The Prevalence of Alert Pathogens and Microbial Resistance Mechanisms: A Three-Year Retrospective Study in a General Hospital in Poland.

The development of antibiotic resistance mechanisms hinders the treatment process. So far, there is limited data on the problem of bacterial resistance in hospitals in Central and Eastern Europe. Therefore, this study aimed to assess the prevalence of resistance mechanisms and alert pathogens based on reports regarding cultures of samples collected from general hospital patients in Poland in the period 2019-2021. This study examined the prevalence of resistance mechanisms and alert pathogens and the structure of microorganisms, including the type of diagnostic material in the hospital department. The frequency of occurrence and the trends were analysed based on Cochran's Q-test, relative change and the average annual rate of change (AARC). Of all 14,471 cultures, 3875 were positive for bacteria, and 737 were characterised by resistance mechanisms (19.0%). Alert pathogens were identified in 983 cases (24.6%), including pathogens isolated from blood samples. The most commonlyisolated bacteria were Escherichia coli (>20% of positive cultures), Enterococcus faecalis (7%), and Klebsiella pneumoniae (6%) increasing over time; Staphylococcus aureus (13%) was also found, but its proportion was decreasing over time. Extended-spectrum ß-lactamase (ESBL) was the most frequent resistance mechanism in Internal Medicine (IM) (p < 0.001) and the Intensive Care Unit (ICU) (p < 0.01), as well as in ICU-COVID; this increased over the study period (AARC ↑34.9%). Methicillin-resistant Staphylococcus aureus (MRSA) (AARC ↓50.82%) and AmpC beta-lactamase (AARC ↓24.77%) prevalence fell over time. Also, the number of alert pathogens was dominant in the IM (p < 0.01) and ICU (p < 0.001). The most common alert pathogen was ESBL-positive E. coli. Gram-negative rods constitute a significant epidemiological problem in hospitals, especially the growing trend of ESBL in IM and ICU, which calls for increased control of sanitary procedures.

The metabolism of human soluble amyloid precursor protein isoforms is quantifiable by a stable isotope labeling-tandem mass spectrometry method.

Evidence suggests that ß-secretase (BACE1), which cleaves Amyloid Precursor Protein (APP) to form sAPPß and amyloid-ß, is elevated in Alzheimer's disease (AD) brains and biofluids and, thus, BACE1 is a therapeutic target for this devastating disease. The direct product of BACE1 cleavage of APP, sAPPß, serves as a surrogate marker of BACE1 activity in the central nervous system. This biomarker could be utilized to better understand normal APP processing, aberrant processing in the disease setting, and modulations to processing during therapeutic intervention. In this paper, we present a method for measuring the metabolism of sAPPß and another APP proteolytic product, sAPPα, in vivo in humans using stable isotope labeling kinetics, paired with immunoprecipitation and liquid chromatography/tandem mass spectrometry. The method presented herein is robust, reproducible, and precise, and allows for the study of these analytes by taking into account their full dynamic potential as opposed to the traditional methods of absolute concentration quantitation that only provide a static view of a dynamic system. A study of in vivo cerebrospinal fluid sAPPß and sAPPα kinetics using these methods could reveal novel insights into pathophysiological mechanisms of AD, such as increased BACE1 processing of APP.

Blood Culture Contamination: A Single General Hospital Experience of 2-Year Retrospective Study.

In the event of blood culture contamination (BCC), blood culture (BC) needs to be repeated. This may delay appropriate treatment, prolong hospitalization and, consequently, increase its costs. The aim of the study was to assess the frequency of BCC and associated factors in a general hospital in Poland based on reports of BC in samples submitted for laboratory testing in 2019−2020. BCC is recognized when bacteria (especially those belonging to natural human microbiota) are isolated from a single sample and no clinical signs indicated infection. True positive BC is confirmed by the growth of bacteria in more than one set of blood samples with the corresponding clinical signs present. The structure of BC sets, microorganisms, and laboratory costs of BCC were analyzed. Out of 2274 total BC cases, 11.5% were true positive BC and 9.5% were BCC. Of all the BCC identified in the entire hospital, 72% was from Internal Medicine (IM) and Intensive Care Unit (ICU) combined. When single sets for BC were used in IM in 2020, the use increased to 85% compared with 2019 (p < 0.05). The predominant isolates were coagulase-negative staphylococci (84%). The estimated extra laboratory costs of BCC exceeded EUR 268,000. The BCC was a more serious problem than expected, including non-recommended using of single BC sets. Compliance with the BC collection procedure should be increased in order to reduce BCC and thus extra hospital costs.

Cytokine and LL-37 gene expression levels in Bartonella spp. seropositive and seronegative patients of a rheumatology clinic.

PURPOSE: The variation in the immune response to Bartonella spp. infection in humans remains unclear. The present study compares the expression of selected interleukins, cytokines and cathelicidin (LL-37) in rheumatology clinic patients suffering from musculoskeletal symptoms with healthy blood donors. The patients had previously been tested for the presence of Bartonella henselae antibodies. METHODS: Gene expression of LL-37, interleukin (IL)-2, IL-4, IL-6, IL-12, interferon-(IFN)-γ, and tumor necrosis factor (TNF-α)-α was determined in blood samples using quantitative Polymerase Chain Reaction (qPCR). Statistical analysis was prepared with STATISTICA. RESULTS: Statistically significant differences in the mRNA levels of the tested cytokines (IFN-γ, TNF-α, IL-2, IL-4, IL-6, IL-12; p<0.0001) were observed between the healthy controls and patients; however, no difference was observed for LL37 mRNA (p â€‹= â€‹0.1974). No significant differences in mRNA expression were observed between IgG in anti-Bartonella seropositive and seronegative individuals (p>0.05). The only significant differences between the Bartonella spp. DNA positive and negative patients, indicated by PCR, were observed for TNF-α and IL-12 mRNA (p â€‹= â€‹0.0045 and p â€‹= â€‹0.0255, respectively). CONCLUSION: A broadly similar immune response to the tested cytokines was observed among the participants irrespective of anti-Bartonella spp. IgG seropositivity. However, the Bartonella DNA-positive participants demonstrated significantly lower expression of IL-12 and TNF-α mRNA; this may indicate that these bacteria have a suppressive influence on the immune system.

The seroprevalence of Bartonella spp. in the blood of patients with musculoskeletal complaints and blood donors, Poland: a pilot study.

BACKGROUND: Bartonella spp. can cause a variety of diseases, such as lymphadenopathies, cat scratch disease, and trench fever, but can also give rise to many non-specific symptoms. No data exists regarding the prevalence of Bartonella spp. in patients with musculoskeletal complaints, nor among blood donors in Poland. METHODS: The presence of anti-Bartonella IgM and IgG in the serum of blood donors (n = 65) (Lodz, Poland) and in the patients of the Department of Rheumatology Clinic (n = 40) suffering from musculoskeletal symptoms was tested by immunofluorescence. Blood samples were cultured on enriched media. Epidemiological questionnaires were used to identify key potential risk factors, such as sex, age, contact with companion animals, and bites from insects or animals. RESULTS: Altogether, 27 of the 105 tested subjects were seropositive for Bartonella henselae IgG (23%) and three for Bartonella quintana IgG (2.85%); IgMs against B. henselae were found in three individuals (2.85%), and IgMs against B. quintana were found in one (1.54%). No statistically significant difference was found between the prevalence of B. henselae in the blood of donors or patients and the presence of unexplained musculoskeletal complaints (23% vs 30%). Individuals who had kept or been scratched by cats were not more likely to be B. henselae seropositive (p > 0.01). Tick bites were more commonly reported in patients, but insignificantly (p > 0.01). CONCLUSION: This is the first report of a high seroprevalence of anti-Bartonella IgG in patients with musculoskeletal symptoms and in blood donors in Poland. The obtained results indicate that such seroprevalence may have a possible significance in the development of musculoskeletal symptoms, although it should be confirmed on a larger group of patients. Asymptomatic bacteremia might occur and pose a threat to recipients of blood from infected donors. Hence, there is a need for more detailed research, including molecular biology methods, to clarify the potential risk of Bartonella spp. being spread to immunocompromised individuals. KEY POINTS: • This is the first study presenting high seroprevalence of Bartonella spp. in Poland. • IgG and IgM antibodies against B. quintana were found in blood samples of blood donors.

The ability of selected plant essential oils to enhance the action of recommended antibiotics against pathogenic wound bacteria.

The aim of this work was to characterize the ability of essential oils to support antibiotics against pathogenic bacteria in wounds. Gram-positive and Gram-negative bacteria obtained from wound infections were identified according to standard microbiological methods. Essential oils were analysed by GC-FID-MS. The susceptibility of bacteria to antibiotics, essential oils and their combination was assessed using the disc-diffusion method. The Minimal Inhibitory Concentration and Minimum Bactericidal Concentration of the essential oils were established by the micro-dilution broth method. Although cinnamon, clove, thyme and lavender essential oils were found to have the greatest antibacterial activity when used alone, the greatest additive and synergistic effects against pathogenic wound bacteria in combination with recommended antibiotics were demonstrated by basil, clary sage and rosemary oils.

The Sensitivity of Endodontic Enterococcus spp. Strains to Geranium Essential Oil.

Enterococci are able to survive endodontic procedures and contribute to the failure of endodontic therapy. Thus, it is essential to identify novel ways of eradicating them from infected root canals. One such approach may be the use of antimicrobials such as plant essential oils. Enterococcal strains were isolated from endodontically treated teeth by standard microbiological methods. Susceptibility to antibiotics was evaluated by the disc-diffusion method. The minimal inhibitory concentration (MIC) of geranium essential oil was investigated by microdilution in 96-well microplates in Mueller Hinton Broth II. Biofilm eradication concentrations were checked in dentin tests. Geranium essential oil inhibited enterococcal strains at concentrations ranging from 1.8-4.5 mg/mL. No correlation was shown between resistance to antibiotics and the MICs of the test antimicrobials. The MICs of the test oil were lower than those found to show cytotoxic effects on the HMEC-1 cell line. Geranium essential oil eradicated enterococcal biofilm at concentrations of 150 mg/mL. Geranium essential oil inhibits the growth of endodontic enterococcal species at lower concentrations than those required to reach IC50 against the HMEC-1 cell line, and is effective against bacteria protected in biofilm at higher concentrations. In addition, bacteria do not develop resistance to essential oils. Hence, geranium essential oil represents a possible alternative to other antimicrobials during endodontic procedures.

The activity of silver nanoparticles (Axonnite) on clinical and environmental strains of Acinetobacter spp.

Acinetobacter baumannii isolates are responsible for a high number of wound infections. The reason of this study was to evaluate the activity of silver nanoparticles obtained by microexplosion against wide range of Acinetobacter spp. Susceptibility to silver nanoparticles was tested by microdilution method, susceptibility to antibiotics was evaluated by the disc-diffusion method. All strains of Acinetobacter spp. were sensitive to AgNPs at low concentrations. The values of the MIC for strains of Acinetobacter spp. were 0.39 and 0.78µg/mL. In general, strains inhibited by 0.78µg/mL of AgNPs were more resistant to antibiotics than Acinetobacter strains for which MIC=0.39µg/mL (p=0.023). The AgNPs in Axonnite seems to be a good alternative for other antimicrobials to treat wound infections caused by multidrug resistant Acinetobacter spp. strains because of its high activity.

The biological activities of cinnamon, geranium and lavender essential oils.

Acinetobacter sp. represent an important cause of nosocomial infections. Their resistance to some antibiotics, their ability to survive on inanimate surfaces in the hospital environment and their ability to produce biofilms contributes to their virulence. The aim of the study was to determine the antibacterial properties of cinnamon, lavender and geranium essential oils against bacteria of the genus Acinetobacter isolated from several clinical materials and from the hospital environment. A comprehensive evaluation of the susceptibility of Acinetobacter sp. clinical strains to recommended antibiotics was performed. The constituents of cinnamon, lavender and geranium essential oils were identified by GC-FID-MS analysis, and their Minimal Inhibitory Concentrations (MICs) against tested clinical strains were determined by the micro-dilution broth method. In addition, the effects of essential oils on the viability of human microvascular endothelial cells (HMEC-1) and glioblastoma cell line (T98G) were evaluated. Cinnamon bark oil was the most active against clinical and environmental strains of Acinetobacter baumannii with MIC values ranging from 0.5 to 2.5 µL/mL. The MIC values for geranium oil were between 7.5 and 9.5 µL/mL, and between 10.5 and 13.0 µL/mL for lavender oil. These essential oils can be best employed in the fight against infections caused by bacteria from Acinetobacter genus as components of formulations for hygiene and disinfection of hospital environment.

[The antibacterial activity of cinnamon oil on the selected gram-positive and gram-negative bacteria]. / Przeciwbakteryjne dzialanie olejku cynamonowego na wybrane bakterie gram-dodatnie i gram-ujemne.

INTRODUCTION: The aim of our study was to determine the antibacterial activity of cinnamon bark oil against Gram-positive and Gram-negative isolates belonging to Staphylococcus, Enterococcus, Enterobacter and Acinetobacter genera come from different clinical specimens. METHODS: The microdilution method was used to determine the minimum inhibitory concentration--MIC for cinnamon bark oil. Susceptibility testing to antibiotics was carried out using disc-diffusion method. RESULTS: Our investigations showed that the tested cinnamon bark oil was inhibiting activity against all isolates. The MIC for Gram-positive bacteria were between 01.25 and 1.5 µl/ml and for Gram-negative between 1.0 and 1.75 µl/ml. The tested bacteria come from Staphylococcus, Enterococcus, Enterobacter and Acinetobacter genera were susceptible to essential oil obtained from Cinnamomum zeylanicum Ness in low concentrations, despite the fact that the bacteria characterized the high resistance to recommended antibiotics. No correlation was found between the antibiotic resistance of the bacterial strains and their sensitivity to essential oil. CONCLUSIONS: The cinnamon bark oil due to the strong activity can be used as alternative antibacterial agents in cosmetics, toiletries and disinfectants applied in hospital environment.

The potential of use basil and rosemary essential oils as effective antibacterial agents.

The considerable therapeutical problems of persistent infections caused by multidrug-resistant bacterial strains constitute a continuing need to find effective antimicrobial agents. The aim of this study was to demonstrate the activities of basil (Ocimum basilicum L.) and rosemary (Rosmarinus officinalis L.) essential oils against multidrug- resistant clinical strains of Escherichia coli. A detailed analysis was performed of the resistance of the drug to the strains and their sensitivity to the tested oils. The antibacterial activity of the oils was tested against standard strain Escherichia coli ATCC 25922 as well as 60 other clinical strains of Escherichia coli. The clinical strains were obtained from patients with infections of the respiratory tract, abdominal cavity, urinary tract, skin and from hospital equipment. The inhibition of microbial growth by both essential oils, presented as MIC values, were determined by agar dilution. Susceptibility testing to antibiotics was carried out using disc diffusion. The results showed that both tested essential oils are active against all of the clinical strains from Escherichia coli including extended-spectrum ß-lactamase positive bacteria, but basil oil possesses a higher ability to inhibit growth. These studies may hasten the application of essential oils in the treatment and prevention of emergent resistant strains in nosocomial infections.

The activity of silver nanoparticles (axonnite) on clinical and environmental strains of Enterococcus spp.

AIMS: The spread of bacterial antibiotic resistance among clinical strains is a growing problem nowadays. Resistance in Enterococcus spp. strains has merited special concern of late, as they have become significant nosocomial pathogens. Hence, the use of compounds such as silver nanoparticles (AgNPs), displaying various mechanisms of action, is a growing new approach against virulent, drug-resistant infections. Therefore, the activity of AgNPs obtained by a physical method (microexplosion method) was tested against 30 clinical and environmental Enterococcus spp. strains presenting diverse virulence and resistance patterns. RESULTS: The minimal inhibitory concentration for all the species ranged from 0.39 to 3.125 µg/ml. No statistical differences (p=0.26) were found between resistance to AgNPs and resistance to antibiotics, suggesting high activity of AgNPs even against multidrug-resistant strains. CONCLUSIONS: AgNPs obtained by this method seem to be a promising alternative to chemotherapeutics in the treatment or prevention of enterococcal infections.

Frequency of ace, epa and elrA Genes in Clinical and Environmental Strains of Enterococcus faecalis.

Surface proteins play an important role in the pathogenesis of enterococcal infections. Some of them are candidates for a vaccine, e.g., the frequency of endocarditis in rats vaccinated with Ace protein was 75 % as 12 opposed to 100 % in those who weren't. However, there are other components of enterococcal cells, such as Epa antigens or internalin-like proteins, which may be used in the prophylaxis of infections caused by them. However, also other virulence factors and resistance to antibiotics are important during enterococcal infection. Therefore, the relevance of ace, epa, elrA, other virulence genes, as well as resistance to antibiotics was investigated. 161 Enterococcus faecalis strains isolated from teaching hospitals in Lodz, cultured according to standard microbiological methods, were investigated for the presence of genes encoding surface proteins by PCR. Results were analyzed with χ(2) test. The elrA gene was found in all clinical and environmental strains, the ace gene was also widespread among E. faecalis (96.9 %). Both tested epa genes were found in the majority of isolates (83.25 %). There was correlation between the presence of esp and ace genes (p = 0.046) as well as between epa and agg genes (p = 0.0094; χ(2) test). The presence of the genes encoding surface proteins investigated in our study in the great majority of isolates implies that they would appear to be required during E. faecalis infection. Therefore, they could be excellent targets in therapy of enterococcal infections or, as some studies show, candidates for vaccines.

The antimicrobial activity of thyme essential oil against multidrug resistant clinical bacterial strains.

AIM: The aim of this work was to investigate the antimicrobial activity of thyme essential oil against clinical multidrug resistant strains of Staphylococcus, Enterococcus, Escherichia, and Pseudomonas genus. MATERIALS: The antibacterial activity of oil was tested against standard strains of bacteria and 120 clinical strains isolated from patients with infections of the oral cavity, abdominal cavity, respiratory and genitourinary tracts, skin, and from the hospital environment. METHODS: Agar diffusion was used to determine the microbial growth inhibition of bacterial growth at various concentrations of oil from Thymus vulgaris. Susceptibility testing to antibiotics was carried out using disk diffusion. RESULTS: Thyme essential oil strongly inhibited the growth of the clinical strains of bacteria tested. CONCLUSIONS: The use of phytopharmaceuticals based on an investigated essential oil from thyme in the prevention and treatment of various human infections may be reasonable.

Antibacterial activity of thyme and lavender essential oils.

Strong antiseptic activity of essential oils has been known for a long time. The antibacterial activity of oils was tested against clinical bacterial strains of Staphylococcus, Enterococcus, Escherichia and Pseudomonas genera. The agar diffusion method was used for microbial growth inhibition at various concentrations of the oils from T. vulgaris and L. angustifolia. Susceptibility testing to antibiotics and chemotherapeutics was carried out using disc-diffusion method. 120 strains of bacteria isolated from patients with infections of oral cavity, respiratory, genitourinary tracts and from hospital environment were investigated. The results of experiments showed that the oil from T. vulgaris exhibited extremely strong activity against all of the clinical strains. Thyme oil demonstrated a good efficacy against antibiotics resistant strains of the tested bacteria. Lavender oil has been less activity against clinical strains of Staphylococcus, Enterococcus and Escherichia genus. The worst results have been observed against all strains of Pseudomonas aeruginosa.

[Occurrence of virulence genes among Enterococcus faecalis strains isolated from patients and hospital environment]. / Wystepowanie genów zjadliwosci wsród szczepów Enterococcus faecalis izolowanych od pacjentów i ze srodowiska szpitalnego.

The aim of this study was to evaluate occurrence of virulence genes among Enterococcus faecalis strains isolated from two hospitals in Lódz, during 2005-2006. The second goal was to determine possible relationship between presence of those genes, resistance to ampicillin and sources of isolation. Enterococcal strains were identified to the species by PCR with ddl primers. All 161 isolates were tested for the presence of aggregation substance gene (agg), cytolisine genes (cyl-L, cyl-S), esp protein gene, gelatinase gene (gelE), serine protease gene (sprE). Susceptibility to ampicillin was tested by microdillution method. Both cyl-L and cyl-S genes were found in 52,2% of strains, agg gene was present in 62,73% isolates, esp gene--in 71.2%. Most frequently found genes were gelE (85.1%) and sprE (82.6%). The presence of esp gene in isolates resistant to ampicillin was statistically higher than in susceptible strains, what might suggest appearance of epidemic strains. Besides, strains possessing both, cyl-L/S and esp genes, were found to be statistically more often isolated strains than those possessing only single genes.

[Susceptibility to antimicrobial agents and genotypic relatedness of enterococcal strains isolated from patients and hospital environment]. / Lekowrazliwosc i pokrewienstwo szczepów Enterococcus sp. izolowanych od pacjentów i ze srodowiska szpitalnego.

The aim of this study was to evaluate antibiotic susceptibility of Enterococcus sp. strains isolated from two hospitals in lódz, during 2005-2006. The second goal was to determine possible transmission of these strains within hospital wards by using melting profile PCR. Enterococcal strains were identified to species according standard microbiological methods. There was isolated 159 strains of E. faecalis, 51 strains of E. faecium and two E. avium, 1 E. durans. Susceptibility to antimicrobial agents was tested by disc diffusion method. None of these strains was resistant to vancomycin, teicoplanin or linezolid. There was high percentage of strains resistant to aminoglicosides, 22% of E. faecalis strains, and 54.9% of E. faecium strains, respectively. Additionally it was shown that 11.7% of E. faecium is resistant to chinuprisin-dalfopristin. The strains with similar pattern of resistance to antibiotics and fenotypic characteristics were genotyped by mpPCR. This technique was useful to confirm relatedness of bacterial strains suspected of being spread within hospital wards.