Paweł Krzyściak

Case report: onychomycosis due to Trichophyton schoenleinii.

Trichophyton schoenleinii is an antropophilic dermatophyte transmitted by contact between humans. This genus is an aetiological agent of mycosis of the scalp – tinea favosa. Infections with T. schoenleinii were the most frequent dermatomycoses in Poland before the Second World War. Improvements in living conditions and hygiene after the Second World War have led to considerable decrease of infection with this fungus. We describe a patient who had a toenails involvement due to T. schoenleinii.

The usefulness of biotyping in the determination of selected pathogenicity determinants in Streptococcus mutans.

BackgroundStreptococcus mutans is known to be a primary etiological factor of dental caries, a widespread and growing disease in Polish children. Recognition of novel features determining the pathogenicity of this pathogen may contribute to understanding the mechanisms of bacterial infections.The goal of the study was to determine the activity of prephenate dehydrogenase (PHD) and to illuminate the role of the enzyme in S. mutans pathogenicity. The strains were biotyped based on STREPTOtest 24 biochemical identification tests and the usefulness of biotyping in the determination of S. mutans pathogenicity determinants was examined.ResultsOut of ninety strains isolated from children with deciduous teeth fifty three were classified as S. mutans species. PDH activity was higher (21.69 U/mg on average) in the experimental group compared to the control group (5.74 U/mg on average) (P <0.001). Moreover, it was demonstrated that biotype I, established basing on the biochemical characterization of the strain, was predominant (58.5%) in oral cavity streptococcosis. Its dominance was determined by higher PDH activity compared to biotypes II and III (P = 0.0019).ConclusionsThe usefulness of biotyping in the determination of Streptococcus mutans pathogenicity determinants was demonstrated. The obtained results allow for better differentiation of S. mutans species and thus may contribute to recognition of pathogenic bacteria transmission mechanisms and facilitate treatment.

Dermatophyte species in superficial mycoses in the Krakow district, Poland in the years 1972-2007

Considerable changes in the dermatophyte spectrum have been observed in the past century. Hence, many authors point out the necessity of performing periodical overviews of the mycological flora producing mycoses in humans in a given area. Analysis of dermatophyte species was performed, which were isolated from the lesions in patients suspected of superficial mycosis and referred to the Department of Mycology. The materials were isolated from patients suspected of superficial mycosis from Kraków region from January 1, 1972 through December 31, 2007. A total of 4983 dermatophyte strains were isolated from 23 124 specimens, which amounts to 21.5%. The percentage of dermatophytes isolated in the past decade decreased to 13.1% in the year 2007. Trichophyton rubrum outnumbered Trichophyton mentagrophytes during the entire survey period: 62.4 vs. 33.5%. The participation of Microsporum canis amounted to 1.71% and that of Epidermophyton floccosum to 1.32%. The species M. canis appeared by the end of the 1980s. The remaining dermatophyte species comprised 1% of the isolates. A considerable decrease in dermatophyte isolations has been observed since 2000. Trichophyton rubrum outnumbered T. mentagrophytes during the entire period of study. The percentages of T. rubrum and T. mentagrophytes are decreasing while the percentages of other dermatophytes are slowly increasing.

Occurrence of fungi and cytotoxicity of the species: Aspergillus ochraceus,Aspergillus niger and Aspergillus flavus isolated from the air of hospital wards

OBJECTIVES The basic care requirement for patients with weakened immune systems is to create the environment where the risk of mycosis is reduced to a minimum. MATERIAL AND METHODS Between 2007 and 2013 air samples were collected from various wards of a number of hospitals in Kraków, Poland, by means of the collision method using MAS-100 Iso MH Microbial Air Sampler (Merck Millipore, Germany). The air mycobiota contained several species of fungi, and almost 1/3 of it was made up of the species of the Aspergillus genus. Sixty-one strains of species other than A. fumigatus were selected for the research purposes, namely: 28 strains of A. ochraceus, 22 strains of A. niger and 11 strains of A. flavus species. Selected fungi underwent a cytotoxicity evaluation with the application of the MTT colorimetric assay (3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide). The assay assesses cell viability by means of reducing the yellow tetrazolium salt to insoluble formazan. A semi-quantitative scale for cytotoxicity grading was adopted: low cytotoxic effect (+) with half maximal inhibitory concentration (IC50) for values ranging from 31.251 cm2/ml to 7.813 cm2/ml, medium cytotoxic effect (++) for values ranging from 3.906 cm2/ml to 0.977 cm2/ml and the high one (+++) for values ranging from 0.488 cm2/ml to 0.061 cm2/ml. The absence of cytotoxicity was determined when the IC50 values was at ≥ 50. RESULTS For 48 samples the analyzed fungi displayed the cytotoxic effect with A. ochraceus in 26 out of 28 cases, with 11 strains displaying the high cytotoxic effect. The lowest cytotoxicity was displayed by fungi of A. niger in 13 out of 22 cases, and the major fungi of A. flavus species were toxic (9 out of 11 cases). CONCLUSIONS A half of the fungi displayed the low cytotoxic effect. On the basis of the comparison of average cytotoxicity levels it was determined that there were significant differences in the levels of cytotoxicity of the analyzed fungi. However, such statement may not provide grounds for a definite conclusion about the compared species of fungi that display a more cytotoxic effect than others. Int J Occup Med Environ Health 2017;30(2):231-239.

Do bacteria isolated from ICU patients ‘ESKAPE’ antibiotic treatment? In vitro susceptibility of the Enterobacteriaceae family to tigecycline

BACKGROUND Enterobacteriaceae are currently causing the majority of healthcare-associated infections (HAI) and simultaneously expressing increasing levels of antibiotic resistance. The purpose of this study is to assess the in vitro sensitivity of MDR strains from the family Enterobacteriaceae to tigecycline in relation to their origin from patients hospitalized in intensive care units (ICUs) and non-ICUs. METHODS The study involved 156 clinically significant strains of the Enterobacteriaceae family isolated from patients with complicated intraabdominal infections (cIAIs) and/or complicated skin and skin structure infections (cSSSIs) hospitalized in ICUs and other surgical departments. Tigecycline MICs were determined by Etest. RESULTS The highest percentage of tigecycline non-susceptible (intermediate + resistant strains) in vitro strains among the Enterobacteriaceae species were observed for Serratia spp. 77.3%, followed by Citrobacter spp. (76.9%) and Enterobacter spp. (70%); whereas K. pneumoniae and E. coli showed 73-73.8% tigecycline susceptibility rates. CONCLUSION Tigecycline demonstrates a high level of antimicrobial in vitro activity when tested against E. coli and K. pneumoniae, even those with the ESBL-phenotype. Tigecycline retained activity against merely 22-30% of Enterobacter, Citrobacter and Serratia genera.

Susceptibility to tigecycline of Acinetobacter baumannii strains isolated from intensive care unit patients

BACKGROUND Infections caused by Acinetobacter baumannii are difficult to cure due to the acquisition of resistance by these bacteria and lead to an increase in the general costs of hospitalization. The aim of this study was to determine tigecycline susceptibility of Acinetobacter baumannii strains isolated from intensive care unit and non-intensive care unit patients with skin and soft tissue infections. METHODS MICs were tested by Etest among 70 Acinetobacter baumannii isolates. RESULTS The MIC range was from 0.5 to 8.0 mg L⁻¹. For ESBL-producing Acinetobacter baumannii, as well as for strains without carbapenemases, the highest MIC to tigecycline value was 8.0 mg L⁻¹. For AmpC-producing Acinetobacter baumannii, the highest MIC to tigecycline value was 6.0 mg L⁻¹ and, for MBL-producing strains, 2.0 mg L⁻¹. CONCLUSIONS The majority of Acinetobacter baumannii strains isolated from ICU and non-ICU patients demonstrated high values of MIC range, MIC50 and MIC90 to tigecycline.