Paucisymptomatic infectious prostatitis as a cause of fever without an apparent origin. A series of 19 patients

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.

Bacteriospermia - A formidable player in male subfertility

Bacterial colonization of male reproductive tissues, cells, and fluids, and the subsequent impact of bacteria on the sperm architecture, activity, and fertilizing potential, has recently gained increased attention from the medical and scientific community. Current evidence strongly emphasizes the fact that the presence of bacteria in semen may have dire consequences on the resulting male fertility. Nevertheless, the molecular basis underlying bacteriospermia-associated suboptimal semen quality is sophisticated, multifactorial, and still needs further understanding. Bacterial adhesion and subsequent sperm agglutination and immobilization represent the most direct pathway of sperm-bacterial interactions. Furthermore, the release of bacterial toxins and leukocytic infiltration, associated with a massive outburst of reactive oxygen species, have been repeatedly associated with sperm dysfunction in bacteria-infested semen. This review serves as a summary of the present knowledge on bacteriospermia-associated male subfertility. Furthermore, we strived to outline the currently available methods for assessing bacterial profiles in semen and to outline the most promising strategies for the prevention and/or management of bacteriospermia in practice.

One, No One and One Hundred Thousand: Patterns of chronic prostatic inflammation and infection

Chronic prostatic inflammation may be classified into three types that share similar symptoms and are distinguished on the basis of microbiological findings. In the present study, consecutive cases of chronic prostatic inflammation and infection were retrospectively reviewed in order to explore the clinical course and long-term outcomes. The cohort consisted of patients with symptoms of prostatitis who visited the Urology Clinic of the Tzaneion Hospital (Piraeus, Greece) between March 2009 and March 2019. The patients were subjected to the Meares and Stamey ‘4-glass’ test and patients with febrile prostatitis were evaluated with a single mid-stream ‘clean’ urine sample culture. Bacterial identification was performed using the Vitek 2 Compact system and the sensitivity test with the disc and the Vitek 2 system. A total of 656 patients with prostatitis-like symptoms with 1,783 visits for investigation and follow-up were reviewed and patients were divided into two major groups. Group 1 consisted of 549 cases with a single set of chronic prostatitis (CP)-like symptoms assessed in up to three visits. National Institutes of Health (NIH) category II CP (NIH-II) was most frequently diagnosed in those patients (37,6%). At the follow-up, 125 patients were identified as having a type of CP different from that determined initially. Group 2 (107 cases) had recurring episodes of prostatitis-like symptoms assessed or confirmed over the course of 4-18 visits. Most patients (54.2%) were initially diagnosed with NIH-II followed by disease-free periods and recurrence/reinfection or by shifts to NHI-IIIB. In conclusion, CP remains a poorly understood n medical condition characterized by a variety of clinical manifestations and by transitions between different CP classes during its course.

A 'pathogenic needle' in a 'commensal haystack': Genetic virulence signatures of Corynebacterium glucuronolyticum that may drive its infectious propensity for the male urogenital system

The predominance of the genus Corynebacterium in the healthy male urogenital system contributes to the resident microbiome of not only the distal urethra, but potentially the proximal urethra and urinary bladder as well. However, for certain species in this genus, pathogenic potential was described, and the salient representative is Corynebacterium glucuronolyticum (C. glucuronolyticum) implicated in cases of urethritis and prostatitis in men. Nonetheless, some still question whether C. glucuronolyticum can actually be considered pathogenic or rather just a commensal species fortuitously isolated in patients with urogenital symptoms and/or syndromes. Although pathogen/commensal dichotomy is not always clear-cut, we hypothesize that specific genetic markers may expose C. glucuronolyticum as a convincingly pathogenic Corynebacterium. More specifically, characteristic pathogenic gene constellation inherent to this species (most notably the presence of specific sortase/SpaA-type pili gene clusters, but also the augmentative role of type VII secretion system) may significantly facilitate host tissue adhesion, with subsequent suppression/evasion of the immune response and acquisition of vitally important nutrients. Consequently, these genetic markers differentiate C. glucuronolyticum from its commensal counterparts, and give this species a pathogenic facet, which can be even further influenced by the Allee effect. In this paper we also propose a specific methodological approach on how to analyze C. glucuronolyticum epithelial colonization capacity and explore inceptive host cell-pathogen interactions that manipulate host environment and immune responses. This entails moving from approaches based primarily on overall homology of primary sequences towards specific structure-function studies to precisely evaluate all stakeholders involved in pili assemblage, cell adhesion and the expression of other virulence traits. In the era of high precision medicine, the hypothesized roles of C. glucuronolyticum adhesion systems in both virulence and nutrient acquisition may also reveal promising targets for future drug developments.

A microbial game of whack-a-mole: clinical case series of the urethral uncloaking phenomenon caused by Corynebacterium glucuronolyticum in men treated for Chlamydia trachomatis urethritis

Corynebacterium glucuronolyticum is a rare and neglected, but increasingly recognized bacterial agent of infectious urethritis and other genitourinary syndromes in men. This is the first description of its proclivity to resurface as a cause of sustained urethritis in male patients previously treated for Chlamydia trachomatis, which represents a phenomenon that has to be differentiated from a simple post-treatment overgrowth of a colonizing agent.

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.

Toll-Like Receptor 2 and Mincle Cooperatively Sense Corynebacterial Cell Wall Glycolipids

Nontoxigenic Corynebacterium diphtheriae and Corynebacterium ulcerans cause invasive disease in humans and animals. Host sensing of corynebacteria is largely uncharacterized, albeit the recognition of lipoglycans by Toll-like receptor 2 (TLR2) appears to be important for macrophage activation by corynebacteria. The members of the order Corynebacterineae (e.g., mycobacteria, nocardia, and rhodococci) share a glycolipid-rich cell wall dominated by mycolic acids (termed corynomycolic acids in corynebacteria). The mycolic acid-containing cord factor of mycobacteria, trehalose dimycolate, activates the C-type lectin receptor (CLR) Mincle. Here, we show that glycolipid extracts from the cell walls of several pathogenic and nonpathogenic Corynebacterium strains directly bound to recombinant Mincle in vitro Macrophages deficient in Mincle or its adapter protein Fc receptor gamma chain (FcRγ) produced severely reduced amounts of granulocyte colony-stimulating factor (G-CSF) and of nitric oxide (NO) upon challenge with corynebacterial glycolipids. Consistently, cell wall extracts of a particular C. diphtheriae strain (DSM43989) lacking mycolic acid esters neither bound Mincle nor activated macrophages. Furthermore, TLR2 but not TLR4 was critical for sensing of cell wall extracts and whole corynebacteria. The upregulation of Mincle expression upon encountering corynebacteria required TLR2. Thus, macrophage activation by the corynebacterial cell wall relies on TLR2-driven robust Mincle expression and the cooperative action of both receptors.

Corynebacterium glucuronolyticum causing genitourinary tract infection: Case report and review of the literature

Corynebacterium species are increasingly recognized as opportunistic pathogens. A growing number of taxonomic studies has yielded a description of numerous new Corynebacterium species, such as those related to the urogenital tract, with Corynebacterium glucuronolyticum found to be rarely involved in genitourinary tract infections, particularly in male individuals. In this report, we describe a urethritis case caused by C. glucuronolyticum in a 37-year-old, apparently healthy male, who complained mild pain in the lower abdomen, with several urinary symptoms. While urethral and semen specimens did not yield positive results for microbiological evaluation, cultures of urine samples revealed the monomicrobial growth on blood-containing media of tiny colonies after 24 h of incubation, clearly evident only after 48 h of incubation under CO2-enriched atmosphere. Colonies were identified as C. glucuronolyticum both by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) and 16S rRNA gene sequencing. Oral ciprofloxacin gradually led to clinical improvement and, finally, to a complete recovery, in accordance with microbiological findings. In spite of its infrequent detection, C. glucuronolyticum might be a potential urogenital pathogen in males more commonly that what believed, perhaps due to slow growth leading to underrecognition; we suggest therefore to consider the organism in the differential diagnostics of bacterial diseases of the urinary tract.