Incidence and Clinical Characteristics of Anaerobic Bacteremia at a University Hospital in Hungary: A 5-Year Retrospective Observational Study.

Strict anaerobes have been reported to account for 0.5-13% of episodes of bacteremia in the adult population, with a growing awareness among clinicians regarding anaerobic bacteremia, especially in patients with specific predisposing factors. The aim of our present study was to assess the incidence and clinical characteristics of anaerobic bacteremia during a 5-year period (2016-2020) at a tertiary care teaching hospital, and to compare our findings with other studies in Hungary. Overall, n = 160 strict anaerobes were detected, out of which, 44.4% (n = 71; 0.1% of positive blood cultures, 0.1/1000 hospitalizations, 3.3/100,000 patient days) were clinically significant, while Cutibacterium spp. accounted for 55.6% (n = 89) of isolates. Among relevant pathogens, the Bacteroides/Parabacteroides spp. group (32.4%; n = 23), Clostridium spp. (22.5%; n = 16) and Gram-positive anaerobic cocci (15.5%; n = 11) were the most common. The mean age of patients was 67.1 ± 14.1 years, with a male majority (59.2%; n = 42). A total of 38.0% of patients were affected by a malignancy or immunosuppression, while an abscess was identified in 15.5% of cases. A total of 74.7% (n = 53) of patients received antibiotics prior to blood culture sampling; in instances where antimicrobials were reported, anaerobic coverage of the drugs was appropriate in 52.1% (n = 37) of cases. The 30-day crude mortality rate was 39.4% (n = 28); age ≥ 75 years was a significant predictor of 30-day mortality (OR: 5.0; CI: 1.8-14.4; p = 0.003), while malignancy and immunosuppression, lack of anti-anaerobic coverage or female sex did not show a significant relationship with the mortality of these patients. Early recognition of the role played by anaerobes in sepsis and timely initiation of adequate, effective antimicrobial treatment have proven efficient in reducing the mortality of patients affected by anaerobic bacteremia.

Streptococcus suis: An Underestimated Emerging Pathogen in Hungary?

Streptococcus suis (S. suis) is an emerging zoonotic pathogen, demonstrated as an etiological agent in human infections in increasing frequency, including diseases like purulent meningitis, sepsis, uveitis-endophtalmitis and arthritis. Due to the increased availability and utility of novel diagnostic technologies in clinical microbiology, more studies have been published on the epidemiology of S. suis, both in veterinary and human medicine; however, there are no comprehensive data available regarding human S. suis infections from East-Central European countries. As a part of our study, data were collected from the National Bacteriological Surveillance (NBS) system on patients who had at least one positive microbiological result for S. suis, corresponding to an 18-year study period (2002-2019). n = 74 S. suis strains were isolated from invasive human infections, corresponding to 34 patients. The number of affected patients was 1.89 ± 1.53/year (range: 0-5). Most isolates originated from blood culture (63.5%) and cerebrospinal fluid (18.9%) samples. Additionally, we present detailed documentation of three instructive cases from three regions of the country and with three distinctly different outcomes. Hungary has traditional agriculture, the significant portion of which includes the production and consumption of pork meat, with characteristic preparation and consumption customs and unfavorable epidemiological characteristics (alcohol consumption, prevalence of malignant diseases or diabetes), which have all been described as important predisposing factors for the development of serious infections. Clinicians and microbiologist need to be vigilant even in nonendemic areas, especially if the patients have a history of occupational hazards or having close contact with infected pigs.

Dissemination of VanA-Type Enterococcus faecium Isolates in Hungary.

Although vanA carrying Enterococcus faecium human clinical isolates have been rarely found in Hungary before 2012, they have been detected in continuously increasing numbers since then. To identify factors associated with their dissemination, we investigated the clonal relatedness and plasmids of 30 vanA carrying E. faecium isolates originating from different Hungarian healthcare institutions from 2012 to 2014. Molecular typing of the isolates (n = 30) was performed with pulsed-field gel electrophoresis (PFGE), multilocus sequence typing, Tn1546 polymerase chain reaction mapping, plasmid restriction fragment length polymorphism analysis, and sequencing. A single Tn1546 variant was detected in all of the isolates. It harbored IS1251 in the vanS-vanH intergenic region, had an entire deletion of the transposase gene and a partial deletion of the resolvase gene, and was located on a pRUM-like plasmid. Based on PFGE, the isolates could be grouped into 13 pulsotypes. Representative strains of these pulsotypes belonged to ST17, ST18, ST80, ST117, and ST203, which are known to be part of the hospital-adapted clades. The increase in the number of vanA carrying E. faecium clinical isolates in Hungary could be explained by the dissemination of pRUM-like vancomycin resistance plasmids in hospital-adapted clonal lineages.

Re-evaluation of in vitro activity of primycin against prevalent multiresistant bacteria.

With the increasing emergence of antibiotic resistances old antibiotics became a valuable source to find agents suitable to address this problem. More than 20 years after the last report, our purpose was to re-evaluate the in vitro antibacterial activity of the topical agent primycin against current important bacterial pathogens. Minimal inhibitory concentrations (MIC) and minimal bactericidal concentrations (MBC) of primycin were tested in comparison with agents widely applied topically, and with those of mupirocin and vancomycin, the topical and the non-topical gold-standard anti-MRSA agents. Primycin was ineffective (MIC>64 µg/ml) against all the Gram-negative isolates tested. On the other hand, all the tested Gram-positive isolates were susceptible with MIC90 values of 0.06 µg/ml for staphylococci and 0.5-1 µg/ml for enterococci, streptococci, and P. acnes isolates, including all the multiresistant strains. Against MRSA isolates primycin showed slightly higher activity than mupirocin, and inhibited the mupirocin-resistant strains also. MBC90 values ranged from 0.25 to 2 µg/ml for the investigated Gram-positive species. The bactericidal effect proved to be concentration-dependent in time-kill experiments. Spontaneous resistant mutants did not emerge in single-step mutation experiments and the resistance development was very slow by serial passaging. Passaged S. aureus strains showing increased primycin MIC values exhibited elevated vancomycin and daptomycin MIC values also. Though elucidation of the mechanisms behind warrants further investigations, these correlations can be related to development of vancomycin-intermediate phenotype. From the point of view of medical practice it is noteworthy that the increased primycin MIC values remained far below the concentration accessible by local application of the agent. These data make primycin a remarkable object of further investigations as well as a promising candidate for topical application against multiresistant Gram-positive pathogens.