Dorota Romaniszyn

Virulence and Antibiotic Resistance of Pseudomonas aeruginosa Isolated from Patients with Urinary Tract Infections in Southern Poland.

Background: The aim of this study was to analyze the resistance and virulence of Pseudomonas aeruginosa strains causing urinary tract infections in in- and outpatients in Southern Poland. Methods: The study included 83 inpatients and 66 outpatients; 36.9% were female. Results: Monomicrobial infections accounted for 74.5%; polymicrobial infections occurred more frequently among inpatients (odds ratio, OR = 4.32, p = 0.0008). exoS and lasB were detected in 90 and 74% of isolates, respectively. aprA was present in 66%, pilB in 5% and pilA in 23% of isolates. Isolates from adults were more frequently resistant to fluoroquinolones (OR = 0.37, p = 0.029). Twenty-nine isolates were classified as multidrug resistant and 12 as extremely drug resistant, which occurred less frequently in patients <17 years (OR = 0.18, p = 0.024). Nine metallo-β-lactamase-positive isolates were identified. blaSHV was present in 10, blaTEM in 6, blaOXA-10 in 3 and blaVIM-2 in 3 isolates. Conclusion: Antibiotic selection should be based on the knowledge of local antimicrobial susceptibilities to maximize the benefit for patients and minimize the risk of drug resistance.

Bacteria contamination of touch surfaces in Polish hospital wards

BACKGROUND The objective of the study has been to evaluate the pathogenic bacteria contamination of touch surfaces in hospital wards. MATERIAL AND METHODS Samples were taken from frequently touched surfaces in the hospital environment in 13 units of various types. Culturing was carried out on solid blood agar and in growth broth (tryptic soy broth - TSB). Species identification was performed using the analytical profile index (API) biochemical testing and confirmed with matrix assisted laser desorption ionization time-flight mass spectrometry (MALDI-TOF-MS) system. RESULTS The total of 161 samples were taken for the study. Fifty-two of them, after 24 h of culture on a solid medium, demonstrated bacterial growth and further 60 samples had growth after prior multiplication in TSB. Overall, 69.6% of samples exhibited growth of 19 bacterial species. Pathogenic species - representing indicator organisms of efficiency of hospital cleaning - was demonstrated by 21.4% of samples. Among them Acinetobacter spp., Enterocococci spp. and Staphylococcus aureus were identified. Coagulase-negative staphylococci (CNS) were predominant. The proportion of various groups of bacteria significantly varied in respective hospitals, and in various types of wards. Disturbing observation is a large proportion of resistance of isolated CNS strains as a potential reservoir of resistance genes. CONCLUSIONS The results show that touch surfaces in hospital units are contaminated by both potentially pathogenic and pathogenic bacterial species. In connection with the reported, also in Poland, frequent omission or incorrect execution of hand hygiene by hospital staff, and probably patients, touch surfaces still constitute important reservoir of pathogenic bacteria. Improving hand hygiene compliance of health-care workers with recommendations is necessary for increasing biological safety of hospital environment. Med Pr 2017;68(3):459-467.

Virulence Potential of Staphylococcus aureus Strains Isolated from Diabetic Foot Ulcers Among Patients from Southern Poland

The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) was investigated among infected diabetic foot ulcers in hospitalized and nonhospitalized patients in southern Poland to assess the virulence patterns and antimicrobial resistance among these strains. MRSA was detected in 10.3% of all studied isolates, from the hospitalized patients only. The rest of the isolates was methicillin susceptible. The minimal inhibitory concentration that inhibits 50% of bacterial isolates (MIC50) for vancomycin was 1.0 mg/mL. The mupA gene was detected in six (8.8%) isolates, in one MRSA strain and five methicillin-sensitive S. aureus (MSSA) strains. Among the mupA-positive strains, two were resistant to mupirocin (1 MRSA and 1 MSSA). Such results raise serious concern about the usage of mupirocin in MRSA decolonization. The pvl gene was not detected among the study isolates. The majority of isolates (70.6%) possessed the lukE gene, with no significant difference in prevalence between MRSA and MSSA isolates. An interesting finding was the presence of enterotoxin genes among the study isolates. Diabetic foot may therefore be a reservoir of bacteria, containing genes localized on mobile genetic elements that could be easily transferred to other non-pathogenic strains. The prevalence of MRSA was alarmingly high (as also suggested by others), as evaluated by the presence of the mup gene among strains, highlighting the importance of appropriate clinical management of MRSA infections in patients with diabetic foot ulcers. In this group of patients, screening of ulcer samples before antimicrobial therapy would enable informed choices regarding the selection of antimicrobial agents (e.g. octenidine, authorized for the treatment of chronic wounds) maximizing the chances of positive therapy.

Bloodstream Infections due to Enterobacteriaceae Among Neonates in Poland--Molecular Analysis of the Isolates.

Bloodstream infections (BSIs) are associated with a significantly increased risk of fatality. No report has been found about the molecular epidemiology of Enterobacteriaceae causing BSI in neonates in Poland. The aim of this work was to determine the antibiotic resistance profiles, virulence gene prevalence, the epidemiological and genetic relationships among the isolates from Enterobacteriaceae causing BSI in neonates with birth weight < 1501 g. Antimicrobial susceptibility testing was performed. PCR was performed to identify the presence of common beta-lactamase genes, virulence genes. PFGE and MLST were performed. The surveillance group contained 1,695 newborns. The incidence rate for BSIs was 5.9%, the fatality rate 15%. The most common species were Escherichia coli (n = 24) and Klebsiella pneumoniae (n = 16). CTX-M-15 was found in 6 E. coli, 8 K. pneumoniae, 1 Enterobacter cloacae strains. Among E. coli fimH (83.3%), ibeA (37.5%), neuC (20.8%) were the most frequent. PFGE demonstrated unique pulsotypes among E. coli. E. coli ST131 clone was found in 7 E. coli strains. PFGE of 16 K. pneumoniae strains showed 8 pulsotypes. Five isolates from one NICU belonged to one clone. MLST typing revealed 7 different ST with ST336 as the most prevalent. This study provides information about resistance, virulence and typing of Enterobacteriaceae strains causing BSI among neonates. E. coli and Klebsiella spp. isolated in this study have completely different epidemiology from each other.

Virulence and antimicrobial resistance of Staphylococcus aureus isolated from bloodstream infections and pneumonia in Southern Poland

OBJECTIVES Staphylococcus aureus remains the most important cause of infections in hospitals and long-term care facilities. The aim of this study was to analyse the resistance, virulence, and epidemiological and genetic relationships of S. aureus from bloodstream infections (BSIs) and pneumonia from patients in Southern Poland. METHODS All strains were tested for antimicrobial susceptibility using the disk diffusion method. Etest was also performed for vancomycin, teicoplanin, tigecycline, oxacillin, cefoxitin and penicillin. PCR amplification was used to detect selected virulence genes. The genetic similarity of methicillin-resistant S. aureus (MRSA) isolates was determined by spa typing and pulsed-field gel electrophoresis (PFGE). Using the BURP algorithm and the Ridom SpaServer database, spa types were clustered into different clonal complexes (spa-CCs). RESULTS AND CONCLUSIONS MRSA strains were observed at a prevalence of 26.7%, but 88.6% of hospital-acquired infections were MRSA, with no difference between BSIs and pneumonia. The highest resistance was observed to erythromycin and tobramycin. None of the strains were resistant to linezolid, glycopeptides or tigecycline. The strains had no significant virulence factors and the number of virulence genes present did not correlate with the degree of drug resistance. PFGE typing showed relatively high diversity of strains. The majority of isolates belonged to spa type t003 (CC5).

Antimicrobial Properties of Selected Copper Alloys on Staphylococcus aureus and Escherichia coli in Different Simulations of Environmental Conditions: With vs. without Organic Contamination

Background: Hospital equipment made from copper alloys can play an important role in complementing traditional methods of disinfection. Aims of the study: The aim of this study was to assess the dynamics of the antimicrobial properties of selected copper alloys in different simulations of environmental conditions (with organic contamination vs. without organic contamination), and to test alternatives to the currently used testing methods. Materials and Methods: A modification of Japanese standard JIS Z 2801 as well as Staphylococcus aureus (SA) and Escherichia coli (EC) suspended in NaCl vs. tryptic soy broth (TSB) were used in tests performed on seven commonly used copper alloys, copper, and stainless steel. Results: A much faster reduction of the bacterial suspension was observed for the inoculum prepared in NaCl than in TSB. A faster reduction for EC than for SA was observed in the inoculum prepared in NaCl. The opposite results were found for the inoculum based on TSB. A significant correlation between the copper concentration in the copper alloys and the time and degree of bacterial suspension reduction was only observed in the case of EC. Conclusions: This study confirmed the antimicrobial properties of copper alloys, and additionally showed that Staphylococcus aureus was more resistant than Escherichia coli in the variant of the experiment without organic contamination. However, even for SA, a total reduction of the bacterial inoculum’s density took no longer than 2 h. Under conditions simulating organic contamination, all of the tested alloys were shown to have bactericidal or bacteriostatic properties, which was contrary to the results from stainless steel.

acinetobacter baumannii : biofilm production and drug susceptibility isolated from hospital‐acquired infection: biofilm production and drug susceptibility

Acinetobacter baumannii cause opportunistic nosocomial infections and is often multidrug resistant. It has ability to form biofilm. The possession of drug resistance mechanism and ability of biofilm formation seems to be the different way to enhancement of viability in stressful environment. In this study, we evaluate relation between these two factors. The biofilm formation was investigated in M63 medium with casein in microtiter plates, and the drug susceptibility was performed by disk diffusion methods. We found that 80–98% strains formed a biofilm. Strains showing sensitivity to amikacin and tobramycin from ICU produced more biofilm than strains showing resistance to these antibiotics. Ceftazidime‐sensitive strains formed a smaller biofilm than resistant. The logistic regression shows association between drug resistance and strains originating from ICU. In case of ceftazidime, strong biofilm formation and descending from ICU reduced the likelihood of drug sensitivity. For other drugs such as aminoglycosides, fluoroquinolones, trimethoprim/sulfamethoxazole, and tetracycline, we found opposite relation (but it was not statistically significance). However, generally it seems that strong biofilm producers from ICUs are often more susceptible to antibiotics. This situation can be explained by the fact that bacteria protected in biofilm do not need mechanisms responsible for resistance of planktonic cells.

Severe infections caused by multidrug-resistant non-fermentative bacilli in southern Poland

BACKGROUND The impact of multidrug-resistant organisms (MDROs), including non-fermentative bacilli (NFBs), is rising and underestimated, especially in intensive care units (ICUs). The growing prevalence of multidrug resistance (MDR) and extensive drug resistance (XDR) is challenging for clinicians, as the treatment options are limited. OBJECTIVES The purpose of this study was to analyze the extent of the epidemiological problem of multidrugresistant, extensively drug-resistant and pandrug-resistant (PDR) non-fermentative bacilli isolated from pneumonia and bloodstream infections (BSIs) in patients hospitalized in southern Poland. MATERIAL AND METHODS This study included 253 NFBs belonging to Acinetobacter sp. (ACI), Pseudomonas sp. (PAR), and Stenotrophomonas sp. (STM). The microorganisms were identified, and susceptibility testing was performed using a semi-automatic system. The different patterns of resistance were defined as MDR, XDR, or PDR strains. Epidemiological typing of A. baumannii from ICUs was performed by repetitive polymerase chain reaction (rep-PCR). RESULTS More than half of the strains (57.7%) were isolated within ICUs. ACI-strains came significantly more often from ICU wards. The highest prevalence of ACI and PAR was found in pneumonia, whereas STM dominated in BSIs. ACIs were more frequently resistant than other pathogens to all studied antibiotics except colistin (n = 76; 58.9%), and they belonged to the XDR category. DiversiLab demonstrated the presence of 2 dominant clones in the ACI group, both classified as European Clone 2 (EUII). CONCLUSIONS Our results indicate serious potential therapeutic problems related to high antibiotic resistance of ACI isolates. The stratification of drug resistance (MDR/XDR/PDR) may become an important tool for the assessment of public health epidemiology and microbiological hazards at the local, national, and international level. It allows clear presentation of the issues concerning the epidemiology of highly resistant bacilli, and the exchange of information between medical staff and local representatives of public health for the implementation of effective measures to reduce drug resistance.

Urinary tract infections caused by Pseudomonas aeruginos among children in southern Poland

Urinary tract infections (UTIs) are an important cause of morbidity and mortality during the first 2 years of life. Knowledge of the antimicrobial resistance patterns may help clinicians choosing the empirical treatment.

SCCMEC and SPA typing of meticillin resistance Staphylococcus aureus isolated from infections from Southern Poland

The spa gene encodes protein A and is used for typing of methicillin-resistant Staphylococcus aureus, MRSA, such as the mec operon carried by staphylococcal cassette chromosome (SCCmec).