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  • Author: Dagmara Stępień-Pyśniak x
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Urszula Kosikowska, Dagmara Stepien-Pysniak, Dorota Ozga, Andrzej Wernicki and Anna Malm

ABSTRACT

Bacillus spp. can be regarded as a rare component of the nasal mucosa microflora. The aim of this study was to identify Bacillus spp. from the nasal mucosa of healthy adults living in the suburban area near Lublin using the matrix-assisted laser desorptionionization time-of-flight mass spectrometry (MALDI-TOF MS) system.

A total of 11 bacterial isolates from the nasal specimens were cultured. The following species were identified using the routine microbiological methods: Staphylococcus aureus (3 isolates), S. epidermidis (1 isolate), S. intermedius (1 isolate) and Staphylococcus spp. (1 isolate). Moreover, 2 strains of Escherichia coli were isolated. Besides, 3 isolates of Bacillus spp. were found. These isolates were characterized by means of MALDI-TOF MS, resulting in highly specific mass spectral fingerprints and these were identified as B. pumilus, B. safenis and B. licheniformis. It was observed that all studied Bacillus spp. isolates only had the masses in common at 3864 ± 2, 7727 ± 2, and 14301 ± 4. The spectra of B. safensis and B. pumilus showed peaks at m/z 4914 ± 3, 6621 ± 3 and 14291 ± 2, which were absent in the spectrum of B. licheniformis. For B. safenis and B. pumilus, other potential biomarkers could be found at m/z 12620 and 16668, respectively.

Open access

Agnieszka Marek, Ewelina Pyzik, Dagmara Stępień-Pyśniak, Tomasz Hauschild and Tomasz Banach

Abstract

The aim of the study was to identify the affinity of 10 Staphylococcus strains isolated from table chicken eggs to specific species. Preliminary analysis performed by API ID32 Staph test identified these strains as S. aureus, but they exhibited a negative reaction in the tube coagulase test. Thus, the analysed strains were initially characterised as Staphylococcus aureus-like (SAL). Further characterisation was performed by genotypic methods, using restriction fragment length polymorphism (RFLP) of the coagulase gene (coa) and sequencing of the gene rpoB. An attempt was also made to identify the isolated Staphylococcus strains by MALDI-TOF mass spectrometry. The results indicated that none of the strains tested belonged to the species S. aureus. The rpoB sequences of five isolates showed the highest sequence similarity to S. haemolyticus, three isolates to S. chromogenes, and one isolate to S. epidermidis. One strain (SAL4) remained unidentified in this analysis. The results obtained using mass spectrometry were comparable to those based on gene sequence analysis. Strain SAL4, which could not be identified by sequencing, was identified by MALDI-TOF as Staphylococcus chromogenes.

Open access

Sylwia Andrzejczuk, Urszula Kosikowska, Anna Malm, Edyta Chwiejczak and Dagmara Stepien-Pysniak

Abstract

Background. Haemophili are common human microbiota representatives. The aim of our study was to investigate a diversity of Haemophilus spp. isolates selected from clinical specimens on the basis of biochemical characteristics, biotypes distribution, protein profiles and antimicrobial resistance. Results. A total of 893/1025 (87%) of haemophili isolates were identified: 260/1025 (25%) as H. influenzae and 633/1025 (62%) as H. parainfluenzae. Moreover, a group of 107/1025 (10%) isolates without species identification (with e.g. abnormal numerical profile) was described as Haemophilus spp. Within the H. influenzae isolates, biotypes II and III were in a great majority (92/893; 10%, each), whereas among H. parainfluenzae, the most commonly occurring was biotype I and II (301/893, 34% and 178/893, 20%, respectively). A similar prevalence of biotypes was obtained regardless of the patient’s age or health condition or the type of specimen. A production of beta-lactamases was shown in 46/893 (5%) haemophili, both H. influenzae (13/46, 28%) and H. parainfluenzae (33/46, 72%) isolates. On the basis of haemophili biochemical characteristics, the cluster analysis using the UPGMA method demonstrated a high degree of phenotypic similarity due to a small distances between isolates taken from both unhealthy children and adults. Conclusion. Based on biochemical characteristics, about 90% of haemophili clinical isolates representing human-specific respiratory microbiota were positively identified as H. influenzae and H. parainfluenzae. The same differences in biotypes and antimicrobial resistance among isolates selected from healthy people or from patients with chronic and recurrent diseases were detected.

Open access

Ewelina Pyzik, Agnieszka Marek, Dagmara Stępień-Pyśniak, Renata Urban-Chmiel, Łukasz S. Jarosz and Izabella Jagiełło-Podębska

Abstract

Introduction: The study sought to characterise antimicrobial resistance among coagulase-negative Staphylococcus (CNS) species recovered from broiler chickens and turkeys in Poland including the presence of 12 antimicrobial resistance genes and five classical genes of staphylococcal enterotoxins. Material and Methods: A panel of 11 antimicrobial disks evaluated the phenotypic sensitivity of the tested strains to antibiotics. Five multiplex PCR assays were performed using primer pairs for specific detection of antibiotic resistance genes and staphylococcal enterotoxin A to E genes. Results: Selected antimicrobial agent susceptibility testing revealed 100% of such in in vitro conditions to cefoxitin among strains of Staphylococcus sciuri and S. chromogenes. The blaZ (for ß-lactam) and mecA (for methicillin resistance) genes were in 58.3% and 27.5% of strains, respectively. Among genes resistant to tetracyclines, tetK was most frequent. Fewer (CNS) strains showed genes resistant to macrolides, lincosamides, and florfenicol/chloramphenicol. Multiplex PCR for classical enterotoxins (A-E) detected the see gene in two S. hominis strains, while the seb gene producing enterotoxin B was found in one strain of S. epidermidis. Conclusion: CNS strains of Staphylococcus isolated from poultry were either phenotypically or genotypically multidrug resistant. Testing for the presence of the five classical enterotoxin genes showed that CNS strains, as in the case of S. aureus strains, can be a source of food intoxications.