Virulence analysis and antibiotic resistance of Klebsiella pneumoniae isolates from hospitalised patients in Poland.

Klebsiella pneumoniae (KP) is a nosocomial pathogen causing difficult-to-treat infections. The presence of virulence genes and antibiotic resistance of 109 KP isolates from hospitalized patients were investigated. Among them, 68.8% were multi-drug resistant (MDR) and 59.6% produced extended-spectrum beta-lactamases (ESBLs). Metallo-ß-lactamases (MBLs) were produced by 22% of isolates (mainly from anus), including 16.5% of isolates producing New Delhi metallo-ß-lactamase (NDM-1). The genes encoding adhesins (fimH-91.7%, mrkD-96.3%), enterobactin (entB-100%) and yersiniabactin (irp-1-88%) were frequently identified. The genes encoding salmochelin (iroD-9.2%, iroN-7.3%) and colibactin (clbA, clbB-0.9%) were identified rarely. Iron acquisition system-related kfu gene and wcaG gene involved in capsule production were identified in 6.4% and 11% of isolates, respectively. The rmpA gene associated with hypermucoviscosity was present in 6.4% of isolates. In 19.2% of isolates magA gene was detected, specific for K1 capsule serotype, while 22.9% of isolates showed K2 capsule serotype. The rmpA, iroD or iroN genes being diagnostic biomarkers for hypervirulent KP (hvKP) were detected in 16.5% of isolates. We found that 55.5% of hvKP were MDR and produced ESBLs, thus hospital KP isolates pose a serious threat to the healthcare system.

The prevalence of virulence determinants in methicillin-resistant Staphylococcus aureus isolated from different infections in hospitalized patients in Poland.

Methicillin-resistant Staphylococcus aureus (MRSA) is responsible for hard-to-treat infections. The presence of 19 virulence genes in 120 MRSA isolates obtained from hospitalized patients and genetic relationships of these isolates were investigated. The eno (100%) and ebps (93.3%) genes encoding laminin- and elastin binding proteins, respectively, were ubiquitous. Other adhesion genes: fib (77.5%), fnbB (41.6%), bbp (40.8%), cna (30.8%) encoding proteins binding fibrinogen, fibronectin, bone sialoprotein and collagen, respectively, and map/eap (62.5%), encoding Eap, were also frequent. The etB and etD genes, encoding exfoliative toxins, were present in 15.6% and 12.5% isolates, respectively. The splA, splE and sspA, encoding serine protease were detected in 100%, 70.8% and 94.2% isolates, respectively. The tst gene, encoding toxic shock syndrome toxin-1 was found in 75% isolates. The cna, map/eap and tst genes were the most common in wound isolates and much less common in blood isolates. We identified 45 different spa types, t003 (21.7%) and t008 (18.8%) being the most common. The t003 was the most frequent among isolates from the respiratory tract (35.5%), while t008 in blood isolates (40%). Identification of virulence factors of MRSA is important for evaluation of pathogen transmission rate and disease development.

Antibiotic Resistance of Uropathogens Isolated from Patients Hospitalized in District Hospital in Central Poland in 2020.

The aim of this study was to determine antibiotic resistance patterns and the prevalence of uropathogenes causing urinary tract infections (UTIs) in patients hospitalized in January-June 2020 in central Poland. Antimicrobial susceptibility testing was performed using the disk-diffusion method. Escherichia coli (52.2%), Klebsiella pneumoniae (13.7%), Enterococcus faecalis (9.3%), E. faecium (6.2%), and Proteus mirabilis (4,3%) were most commonly isolated from urine samples. E. coli was significantly more frequent in women (58.6%) (p = 0.0089) and in the age group 0-18, while K. pneumoniae was more frequent in men (24.4%) (p = 0.0119) and in individuals aged 40-60 and >60. Gram-negative species showed resistance to ampicillin. K. pneumoniae were resistant to amoxicillin plus clavulanic acid (75.0%), piperacillin plus tazobactam (76.2%), cefotaxime (76.2%), cefuroxime (81.0%), ciprofloxacin (81.0%), and trimethoprim plus sulphamethoxazole (81.0%). Carbapenems were effective against all E. coli and P. mirabilis. Some K. pneumoniae (13.6%) produced metallo-ß-lactamases (MBLs). E. coli (22.6%), K. pneumoniae (81.8%), and all E. faecium were multidrug-resistant (MDR). Some E. coli (26.2%), K. pneumoniae (63.6%), and P. mirabilis (14.3%) isolates produced extended-spectrum beta-lactamases (ESBL). Vancomycin-resistant E. faecium was also found. This study showed that the possibilities of UTIs therapy using available antibiotics become limited due to the increasing number of antibiotic-resistant uropathogens.

Antimicrobial Resistance Patterns in Methicillin-Resistant Staphylococcus aureus from Patients Hospitalized during 2015-2017 in Hospitals in Poland.

OBJECTIVE: The aim of this study was to determine antimicrobial resistance profiles of methicillin-resistant Staphylococcus aureus (MRSA) isolates from clinical samples from patients hospitalized during 2015-2017 in hospitals of -Masovian district in Poland. MATERIALS AND METHODS: Antimicrobial resistance of 112 MRSA isolates was tested with a disc diffusion method. Isolates were examined for methicillin resistance using a 30 µg cefoxitin disk. Resistance was confirmed by PCR detection of the mecA gene. PCR was also used to determine spa gene polymorphism in X-region. RESULTS: A large number of MRSA isolates showed resistance to levofloxacin (83.9%), ciprofloxacin (83%), erythromycin (77.7%) and clindamycin (72.3%). A lower number of MRSA isolates showed resistance to tetracycline (10.7%), amikacin (14.2%), gentamicin and trimethoprim with sulfamethoxazole (8.0%). None of the MRSA isolates were resistant to linezolid and teicoplanin. Among MRSA isolates, 92.9% were multidrug-resistant (MDR). Resistance to erythromycin, clindamycin, ciprofloxacin and levofloxacin was the most common resistance pattern among MDR MRSA isolates. The highest number of isolates was resistant to 4 groups of antimicrobials (53.8%). The number of drugs to which MRSA isolates were resistant in 2017 was significantly higher than that in 2016 (p = 0.002). The size polymorphism analysis of X fragment of the spa gene revealed high genetic diversity of the investigated group MRSA isolates. CONCLUSION: This study demonstrates that in the hospital environment, MRSA isolates can quickly acquire new antimicrobial resistance determinants and that knowledge of current resistance patterns is important for the effective treatment of infections caused by MDR MRSA.

Biofilm Formation by Methicillin-Resistant and Methicillin-Sensitive Staphylococcus aureus Strains from Hospitalized Patients in Poland.

Biofilm-mediated infections in the hospital environment have a significant negative impact on patient health. This study aimed to investigate biofilm production in vitro and the presence of icaABCD genes in methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) strains isolated from hospitalized patients. MRSA (73) and MSSA (57) strains were evaluated for biofilm production by the microtiter plate method. The presence of ica operon was investigated by PCR. Out of 130 strains, 99.2% were biofilm producers. Strong biofilms were formed by 39.7% of MRSA and 36.8% of MSSA strains. The highest percentage of strong biofilm producers was found among the strains isolated from sputum and tracheostomy tube (66.7%), nose and catheter (50%), throat (44.4%), and bronchoalveolar washings (43.8%). The strains isolated from bronchoalveolar washings produced significantly more biofilm than strains isolated from wound and anus. The ability of biofilm forming by fecal strains was significantly lower compared to strains from other materials. MRSA strains had significantly higher ability of biofilm formation than MSSA strains (P = 0.000247). The presence of ica operon in MRSA was detected in all strains. Comparison of strong biofilm biomass of the strains with icaABCD, icaABD, and icaAD revealed that strains with icaABCD and icaABD produced highly significantly more biofilm than strains with icaAD. Biofilm forming by both MRSA and MSSA strains indicates high ability of theses strains to persist in hospital environment which increases the risk of disease development in hospitalized patients.

The effects of selected phytochemicals on biofilm formed by five methicillin-resistant Staphylococcus aureus.

The aim of this study was to evaluate the ability of 0.1% thyme oil (TO), trans-cinnamaldehyde (TC), ferulic acid (FA), p-coumaric acid (p-CA), caffeic acid (CA), lavender essential oil (LO), geranium essential oil (GO) and tee tree oil (TTO) to control biofilms formed by methicillin-resistant Staphylococcus aureus (MRSA) strains. Depending on the strains, TO reduced 59.7-85% of biofilm mass, while TC 52.9-82.4% after 48 h of treatment. Reduction of metabolic activity of biofilms in ranges 79.3-86% and 85.9-88.7% was observed after 48 h of TC and TO of treatment, respectively. In the case of some strains, reduction of biofilm mass in the presence of FA, CA, GO, LO and TTO was not observed. This study showed that TO and TC might have therapeutic potential as an inhibitory agents for use in MRSA biofilm-related infections.

Virulence factors, biofilm-forming ability, and antimicrobial resistance of urinary Escherichia coli strains isolated from hospitalized patients.

BACKGROUND/AIM: Escherichia coli is the most frequent cause of urinary tract infections. We investigated the possible associations between the origin of strains, antimicrobial resistance, the presence of urovirulence factors, and biofilm-forming ability. MATERIALS AND METHODS: Antibiotic susceptibility of E. coli strains was tested by disk diffusion method. Hemagglutination assays were performed for phenotypic characterization of the cell surface. Multiplex PCR was used for detection of virulence genes and for determination of phylogenetic relationships. RESULTS: The resistance to ampicillin (55.5%) and tetracycline (39.3%) was significantly more frequent than to other antimicrobial agents. The fim gene was present in 92.5% of strains. The sfa and pap genes were found in 53.8% and 38.7% of strains, respectively. The pap gene was significantly less frequently detected in strains from dialysis patients. The hly gene was present in 18.5% of strains. The aer gene was detected in 52.6% and cnf in 12.1%, while afa was detected in 4.6% of strains. Most strains belonged to the B2 and D phylogenetic groups. The aer gene was significantly associated with strains producing strong biofilms. CONCLUSION: The E. coli strains causing cystitis in hospitalized patients differed in terms of resistance to antibiotics, virulence genes, and potential for biofilm formation.

Antibiofilm activity of trans-cinnamaldehyde, p-coumaric, and ferulic acids on uropathogenic Escherichia coli.

BACKGROUND/AIM: Biofilm on urinary catheters results in persistent infections that are resistant to antibiotics. In this study, phytochemicals were assessed as alternative antimicrobials in preventing and inactivating E. coli biofilm on urinary catheters. MATERIALS AND METHODS: Biofilm prevention was tested using catheter fragments inoculated with E. coli and treated with trans- cinnamaldehyde, p-coumaric, and ferulic acids (0%, 0.1%, 0.25%, and 0.5%) for 0, 1, 3, and 5 days. Inactivation of E. coli biofilm with the same agents at concentrations of 0%, 1%, 1.25%, or 1.5% used for 0, 1, 3, or 5 days was also evaluated. RESULTS: All used concentrations of trans-cinnamaldehyde prevented and effectively inactivated E. coli biofilm formed on urinary catheter fragments. p-Coumaric (0.25% and 0.5%) and ferulic acids (0.5%) had preventive action on E. coli biofilm formation in urinary catheter fragments. The number of uropathogenic E. coli cells in biofilm formed in the lumen of a urinary catheter was significantly reduced in the presence of p-coumaric and ferulic acids, but complete inactivation of the biofilm formed was not observed, as opposed to the use of trans-cinnamaldehyde. CONCLUSION: The obtained results indicate that phytochemicals maybe an important source of antibiofilm agents that have preventive action on E. coli biofilm formation on urinary catheters.