Both biofilm cytotoxicity and monocytes' adhesion may be used as estimators of enterococcal virulence.

Our study aimed to identify markers of enterococci's virulence potential by evaluating the properties of strains of different sites of isolation. Enterococcal strains were isolated as commensals from faeces and as invasive strains from the urine and blood of patients from the University Clinical Centre, Gdansk, Poland. Changes in monocytes' susceptibility to the cytotoxic activity of isolates of different origins and their adherence to biofilm were evaluated using a flow cytometer. The bacterial protein profile was estimated by matrix assisted laser desorption ionization-time of flight mass spectrometer. The cytotoxicity of biofilm and monocytes' adherence to it were the most accurate factors in predicting the prevalence of the strain in the specific niche. Additionally, a bacterial protein with mass-to-charge ratio (m/z) 5000 was found to be responsible for the increased bacterial cytotoxicity, while monocytes' decreased adherence to biofilm was linked with the presence of proteins either with m/z 3330 or 2435. The results illustrate that monocytes' reaction when exposed to the bacterial biofilm can be used as an estimator of pathogens' virulence potential. The observed differences in monocytes' response are explainable by the bacterial proteins' profile. Additionally, the results indicate that the features of both bacteria and monocytes impact the outcome of the infection.

Staphylococcus aureus Co-Infection in COVID-19 Patients: Virulence Genes and Their Influence on Respiratory Epithelial Cells in Light of Risk of Severe Secondary Infection.

Pandemics from viral respiratory tract infections in the 20th and early 21st centuries were associated with high mortality, which was not always caused by a primary viral infection. It has been observed that severe course of infection, complications and mortality were often the result of co-infection with other pathogens, especially Staphylococcus aureus. During the COVID-19 pandemic, it was also noticed that patients infected with S. aureus had a significantly higher mortality rate (61.7%) compared to patients infected with SARS-CoV-2 alone. Our previous studies have shown that S. aureus strains isolated from patients with COVID-19 had a different protein profile than the strains in non-COVID-19 patients. Therefore, this study aims to analyze S. aureus strains isolated from COVID-19 patients in terms of their pathogenicity by analyzing their virulence genes, adhesion, cytotoxicity and penetration to the human pulmonary epithelial cell line A549. We have observed that half of the tested S. aureus strains isolated from patients with COVID-19 had a necrotizing effect on the A549 cells. The strains also showed greater variability in terms of their adhesion to the human cells than their non-COVID-19 counterparts.

Does Salmonella diarizonae 58:r:z53 Isolated from a Mallard Duck Pose a Threat to Human Health?

Salmonella diarizonae (IIIb) is frequently isolated from reptiles and less frequently from birds and mammals. However, its isolation from invasive human infections has not been widely reported. Migratory mallard ducks are excellent bioindicators of pathogen presence and pathogen antibiotic resistance (AMR). We present the first isolation from a mallard duck in central Europe of the antibiotic-resistant Salmonella enterica subsp. diarizonae with the unique antigenic pattern 58:r:z53 and report its whole-genome sequencing, serosequencing, and genotyping, which enabled the prediction of its pathogenicity and comparison with phenotypic AMR. The isolated strain was highly similar to S. diarizonae isolated from humans and food. Twenty-four AMR genes were detected, including those encoding aminoglycoside, fluoroquinolone, macrolide, carbapenem, tetracycline, cephalosporin, nitroimidazole, peptide antibiotic, and disinfecting agent/antiseptic resistance. Six Salmonella pathogenicity islands were found (SPI-1, SPI-2, SPI-3, SPI-5, SPI-9, and SPI-13). An iron transport system was detected in SPI-1 centisome C63PI. Plasmid profile analyses showed three to be present. Sequence mutations in the invA and invF genes were noted, which truncated and elongated the proteins, respectively. The strain also harbored genes encoding type-III secretion-system effector proteins and many virulence factors found in S. diarizonae associated with human infections. This study aims to elucidate the AMR and virulence genes in S. enterica subsp. diarizonae that may most seriously threaten human health.

The Influence of Bacteriophages on the Metabolic Condition of Human Fibroblasts in Light of the Safety of Phage Therapy in Staphylococcal Skin Infections.

Phage therapy has been successfully used as an experimental therapy in the treatment of multidrug-resistant strains of Staphylococcus aureus (MDRSA)-caused skin infections and is seen as the most promising alternative to antibiotics. However, in recent years a number of reports indicating that phages can interact with eukaryotic cells emerged. Therefore, there is a need to re-evaluate phage therapy in light of safety. It is important to analyze not only the cytotoxicity of phages alone but also the impact their lytic activity against bacteria may have on human cells. As progeny virions rupture the cell wall, lipoteichoic acids are released in high quantities. It has been shown that they act as inflammatory agents and their presence could lead to the worsening of the patient's condition and influence their recovery. In our work, we have tested if the treatment of normal human fibroblasts with staphylococcal phages will influence the metabolic state of the cell and the integrity of cell membranes. We have also analyzed the effectiveness of bacteriophages in reducing the number of MDRSA attached to human fibroblasts and the influence of the lytic activity of phages on cell viability. We observed that, out of three tested anti-Staphylococcal phages-vB_SauM-A, vB_SauM-C and vB_SauM-D-high concentrations (109 PFU/mL) of two, vB_SauM-A and vB_SauM-D, showed a negative impact on the viability of human fibroblasts. However, a dose of 107 PFU/mL had no effect on the metabolic activity or membrane integrity of the cells. We also observed that the addition of phages alleviated the negative effect of the MDRSA infection on fibroblasts' viability, as phages were able to effectively reduce the number of bacteria in the co-culture. We believe that these results will contribute to a better understanding of the influence of phage therapy on human cells and encourage even more studies on this topic.

Comparative Assessment of Bacteriophage and Antibiotic Activity against Multidrug-Resistant Staphylococcus aureus Biofilms.

Problems connected with biofilm-related infections and antibiotic resistance necessitate the investigation and development of novel treatment strategies. Given their unique characteristics, one of the most promising alternatives to conventional antibiotics are bacteriophages. In the in vitro and in vivo larva model study, we demonstrate that phages vB_SauM-A, vB_SauM-C, and vB_SauM-D are effective antibiofilm agents. The exposure of biofilm to phages vB_SauM-A and vB_SauM-D led to 2-3 log reductions in the colony-forming unit number in most of the multidrug-resistant S. aureus strains. It was found that phage application reduced the formed biofilms independently of the used titer. Moreover, the study demonstrated that bacteriophages are more efficient in biofilm biomass removal and reduction in staphylococci count when compared to the antibiotics used. The scanning electron microscopy analysis results are in line with colony forming unit (CFU) counting but not entirely consistent with crystal violet (CV) staining. Additionally, phages vB_SauM-A, vB_SauM-C, and vB_SauM-D can significantly increase the survival rate and extend the survival time of Galleria mellonella larvae.

Structure-Activity Relationship of New Chimeric Analogs of Mastoparan from the Wasp Venom Paravespula lewisii.

Mastoparan (MP) is an antimicrobial cationic tetradecapeptide with the primary structure INLKALAALAKKIL-NH2. This amphiphilic α-helical peptide was originally isolated from the venom of the wasp Paravespula lewisii. MP shows a variety of biological activities, such as inhibition of the growth of Gram-positive and Gram-negative bacteria, as well as hemolytic activity and activation of mast cell degranulation. Although MP appears to be toxic, studies have shown that its analogs have a potential therapeutic application as antimicrobial, antiviral and antitumor agents. In the present study we have designed and synthesized several new chimeric mastoparan analogs composed of MP and other biologically active peptides such as galanin, RNA III inhibiting peptide (RIP) or carrying benzimidazole derivatives attached to the ε-amino side group of Lys residue. Next, we compared their antimicrobial activity against three reference bacterial strains and conformational changes induced by membrane-mimic environments using circular dichroism (CD) spectroscopy. A comparative analysis of the relationship between the activity of peptides and the structure, as well as the calculated physicochemical parameters was also carried out. As a result of our structure-activity study, we have found two analogs of MP, MP-RIP and RIP-MP, with interesting properties. These two analogs exhibited a relatively high antibacterial activity against S. aureus compared to the other MP analogs, making them a potentially attractive target for further studies. Moreover, a comparative analysis of the relationship between peptide activity and structure, as well as the calculated physicochemical parameters, may provide information that may be useful in the design of new MP analogs.

A pilot investigation into the influence of electronic cigarettes on oral bacteria.

INTRODUCTION: Electronic cigarettes have already become a popular alternative to traditional smoking. AIM: To observe if there were any changes in oral bacteria of electronic cigarette users. MATERIAL AND METHODS: The study population included 125 patients (40 - e-cigarette users, 43 - cigarette smokers, 42 - non-smokers). The conducted microbiological tests were aimed at identification of microorganisms with potential pathological influence on the oral cavity. Distributions of the study variables were compared between groups with χ2 test. All calculations were carried out with Statistical 10 software (Stat Soft Inc.; Tulsa, USA) and intergroup differences were considered significant at p ≤ 0.05. RESULTS: The differences were statistically significant in relation to Gram-negative bacteria in e-cigarette users (27.5%) compared to smokers of traditional cigarettes (4.6%) (p < 0.05). In relation to Gram-positive bacteria, no statistically significant differences were found between these groups. Co-occurrence of commensal bacteria and potentially pathogenic bacteria from the oral cavity among e-cigarette users was higher than in smokers of traditional cigarettes (32.1% vs. 9.2%; p < 0.05). CONCLUSIONS: The use of e-cigarettes caused changes in oral bacteria compared to smokers of traditional cigarettes and non-smokers especially with respect to colonization of potentially pathogenic bacteria. Changes in the oral cavity environment to the disadvantage of commensal flora can affect the course of some pathological processes in the oral cavity.

Activity of antimicrobial peptides and conventional antibiotics against superantigen positive Staphylococcus aureus isolated from patients with atopic dermatitis.

INTRODUCTION: Staphylococcus aureus causes a diverse array of diseases, ranging from relatively harmless localized skin infections to life-threatening systemic conditions. It secretes toxins directly associated with particular disease symptoms. AIM: To determine the prevalence of methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) colonization among patients with atopic dermatitis and to assess the antimicrobial susceptibility to conventional antibiotics and selected antimicrobial peptides among toxin-producing strains and nonproducing strains. MATERIAL AND METHODS: One hundred patients with atopic dermatitis and 50 healthy people were microbiologically assessed for the carriage of S. aureus. Antimicrobial susceptibility tests were performed using the broth microdilution method for conventional antibiotics and antimicrobial peptides (CAMEL, Citropin 1.1, LL-37, Temporin A). Detection of genes lukS/lukF-PV, tst, sea-sed, eta and etb by multiplex PCR was performed. RESULTS: Staphylococcus aureus strains were isolated from the majority of patients, from either the skin (75%) or the anterior nares (73%). Among the conventional antibiotics tested, the highest rates of resistance were observed for ampicillin, daptomycin, lincomycin and erythromycin. Antimicrobial peptides did not show significant diversity in activity. Among MSSA strains greater differentiation of secreted toxins was observed (sec, eta, pvl, tsst, etb, seb), while in the group of MRSA strains secretion of 3 toxins (pvl, eta, seb) was noted. CONCLUSIONS: Antimicrobial resistance continues to evolve. It is important to monitor S. aureus infections. The profile of toxins produced by S. aureus strains is an important consideration in the selection of an antimicrobial agent to treat infections.

Decolonization of Staphylococcus aureus in patients with atopic dermatitis: a reason for increasing resistance to antibiotics?

INTRODUCTION: Exacerbation of atopic dermatitis can be associated with bacterial infection. The skin of patients is colonized with Staphylococcus aureus in 90% of cases. An attempt has been made to demonstrate that eradication significantly reduces the severity of the disease. Studies indicate the efficacy of topical antibiotics, topical corticosteroids and calcineurin inhibitors. Due to increasing resistance to drugs and the defective antimicrobial peptide profile, decolonization is virtually impossible. AIM: To determine the prevalence of S. aureus colonization among patients with atopic dermatitis and to assess antimicrobial susceptibility of isolated strains to antibiotics, especially fusidic acid and mupirocin. MATERIAL AND METHODS: One hundred patients with atopic dermatitis and 50 healthy subjects were microbiologically assessed for the carriage of S. aureus. Antimicrobial susceptibility tests were performed using the broth-microdilution method for antibiotics: ampicillin, ciprofloxacin, daptomycin, erythromycin, fusidic acid, linezolid, lincomycin, mupirocin, tetracycline and vancomycin. RESULTS: Staphylococcus aureus strains were isolated from the majority of our patients, either from the skin (71%) or the anterior nares (67%). In the present study, 10% of isolations represented methicillin-resistant S. aureus (MRSA). Antibiotics exhibited diverse activities against clinical isolates of S. aureus. Among those tested, the highest rates of resistance were shown for ampicillin - 58.5%, lincomycin - 37.5% and erythromycin - 31.0%. Enhanced resistance levels were expressed to mupirocin (17.5%) and fusidic acid (15.5%). CONCLUSIONS: According to the increasing rate of resistance and quick recolonization after discontinuation of the treatment, chronic use of topical antibiotics is not recommended and should be limited to exacerbation of atopic dermatitis with clinical signs of bacterial infection.

Increasing rate of daptomycin non-susceptible strains of Staphylococcus aureus in patients with atopic dermatitis.

INTRODUCTION: Daptomycin is a cyclic lipopeptide that is bactericidal against Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA), vancomycin-intermediate S. aureus (VISA) and vancomycin-resistant S. aureus (VRSA) strains. Daptomycin exerts its antimicrobial effect by a calcium-dependent interaction with the cytoplasmic membrane resulting in depolarization, ion loss and rapid cell death. Unfortunately, loss of daptomycin susceptibility in S. aureus in the clinical setting has been noted. AIM: To evaluate the susceptibility profile to daptomycin among S. aureus strains isloted from patients with atopic dermatitis (AD). Another point was to correlate the results obtained by broth microdilution method and Etest, which is commonly applied in clinical setting. MATERIAL AND METHODS: One hundred patients with the diagnosis of atopic dermatitis were microbiologically assessed for the carriage of S. aureus. Antimicrobial susceptibility tests were performed using broth-microdilution (BMD) and Etests for daptomycin. RESULTS: Staphylococcus aureus strains were isolated from the majority of our patients, either from the skin (73%) or the anterior nares (75%). Six of the 100 nasal swabs (6%) and 5 of the 100 skin swabs (5%) were positive for methicillin-resistant Staphylococcus aureus (MRSA). A total of 81 of 148 (54.7%) daptomycin non-susceptible isolates of S. aureus were identified by BMD. Only 19 of 81 were also classified as non-susceptible by Etest. CONCLUSIONS: Clinicians and microbiologists should be aware of the possibility of the emergence of daptomycin non-susceptibility (or increase in minimal inhibitory concentration) during prolonged therapy and closely monitor the susceptibility of persisting isolates that might be recovered during therapy.

Poultry-Like pA+ Biotype of Staphylococcus aureus CC346/084 Clone in Human Population.

The aim of the study was (1) to analyse the prevalence of P-like pA+ biotype of S. aureus in material from healthy and diseased individuals, not employed at slaughterhouses or meat processing plants, and (2) to analyse the relatedness of these strains and their genetic variability. The study included 344 strains of Staphylococcus aureus isolated from hospitalized patients with staphylococcal infections and from healthy carriers. The biotypes of S. aureus were determined on the basis of fibrinolysin and ß-haemolysin production, coagulation of bovine plasma, and type of growth on crystal violet agar. Additionally, the strains were tested for the synthesis of protein A in order to distinguish between P-like pA+ and poultry biotypes. Fibrinolysin gene (sak) and methicillin resistance (mecA) were detected by means of PCR. The clonal structure of studied strains was analysed using pulsed field gel electrophoresis and sequencing of spa gene. Finally, the strains were typed with a basic set of 23 bacteriophages. The strains belonging to P-like pA+ biotype corresponded to nearly 20 % of all the studied strains. In contrast to the human biotype, they formed one clonal complex, spa-CC346/084. The P-like pA+ biotype strains did not synthesize fibrinolysin, lacked the sak gene, and showed susceptibility to methicillin. In contrast to the human biotype strains, they belonged mostly to phage group II. The P-like pA+ biotype strains, previously described solely in meat products and meat industry workers, can be also present in hospitalized patients and extra-hospital carriers. These strains form a single, fibrinolysin-negative, clonal complex t084/CC346.

Distribution of toxin genes among different spa types and phage types of animal Staphylococcus aureus.

We analyzed distribution of toxin genes (sea-seo, eta, etb, tst, lukS/lukF-PV) among spa types and phage types of 39 Staphylococcus aureus (S. aureus) isolates from healthy and diseased animals. All isolates turned out to be mecA negative (MSSA). Nine spa types were identified: t144 and t723 (dogs), t084 (dogs and pigs), t5447 (cat), t1491 and t008 (pigs), t002, t127 and t3478 (poultry). Seven phage types were detected, enclosed within four phage groups: I (cat), II (dogs), III (pigs) and mixed group (dogs and pigs). Three poultry spa types proved to be non-typeable by phages. Toxin genes were detected in 33 out of the 39 animal isolates. Our analysis revealed that the incidence of some toxin genes in S. aureus is host specific. Canine isolates t144 of phage group II harbored exfoliative toxin gene (eta), and porcine isolates type t1491 representing phage group III showed enterotoxin A gene (sea). The enterotoxin gene cluster (egc1) and enterotoxin gene seh were found in non-typeable isolates from chicken and in one feline isolate type t5447.

[Differentiation of spa types and staphylococcal cassette chromosome mec (SCCmec) in clinical methicillin-resistant Staphylococcus aureus isolated in medical sites of Gdansk region]. / Zrónicowanie typów spa i kaset SCCmec u klinicznych szczepów Staphylococcus aureus opornych na metycyline izolowanych w osrodkach regionu gdanskiego.

INTRODUCTION: Methicillin-resistant Staphylococcus aureus bacteria are one of the key etiological factors of hospital-acquired and community-acquired infections. MRSA strains have an ability of causing a broad spectrum infections: from a relatively mild skin infections to severe life-threatening systemic infections. They are characterized by multi-drug resistance, virulence of a number of factors, may clonally spread within the hospitals and between hospitals. METHODS: The study embraced a number of 75 isolates of MRSA isolated from patients of 7 medical sites of the Gdansk region within the period of six months (June to December 2013). Strains have derived from various clinical materials, both of hospitalized patients (n=59) and outpatient (n=16). The isolates were tested for the susceptibility to antimicrobial agents accordance with the guidelines EUCAST. To estimate of the variability of occurrence of S. aureus clones used were standard spa gene, consisting in the amplified polymorphic region of the X gene encoding the protein A gene (spa). After receiving the results, a spa types were identified using international database Ridom Spa Server (www.spaserver.ridom.de). To determine the polymorphism cassette carrying the inecA gene from MRSA strains, used typing five major chromosomal cassette SCCmec (I-V) by multiplex PCR. RESULTS: MRSA population genetic analysis carried out on the basis of typing SCCmec cassettes and spa gene has showed a predominance of strains with SCCmec type II casette (46.7%) and SCCmec IV casette (38.7%). Less frequently detected were strains containing SCCmec I cassette (12.0%) and SCCmec III cassette (2.6%). Spa typing revealed the presence of 13 gene types in MRSA. The most frequently observed spa types were: t151 (24.0%), t003 (16.0%) in strains of the SCCmec II cassette and t437 (16.0%) and t008 (14.8%) in the isolates with SCCmec cassette IV, whereas staphylococcus with the type of spa t011 (12.0%) had SCCmec cassette I. CONCLUSIONS: In our population most frequent strains cassette SCCmec II (46.7%), in most representing types of spa t151 (51.4%) and t003 (34.3%), generally resistant not only to ß-lactam antibiotics, but as erythromycin, clindamycin and norfloxacin (82.8%), the more frequently they were isolated from patients than a hospital outpatient centers. The strains SCCmec IV that represent the majority of outpatient centers (68.8%), the most represented type t437 (41.4%) and often occurred in hospital centers.

Phage type 187 as a separate subunit MboI restriction site within the Staphylococcus aureus species.

The aim of this study was to use MboI restriction of pta gene fragment to compare the strains of Staphylococcus aureus phage type 187 and other phage types of S. aureus isolated from humans and dogs, as well as canine S. intermedius group strains. The study included 395 human and canine staphylococcal strains representing S. aureus, S. intermedius, and S. pseudintermedius species. The strains were identified with classic phenotypic methods and by the presence of species-specific thermostable nuclease (nuc SA) gene. All the strains were subjected to the analysis of MboI restriction site of pta gene fragment with PCR-RFLP method. Nearly, all human and animal strains of S. aureus possessed 156- and 164-bp restriction fragments. One of the human strains lacked the 320-bp amplification product. In the case of all S. aureus phage type 187, the amplification product of pta gene was insusceptible to cutting with MboI restrictase. None of S. intermedius strains possessed restriction sites present in the product of amplification of pta gene, while all the strains of S. pseudintermedius had 213- and 107-bp restriction fragments. In conclusion, our findings regarding S. aureus phage type 187 reveal that within the population of strains of S. aureus species, these bacteria represent a group with distinct properties.

Staphylococci isolated from carriage sites and infected sites of dogs as a reservoir of multidrug resistance and methicillin resistance.

The aim of this study was to compare the spread of multidrug-resistant (MDR) and methicillin-resistant (MR) staphylococci in healthy dogs and in dogs with evident symptoms of infection. The samples from 172 healthy and 197 infected dogs were examined. The staphylococci were identified with conventional methods and by means of the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method (MboI). Susceptibility to 15 antibiotics from 10 different antimicrobial classes was tested. Resistance to methicillin was confirmed by the presence of Staphylococcus aureus mecA and S. sciuri mecA genes. Multidrug resistance was defined as resistance to three or more antimicrobial classes. The oral mucosa to be the most frequent site of staphylococcal colonization (55.8 %), followed by nasal cavity (44.2 %), and anus (32.6 %). The prevalence of MDR staphylococci in infected dogs was significantly higher than in the healthy animals (74/137 vs. 34/95, P = 0.006). The MR strains of S. pseudintermedius (2.9 %) originated solely from infected dogs. In contrast, the MR coagulase-negative strains (7.4 %) were isolated solely from healthy dogs. S. aureus strains originated from nasal swabs, MRSA strains were not isolated. MDR staphylococci and MR S. pseudintermedius are more common among infected dogs, but coagulase-negative staphylococci (mostly S. sciuri) seem to be a reservoir of methicillin resistance in healthy dogs.

[Spa types and antibiotic resistance of Staphylococcus aureus bloodstream isolates obtained form patients of the University Clinical Center in Gdansk]. / Typy spa i lekoopornosc szczepów Staphylococcus aureus izolowanych z krwi pacjentów Uniwersyteckiego Centrum Klinicznego w Gdansku.

INTRODUCTION: Staphylococcus aureus is a leading cause of bloodstream infections. For epidemiological investigations of this bacteria spa genotyping is used as the method which has a high discriminatory power and gives results that can be easily compared between laboratories. In contrast to methicillin-resistant S.aureus (MRSA), relatively little is known about spa types among methicillin-susceptible strains (MSSA). We used spa typing and antibiotic resistance patterns analysis for retrospective study of S.aureus bloodstream isolates population from the University Clinical Centre (UCC) in Gdansk. METHODS: The study was performed on 53 isolates from patients of 19 different units/ departments of the UCC. The isolates were tested for the susceptibility to antimicrobial agents. Spa typing was performed on the basis of the sequence analysis of the polymorphic X region of the protein A gene (spa) amplified form the isolates. Spa types were determined by Ridom Staph Type software and were clustered into spa-CCs (clonal complexes) using the algorithm BURP-based upon repeat pattern. MLST (Multilocus Sequence Typing) clonal complexes were predicted from BURP analysis by the Ridom SpaServer database. In MRSA the staphylococcal chromosomal casette (SCC) mec was determined, RESULTS: Spa-typing yielded 26 types. Six spa-CC and seven singletons were identified. The most frequent was spa-CC021involving 38% of isolates. The CC021 consisted of 7 spa types and the most common was t021 corresponding with MLST-CC30. The second frequent was singleton, related to MLST-CC1, with only one type t127. There were 3 MRSA isolates in the population. The MRSA strains were identified as different spa types: t003/ SCCmecII, t008/SCCmecIV and clonally related to MSSA t032/SCCmecIV. No one MRSA strains belonged to spa-CC021. CONCLUSIONS: The spa clonal cluster corresponding with widely distributed among invasive S.aureus strains in Europe MLST-CC30 was found as the most frequent among S.aureus bloodstream isolates from the UCC. Occurrence of spa types which had a genetic background common to well known MRSA clonal lineages was observed.

Changes in the Protein Profile in Staphylococcal Strains from Patients Infected with the SARS-CoV-2 Virus.

Staphylococcus aureus strains are particularly often isolated from patients with SARS-CoV-2 infection. The aim of the current research was to determine whether the SARS-CoV-2 virus infection affects the protein profile of S. aureus. Bacteria were isolated from the forty swabs collected from the patients in the hospitals of the Pomeranian region. MALDI-TOF MS spectra were obtained using a Microflex LT instrument. Twenty-nine peaks were identified. The peak (2,430) is described here for the first time and was unique for the isolates from patients infected with the SARS-CoV-2 virus. These results support the hypothesis of bacterial adaptation to the conditions caused by viral infection.

Intensive poultry farming: A review of the impact on the environment and human health.

Poultry farming is one of the most efficient animal husbandry methods and it provides nutritional security to a significant number of the world population. Using modern intensive farming techniques, global production has reached 133.4 mil. t in 2020, with a steady growth each year. Such intensive growth methods however lead to a significant environmental footprint. Waste materials such as poultry litter and manure can pose a serious threat to environmental and human health, and need to be managed properly. Poultry production and waste by-products are linked to NH3, N2O and CH4 emissions, and have an impact on global greenhouse gas emissions, as well as animal and human health. Litter and manure can contain pesticide residues, microorganisms, pathogens, pharmaceuticals (antibiotics), hormones, metals, macronutrients (at improper ratios) and other pollutants which can lead to air, soil and water contamination as well as formation of antimicrobial/multidrug resistant strains of pathogens. Dust emitted from intensive poultry production operations contains feather and skin fragments, faeces, feed particles, microorganisms and other pollutants, which can adversely impact poultry health as well as the health of farm workers and nearby inhabitants. Fastidious odours are another problem that can have an adverse impact on health and quality of life of workers and surrounding population. This study discusses the current knowledge on the impact of intensive poultry farming on environmental and human health, as well as taking a look at solutions for a sustainable future.

Outbreak of bullous impetigo caused by Staphylococcus aureus strains of phage type 3C/71 in a maternity ward linked to nasal carriage of a healthcare worker.

We describe an outbreak of bullous impetigo (BI) that occurred in a maternity unit and show phenotypic and genotypic properties and relatedness of isolated Staphylococcus aureus strains. Clinical material was obtained from 11 affected neonates. Additionally, nasal swabs from 67 healthy care workers (HCWs) as well as 107 environmental swabs were investigated. All isolates were screened for exfoliative toxin genes (eta, etb), antibiotic susceptibility and phage typed. Chromosomal DNA was genotyped by MLVF method and PCR/RFLP of coagulase gene were tested. Affected neonates were infected by two clusters of eta-positive S. aureus of phage type 3C/71: (1) MLVF type A isolates resistant only to penicillin, and (2) MLVF type B isolates resistant to penicillin and erythromycin/clindamycin. All isolates were susceptible to methicillin. We found 19 of 67 HCWs to be S. aureus nasal carriers. Two nasal isolates from HCWs were related to the outbreak on the basis of phage typing, PCR detection of eta/etb genes, antibiotyping and genotyping. Additionally, environmental swabs from the maternity unit revealed a 3C/71 S. aureus in the mattress of a baby bed. This is the first documented case of an outbreak of BI caused by phage type 3C/71 eta-positive strain of S. aureus.

Activity of Phage-Lactoferrin Mixture against Multi Drug Resistant Staphylococcus aureus Biofilms.

Biofilms are complex bacterial structures composed of bacterial cells embedded in extracellular polymeric substances (EPS) consisting of polysaccharides, proteins and lipids. As a result, biofilms are difficult to eradicate using both mechanical methods, i.e., scraping, and chemical methods such as disinfectants or antibiotics. Bacteriophages are shown to be able to act as anti-biofilm agents, with the ability to penetrate through the matrix and reach the bacterial cells. However, they also seem to have their limitations. After several hours of treatment with phages, the biofilm tends to grow back and phage-resistant bacteria emerge. Therefore, it is now recommended to use a mixture of phages and other antibacterial agents in order to increase treatment efficiency. In our work we have paired staphylococcal phages with lactoferrin, a protein with proven anti-biofilm proprieties. By analyzing the biofilm biomass and metabolic activity, we have observed that the addition of lactoferrin to phage lysate accelerated the anti-biofilm effect of phages and also prevented biofilm re-growth. Therefore, this combination might have a potential use in biofilm eradication procedures in medical settings.