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.

Isolation and Characterization of a Novel Lytic Bacteriophage against the K2 Capsule-Expressing Hypervirulent Klebsiella pneumoniae Strain 52145, and Identification of Its Functional Depolymerase.

Klebsiella pneumoniae is among the leading bacteria that cause nosocomial infections. The capsule of this Gram-negative bacterium is a dominant virulence factor, with a prominent role in defense and biofilm formation. Bacteriophages, which are specific for one bacterial strain and its capsule type, can evoke the lysis of bacterial cells, aided by polysaccharide depolymerase enzymes. In this study, we isolated and characterized a bacteriophage against the nosocomial K. pneumoniae 52145 strain with K2 capsular serotype. The phage showed a narrow host range and stable lytic activity, even when exposed to different temperatures or detergents. Preventive effect of the phage in a nasal colonization model was investigated in vivo. Phlyogenetic analysis showed that the newly isolated Klebsiella phage B1 belongs to the Webervirus genus in Drexlerviridae family. We identified the location of the capsule depolymerase gene of the new phage, which was amplified, cloned, expressed, and purified. The efficacy of the recombinant B1dep depolymerase was tested by spotting on K. pneumoniae strains and it was confirmed that the extract lowers the thickness of the bacterium lawn as it degrades the protective capsule on bacterial cells. As K. pneumoniae strains possessing the K2 serotype have epidemiological importance, the B1 phage and its depolymerase are promising candidates for use as possible antimicrobial agents.

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.

Effect of antifungal agents on protein composition of Candida albicans studied by capillary electrophoresis and chip technology.

In the present study protein profile of a Candida albicans strain had been examined by chip technology and conventional capillary electrophoresis (CE). Profiles could be characterised by the presence of ten dominating protein peaks. These proteins could be distinguished by both techniques, but their quantity showed significant differences in the electropherograms obtained by CE and chip method. Changes in the protein profile were induced by administration of different antifungal agents. Fluconazole and amphotericin B treatment was able to induce similar changes in the pattern, appearance of a 40-kDa protein and up-regulation of a 60-kDa protein was observed by chip technology. Increase in the quantity of these proteins under stress effect (antifungal treatment) might refer to their stress function in the fungal cell. Treatment of C. albicans cells with MK 94 (fused cyclic Mannich ketone) antifungal compound induced not only the previously mentioned changes, but further specific alterations, appearance of a 19-kDa protein and up-regulation of the low molecular weight proteins. This might refer to the different mode of action of this agent on the fungal cells. Conventional capillary electrophoresis was suitable to detect the appearance of the 19-kDa peak, and up-regulation of the 60 kDa protein, but the other changes could not be detected by this technique. Shorter running time, more effective and baseline separation of proteins refer to the advantages of microchip-based method in the analysis of complex biological samples.