ESBLs) in E. coli was 10% and in K. pneumoniae 49%. PCR and sequencing of the amplicons revealed the presence of SHV-5 in nine E. coli strains and additional tem-1 beta-lactamase five strains. Five K. pneumoniae strains were positive for bla(SHV-5 )gene. Eight ESBL positive Enterobacter spp. strains were found to produce tem and CtX-m beta-lactamases. Plasmid-mediated AmpC beta-lactamases were not found among K. pneumoniae, E. coli and Enterobacter spp. Three A. baumannii strains from Zagreb University Center were identified by multiplex PCR as OXA-58 like producers. Six A. baumannii strains from Split University Center were found to possess an ISAba1 insertion sequence upstream of bla(OXA-51 )gene. According to our results meropenem remains an appropriate antibiotic for the treatment of severe infections caused by Gram-negative bacteria. These data indicate that despite continued use of meropenem, carbapenem resistance is not increasing among species tested, except for A. Baumannii, in the two study hospitals and suggest that clinicians can still administer carbapenems as a reliable and effective choice in managing serious nosocomial infections.

Sensitivity and specificity of various beta-lactam antibiotics and phenotypical methods for detection of TEM, SHV and CTX-M extended-spectrum beta-lactamases

The aim of this study was to compare the sensitivity and specificity of six different beta-lactam antibiotics using five phenotypical tests for detection of extended spectrum beta-lactamases (ESBLs) based on synergism of beta-lactam antibiotics and clavulanate. Experiments were performed on a set of 80 Klebsiella pneumoniae strains and 105 Escherichia coli strains with previously characterized ESBLs (SHV, TEM and CTX-M). ESBLs were detected by five different phenotypical methods: MIC (minimum inhibitory concentration) determination of beta-lactam antibiotics with and without clavulanate, double-disk synergy test (DDST), inhibitor-potentiated disk-diffusion test (IPDDT), CLSI-Clinical and Laboratory Standard Institution (former NCCLS) combined-disk-test, and modified MAST-disk-diffusion test (MAST-DD-test). Seven antibiotics were tested as indicators of ESBL production: ceftazidime, cefotaxime, ceftriaxone, aztreonam, ceftibuten, cefpodoxime and cefepime. Ceftazidime and aztreonam were the best indicators for SHV-5, SHV-12 and TEM beta-lactamases whereas cefotaxime and ceftriaxone were the most sensitive in detection of SHV-2 and CTX-M beta-lactamases in DDST, IPDDT and CLSI test. MIC determination of beta-lactam antibiotics with and without clavulanate was the most sensitive method. DDST was the least sensitive test. Double-disk synergy test, which is the most frequently used test for detection of ESBLs in routine laboratories, was the least sensitive independently of the indicator antibiotic. Since MIC determination is a very laborious and time consuming method, we would recommend the NCCLS combined disk test or IPDD test for detection of ESBLs in routine laboratories with 5 mm zone augmentation breakpoint.