Flies as a potential vector of selected alert pathogens in a hospital environment.

Multi-drug resistant pathogens are a global problem. Flies are a potential vector of multi-drug resistant pathogens, which can be particularly dangerous in the hospital environment. This study aimed to evaluate flies as vectors of alert pathogens. The research material consisted of 100 flies (Musca domestica (46.0%), Lucilia sericata (28.0%), and Calliphora vicina (26.0%)) collected at the University Hospital No. 1 dr. A. Jurasz in Bydgoszcz (Poland) in 2018-2019 (summer months). The presence of bacteria of the genera: Enterococcus, Staphylococcus, Escherichia, Leclercia, Citrobacter, Hafnia, Providencia, Proteus, Enterobacter, Klebsiella, Raoultella, Morganella, Moellerella, Bordetella, Pantoea, Serratia, Plesiomonas, Wohlfahrimonas, and Lelliottia was confirmed. The most frequently isolated species included: Enterococcus faecalis (n = 64), Escherichia coli (n = 43) and Moellerella wisconsensis (n = 24). The infection rate and antibiotic resistance of bacteria were assessed. One strain of Proteus mirabilis (isolated from Calliphora vicina) produced ESBLs (extended-spectrum beta-lactamases). The infection rate was 0.38%, 0.26%, and 0.20% for Musca domestica, Lucilia sericata, and Calliphora vicina, respectively. The flies from a hospital area were not a vector of alert pathogens. Monitoring flies as potential vectors of pathogens is an important aspect of public health, especially for hospitalized patients.

Influence of Selected Factors on Biofilm Formation by Salmonella enterica Strains.

Biofilm formed by S. enterica on the surface of gallstones or biomaterials promotes the development and spread of chronic infection. The aim of the study was to assess biofilm formation on the surface of polystyrene depending on nutritional conditions and the effect of 0.5, 1.0, and 2.0% glucose and 3.0% bile and sub-inhibitory concentrations of ampicillin on biofilm formation of S. enterica. Sixty-nine clinical strains of S. enterica isolated from feces (92.8%) and blood (7.2%) collected from patients (66.7%) and carriers (33.3%) were used in the study. Assessment of forming 24-h biofilm by these strains was performed on the surface of polystyrene 96-well plates at 37 °C. In this study, it was indicated that 1.0% glucose and 3.0% bovine bile inhibit biofilm formation. Biofilm formation was inhibited in all examined sub-MIC of ampicillin. Biofilm formation is varied in different conditions, depending on the serovar.

Vitamin C in the Presence of Sub-Inhibitory Concentration of Aminoglycosides and Fluoroquinolones Alters Proteus mirabilis Biofilm Inhibitory Rate.

Vitamin C has antimicrobial activity and is often used as an oral supplement accompanying antibiotic treatment in urinary tract infections (UTI). Proteus mirabilis is the third common species responsible for UTIs that are mostly treated with fluoroquinolones or aminoglycosides. Treatment of the UTI caused by P. mirabilis is problematic due to the ability to form biofilm on the urinary catheters. The aim of the study was to evaluate the influence of ascorbic acid in combination with antibiotics on P. mirabilis abilities to form biofilm. The susceptibility of P. mirabilis reference strain ATCC® 29906™ and four clinical strains isolated from the urine samples of patients with urinary catheter were evaluated according to EUCAST recommendations. The influence of ascorbic acid (0.4 mg × mL-1) in combination with antibiotics on biofilm formation was evaluated spectrophotometrically. Aminoglycosides at sub-inhibitory concentrations more successfully limited biofilm formation by P. mirabilis strains without ascorbic acid addition. Inhibition rate differences at the lowest concentrations of gentamicin and amikacin were statistically significant (p ≤ 0.05). Ascorbic acid addition to the culture medium limited the inhibitory effect of fluoroquinolones, facilitating biofilm formation by P. mirabilis strains. The addition of ascorbic acid during aminoglycosides therapy may disturb treatment of urinary tract infections related to the presence of P. mirabilis biofilm.

Biocidal Effectiveness of Selected Disinfectants Solutions Based on Water and Ozonated Water against Listeria monocytogenes Strains.

The aim of this study was to compare the biocidal effectiveness of disinfectants solutions prepared with ozonated and non-ozonated water against Listeria monocytogenes. Six L. monocytogenes strains were the research material (four isolates from food: meat (LMO-M), dairy products (LMO-N), vegetables (LMO-W), and fish (LMO-R); one clinical strain (LMO-K) and reference strain ATCC 19111). The evaluation of the biocidal effectiveness of disinfectant solutions (QAC-quaternary ammonium compounds; OA-oxidizing agents; ChC-chlorine compounds; IC-iodine compounds; NANO-nanoparticles) was carried out, marking the MBC values. Based on the obtained results, the effectiveness coefficient (A) were calculated. The smaller the A value, the greater the efficiency of disinfection solutions prepared on the basis of ozonated versus non-ozonated water. Ozonated water showed biocidal efficacy against L. monocytogenes. Among tested disinfectentants, independent on type of water used for preparation, the most effective against L. monocytogenes were: QAC 1 (benzyl-C12-18-alkydimethyl ammonium chlorides) (1.00 × 10-5-1.00 × 10-4 g/mL) in quaternary ammonium compounds, OA 3 (peracetic acid, hydrogen peroxide, bis (sulphate) bis (peroxymonosulfate)) (3.08 × 10-4 -3.70 × 10-3 g/mL) in oxidizing agents, ChC 1 (chlorine dioxide) (5.00 × 10-8 -7.00 × 10-7 g/mL) in chlorine compounds, IC 1 (iodine) (1.05-2.15 g/mL) in iodine compounds, and NANO 1 (nanocopper) (1.08 × 10-4 - 1.47 × 10-4 g/mL) in nanoparticles. The values of the activity coefficient for QAC ranged from 0.10 to 0.40, for OA-0.15-0.84, for ChC-0.25-0.83, for IC-0.45-0.60, and for NANO-0.70-0.84. The preparation of disinfectants solution on the basis of ozonated water, improved the microbicidal efficiency of the tested disinfectant, especially the quaternary ammonium compounds. An innovative element of our work is the use of ozonated water for the preparation of working solutions of the disinfection agents. Use ozonated water can help to reduce the use of disinfectant concentrations and limit the increasing of microbial resistance to disinfectants. This paper provides many new information to optimize hygiene plans in food processing plants and limit the spread of microorganisms such as L. monocytogenes.

Comparison of the effectiveness of dipping agents on bacteria causing mastitis in cattle.

INTRODUCTION: Mastitis may result in physical, chemical and microbiological changes in milk and pathological lesions in the glandular tissue. Milk derived from cows with mastitis may become a cause of infections in humansw and animals. OBJECTIVES: The aim of this study was to assess the effectiveness of selected dipping agents in the inactivation of several bacteria that may cause mastitis in cattle. MATERIAL AND METHODS: Three strains of each of the following species: Escherichia coli, Klebsiella pneumoniae, Serratia marcescens, Staphylococcus aureus and Listeria monocytogenes, isolated from milk, were used in the study. Identification of isolates was carried out using the automatic system VITEK2 Compact. Evaluation of the genetic similarity between the tested strains was made using the RAPD technique. Drug susceptibility of strains was evaluated with the disc diffusion method. Assessment of the effectiveness of iodine, stabilized iodine, povidone iodine and chlorhexidine was performed using fragments of skin from cow teats. RESULTS: All the tested strains were genetically different. Most of them were susceptible to the studied antibiotics. Only two strains of L. monocytogenes were resistant to all the studied antibiotics. The percentage rate of reduction in the number of bacteria after using of dipping agents was very high (>90%). The most susceptible to the dipping preparations used were L. monocytogenes (99.6 - 99.9%). Stabilized iodine was the most effective dipping agent for all tested bacteria, causing a reduction rate in the number of bacteria from 99.80% (E. coli) - 99.99% (S. aureus, L. monocytogenes). CONCLUSIONS: The results obtained may contribute to a reduction in udder infections in cows, especially mastitis, and improve the quality of the milk.

[High level of aminoglycoside resistance among Enterococcus faecalis and Enterococcus faecium strains]. / Opornosc na wysokie stezenia aminoglikozydów wsród szczepów Enterococcus faecalis i Enterococcus faecium wyosobnionych z materialu klinicznego.

Enterococcus sp. strains are believed as important reason of serious nosocomial infections currently. These infections are cured by using combination of beta-lactams and aminoglycosides for their treatment. Enterococcus sp. resistant to high-level doses of aminoglycosides, beta-lactams and vancomycin are responsible for therapeutic failure. The aim of our study was to evaluate the incidence of isolation and susceptibility to antibiotics of HLAR Enterococcus sp. strains isolated between 2007 and 2010 from the patients of University Hospital No. 1 of dr A. Jurasz Collegium Medicum of L. Rydygier in Bydgoszcz Nicolaus Copernicus University in Torun. Amongst 6137 Enterococcus sp. strains 1124 (18,3%) presented HLAR phenotype; 53,1% of them was identified as E. faecalis and 46,9% as E. faecium. The highest percentage of all examined strains was isolated from the patients of different surgery clinics, Intensive Care Units, and Pediatrics, Hematology and Oncology Clinic. HLAR and HLSR phenotypes were noted in E. faecalis, for 45,7% and 27,5% strains, in E. faecium - 29,8% and 9,5%, respectively. HLGR phenotype was presented twice more often in E. faecium than E. faecalis. Highest percentages of E. faecium resistant to glycopeptides and rifampicin were observed when compared with E. faecalis. The highest percentages of strains intermediate, resistant to vancomycin and resistant to glycopeptides were noted for E. faecium strains with phenotypes HLAR, HLGR and HLSR.

[Susceptibility to antifungal agents of Candida sp. and biofilm formation]. / Lekowrazliwosc a zdolnosc tworzenia biofilmu przez Candida sp.

In recent years the increase in frequency of fungal infections with Candida sp. was noticed. These infections are connected with ability of Candida sp. to form biofilm on surfaces of biomaterials used in medicine. Furthermore fungal infections make serious therapeutic problems because ofbiofilm resistance to antifungal agents actually. The aim of the study was to evaluate the susceptibility to antifungal agents of Candida sp. and their ability to form biofilm on different biomaterials. 50 strains of Candida sp. isolated from patients of University Hospital No. 1 of dr A. Jurasz in Bydgoszcz were examined. API Candida (bioMérieux) tests were used to identify Candida sp. strains. The susceptibility of the yeast strains to antifungal agents was evaluated by ATB FUNGUS 2 INT (bioMérieux) tests. The susceptibility of examined strains to voriconazole, posaconazole, caspofungin and anidulafungin was assessed by means ofEtests (AB BIODISK) method employing drug concentrations from 0,002 to 32 microg/ml. All analysed strains were susceptible to amphotericin B and caspofungin. Biofilm formation on different biomaterials (silicon, latex, polychloride vinyl, polypropylene, nylon) was measured after 72 hour incubation at 37 degrees C. All examined yeasts formed biofilm on all analysed biomaterials. The highest number of strains formed biofilm on surface of polychloride vinyl: 23 (92,0%) by C. albicans strains and 24 (96,0%) Candida non-albicans strains. The lowest number of the strains formed biofilm on the surface of nylon: 12 (48,0%) of C. albicans strains and 9 (36,0%) of Candida non-albicans strains. The studied strains resistant to azoles and anidulafungin display stronger ability to form biofilm on surfaces of all analysed biomaterials.

[Evaluation of the API ZYM system and RPMI agar plates supplemented with Tween 40 for detection of lipolytic enzymes of Candida spp]. / Ocena przydatnosci testu API ZYM i podloza RPMI wzbogaconego w Tween 40 do wykrywania lipolitycznych enzymów Candida sp.

Lipolytic activity of 40 strains of Candida spp. was tested on API ZYM system and on RPMI agar plates supplemented with 1% Tween 40. Lipolytic activity was indicated by opaque zones around the inoculum cylindrical holes were punched in the medium. Clearing of the medium around the bacterial colonies indicated that an isolate produce lipase. Only 4 (21.1%) strains of C. albicans, and 3 (14.1%) strains of non-C. albicans which hydrolyzed 2-naftylomirystylan by use of the API ZYM system was observed. In contrast, 16 (78.9%) strains of C. albicans and 17 (80.7%) strains of non-C. albicans produced lipases on the agar plate using RPMI agar plates supplemented with 1.0% Tween 40. Determination oflipase activities with the API ZYM system were in no agreement with lipase tests in RPMI supplemented with Tween 40. Our study verify greater usefulness of RPMI supplemented with Tween 40 for detection of lipolytic enzymes of Candida species in comparison to the API ZYM.

[Salmonella spp. strains resistant to drugs]. / Szczepy Salmonella sp. oporne na leki przeciwbakteryjne.

The aim of the study was retrospective analysis of Salmonella spp. strains isolated from patients of State Infectious Diseases Observatory Hospital of T. Browicz in Bydgoszcz (SZAK) and University of dr. A. Jurasz in Bydgoszcz (SU CM UMK) in 2006-2009. The percentages of Salmonella spp. strains resistant to at least one drug were: 19,0% in 2006, 12,5% in 2007, 50,6% in 2008 and 43,8% in the first half of 2009 year. The highest number of Salmonella spp. strains resistant to drugs were isolated from stool (96,7%) and from patients of SZAK (83,3%). Among all isolated Salmonella spp. strains resistant to drugs the highest percentage were S. enterica serovar Enteritidis (56,7%). Among S. enterica bacilli predominated resitant phenotypes to ampicillin, amoxicillin, chloramphenicol and nalidixic acid. The increasing number of strains resistant to ciprofloxacin (0,0 - 26,7%) and high percentage of strains resistant to nalidixic acid (97,3%) were noted. Decreasing resistance to chloramphenicol was observed in our study (54,5 - 14,3%).

[Frequency of isolation and susceptibility to antibiotics of Escherichia coli strains isolated from blood]. / Czestosc izolacji i lekoopornsc szczepów Escherichia coli wyosobnionych z krwi.

The aim of our study was the analysis of Escherichia coli strains obtained from patients of University Hospital No 1 of dr A. Jurasz Collegium Medicum of L. Rydygier in Bydgoszcz Nicolaus Copernicus University in Torun and State Infectious Diseases Observatory Hospital of T. Browicz in Bydgoszcz, between 2007 and 2010. Among all microorganisms isolated from blood was 8.7% E. coli strains and 45.1% of all rods from Enterobacteriaceae family. Number of E. coli isolations from positive blood samples was: 64 in 2007, 69 in 2008, 77 in 2009 and 26 in the first half of 2010 year. The highest percentage of E. coli strains were obtained from patients of the Transplantology and Surgery Clinic (16.1%), the Nephrology and Internal Diseases Clinic with the Dialysis Centre (14.0%), the Pediatric, Hematology and Oncology Clinic (13.6%) and the Anesthesiology and Intensive Care Clinic (13.6%). All analysed strains were susceptible to carbapenems, amikacin and tygecycline. The highest percentage of resistant strains were observed to ampicillin (70.7%), piperacillin (43.9%), tetracycline (42.8%) and doxycycline (38.8%). During four years of study 4 (6.3%), one, three and two E. coli strains with ESBL were isolated, respectively.

[Influence of ciprofloxacin on the ability of production of staphylococcin T in Staphylococcus cohnii (StT)]. / Wplyw ciprofloksacyny na zdolnosc wytwarzania stafylokokcyny T Staphylococcus cohnii (StT).

The aim of this study was to evaluate the influence of ciprofloxacin in a concentration of 0.25 microg/ml on the ability of synthesis of staphylococcin T (StT) Staphylococcus cohnii at 37 degrees C after 24 and 48 hours incubation. Ciprofloxacin in concentration of 0.25 microg/ml after 24 hours incubation inhibits antistaphylococcal activity StT produced by S. cohnii, while after 48 hour incubation, S. cohnii StT is excreted on the same level, in the presence and in the absence of ciprofloxacin.

[The drug susceptibility of penicillin-resistant Streptococcus pneumoniae]. / Lekowrazliwosc Streptococcus pneumoniae opornych na penicyline.

The aim of our study was to evaluate a frequency of isolation and susceptibility to antibiotics of Streptococcus pneumoniae penicillin resistant among 154 strains S. pneumoniae isolated between 2003 and 2006 in University Hospital of Dr. A. Jurasza in Bydgoszcz. Antimicrobial susceptibility was assessed by disc-diffusion method according to the guidelines of Clinical and laboratory Standards Institute and The national Reference Centre for Antimicrobial Susceptibility. Minimal inhibitory concentrations for penicillin and cefotaxime were assessed by E-test method. Study shows increasing isolation of SPPR strains from 8,2% in 2003 to 32,0% in 2006. Strains were mostly isolated from patients ofNeurosurgery and Neurotraumatology Clinic and Rehabilitation Clinic. SPPR strains were mainly isolated from respiratory tract. Over 68% of SPPR showed intermediate resistance to penicillin and 73,3% of strains were susceptible to cefotaxime. Between 2003 and 2006 increased percentage of resistance strains to erythromycin, tetracycline and sulphometoxasol.

[Influence of staphylococcin T on Enterococcus sp. growth]. / Oddzialywanie stafylokokcyny T na wzrost Enterococcus sp.

Bacteriocins are ribosomally synthesised, extracellular bacterial products. Generally, spectrum of inhibition is limited to the same or closely related species to bacteriocin producer. Staphylococcin T is produced by Staphylococcus cohnii strain. The present study concerns influence of StT to 267 Enterococcus sp. strains growth isolated between 2003 and 2006 in Department of Microbiology University Hospital of dr. A. Jurasz in Bydgoszcz. S. cohnii T antagonistic ability evaluated towards bacteries on Mueller-Hinton Agar (bio Mérieux) in aerobic conditions. After 24 and 48 hours tested enterococci suspensions were plated perpendiculary. Susceptibility to antibiotics was assessed by disc diffusion method according to the guideless of Clinical and Laboratory Standards Institute and National Reference Centre for Antimicrobial Susceptibility. Among Enterococcus sp. strains tested 7.1% were sensitive to StT. The highest percentage of sensitive enterococci isolated from wound swabs, urine, blood and pus. Enterococcus faecium strains dominated (63.2%) among enterococci sensitive to StT. Moderate inhibition degree on S. cohnii T bacteriocin action was observed in majority sensitive enterococci strains. Enterococcus sp. sensitive to StT strains were frequently multidrug resistant (68.4%). According to the study results and increasing resistance to antibiotics, StT could be an alternative agent used to treat infections caused by Enterococcus sp.