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):459–46

Antimicrobial effect of copper alloys on Acinetobacter species isolated from infections and hospital environment

Abstract Background An increased proportion of Gram-negative bacteria have recently been reported among etiologic agents of infection. In Poland, Acinetobacter baumannii is a big problem for hospitals, especially intensive care units. Touch surfaces made from materials with antimicrobial properties, especially copper alloys, are recommended as a supplementary method of increasing biological safety in the hospital environment. Aim of the study The objective of this study is to determine the susceptibility to selected copper alloys of three clinical Acinetobacter baumannii strains, one Acinetobacter lwoffi and an A. pittii strain isolated from the hospital environment. Material and method The modification of the Japanese Standard, which the ISO 22196:2011 norm was used for testing antimicrobial properties of CuZn37, CuSn6 and CuNi18Zn20 and Cu-ETP and stainless steel as positive and negative control, respectively. Results The highest cidal efficiency, expressed as both time and the degree of reduction of the initial suspension density, against all of the tested Acinetobacter strains was found for ETP copper. But, the results of our study also confirmed effective activity (bacteriocidal or bacteriostatic) of copper alloys selected for the study, contrary to the stainless steel. The reduction in bacterial suspension density is significantly different depending on the strain and copper alloy composition. Conslusions The results of our study confirmed the effective antibacterial activity of copper and its selected alloys against clinical Acinetobacter baumannii and Acinetobacter lwoffii strains, and Acinetobacter pittii strain isolated from the hospital environment

The application of genetics methods to differentiation of three Lactobacillus species of human origin

In recent decades, the interest in probiotics as diet supplements or drugs has increased. In order to determine a specific bacterial isolate to be probiotic, it is necessary to describe precisely its probiotic characteristics and taxonomic properties, including the strain level. Most of the well-known genotyping methods were designed for the commonly-found pathogenic bacteria. The objective of this study is to undertake an attempt at standardization of FISH, RAPD and PFGE methods to genotype and identify the bacteria belonging to Lactobacillus fermentum, L. gasseri and L. plantarum species. The FISH probes have been designed and tested for Lactobacillus fermentum, L. gasseri and L. plantarum species and an endeavor has been made at standardization of RAPD and PFGE methods for these bacterial species. Moreover, the MLST method was applied to differentiate Lactobacillus plantarum strains. L. plantarum isolated from humans could not be genetically diversified with the use of RAPD, PFGE or MLST methods; only the strains originating from plants have displayed diversification among themselves and have been different from the strains of human origin

Antimicrobial resistance in Enterobacterales bacilli isolated from bloodstream infection in surgical patients of Polish hospitals

Background and Aims. Bloodstream infections (BSIs) are one of the most frequently observed hospital-acquired infections (HAIs). We sought to describe the epidemiology and drug resistance secondary Enterobacterales BSIs in surgical patients and check for any correlation with the type of hospital ward. Materials and Methods. This multicenter (13 hospitals in southern Poland) laboratory-based retrospective study evaluated adults diagnosed with BSI secondary to surgical site infection (SSI) hospitalized in 2015–2018; 121 Enterobacterales strains were collected. The drug resistance was tested according to the EUCAST recommendations. Tests confirming the presence of extended-spectrum β-lactamases (ESBLs) and bla resistance genes were carried out. The occurrence of possible clonal epidemics among K. pneumoniae strains was examined. Results. The prevalence of Enterobacterales in secondary BSI was 12.1%; the most common strains were E. coli (n = 74, 61.2%) and Klebsiella spp. (n = 33, 27.2%). High resistance involved ampicillin and ampicillin/sulbactam (92, 8–100%), fluoroquinolones (48–73%), and most cephalosporins (29–50%). Carbapenems were the antimicrobials with the susceptibility at 98%. The prevalence of ESBL strains was 37.2% (n = 45). All the ESBL strains had blaCTX-M gene, 26.7% had the blaSHV gene, and 24.4% had blaTEM gene. The diversity of Klebsiella strains was relatively high. Only 4 strains belonged to one clone. Conclusions. What is particularly worrying is the high prevalence of Enterobacterales in BSI, as well as the high resistance to antimicrobial agents often used in the empirical therapy. To improve the effectiveness of empirical treatment in surgical departments, we need to know the epidemiology of both surgical site infection and BSI, secondary to SSI. We were surprised to note high heterogeneity among K. pneumoniae strains, which was different from our previous experience

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

Antibiotic resistance, ability to form biofilm and susceptibility to copper alloys of selected staphylococcal strains isolated from touch surfaces in Polish hospital wards

Abstract Background Despite the employment of sanitary regimes, contact transmission of the aetiological agents of hospital infections is still exceedingly common. The issue of microbe transmission becomes particularly important when facing multidrug-resistant microorganisms such as methicillin-resistant staphylococci. In the case of deficiencies in cleaning and disinfection procedures, hospital equipment made of copper alloys can play an important role, complementing traditional hospital hygiene procedures. The objective of this study was to characterize staphylococcal strains isolated from touch surfaces in Polish hospital wards in terms of their drug resistance, ability to form biofilm and susceptibility to antimicrobial activity of copper alloys. Methods The materials for the study were 95 staphylococcal strains isolated from touch surfaces in 13 different hospital wards from Małopolska province (the south of Poland). Phenotypic and genotypic antibiotic resistance were checked for erythromycin, clindamycin, gentamycin, ciprofloxacin, trimethoprim/sulfamethoxazole and mupirocin. Biofilm formation ability for the tested strains was checked with the use of culture on Congo red agar. Susceptibility to copper, tin bronze, brass and new silver was tested using a modification of the Japanese standard. Results Over 67% of the analysed staphylococcal strains were methicillin-resistant (MR). Four strains were resistant to all of the tested antibiotics, and 14 were resistant to all except mupirocin. Strains classified as MR had significantly increased resistance to the remaining antibiotic groups. About one-third of the analysed strains revealed biofilm-forming ability. Among the majority of species, biofilm-forming and non-biofilm-forming strains were distributed evenly; in the case of S. haemolyticus only, negative strains accounted for 92.8%. Susceptibility to copper alloys was different between strains and rather lower than in the case of the SA strain selected for comparison. Conclusions Coagulase-negative staphylococci, the most commonly isolated in Polish hospital wards, should not be neglected as an infection risk factor due their high antibiotic resistance. Our experiments confirmed that touch surfaces made of copper alloys may play an important role in eliminating bacteria from the hospital environment