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Disinfectants and antiseptics lead in reducing the number of microorganisms, including pathogenic ones, thus limiting the number of infections. In the veterinary field, disinfection prevents the transfer of pathogenic microorganisms from animals to humans and vice versa , as well as among animals. Several assays of disinfectant antimicrobial activity testing, often not standardized, without appropriate controls, and not validated, have been used and published. To unify these methods, nine European Standards (ENs) for the veterinary area have been prepared. These tests make it possible to examine whether a given disinfectant has bactericidal, fungicidal, or virucidal activity by the standard. This publication discusses ENs regarding the assessment of the above-mentioned antimicrobial activity of disinfectants used in veterinary medicine. Recent research on this topic has also been cited. According to ENs, tests are carried out using the suspension method or carriers in clean and dirty conditions. The decontamination of high-risk animal and zoonotic pathogens is also discussed. Selected publications on cattle, pig, poultry, and aquaculture farm disinfection are presented. Only valid methods of the described studies with appropriate statistical analysis can prove adequate antimicrobial activity. So far, the role of international standards in investigating the antimicrobial activity of disinfectants and antiseptics to reduce infections has been underestimated. This publication highlights gaps and irregularities in conducted research and aims to inform about existing EN standards dedicated to testing the biocidal activity of disinfectants and antiseptics intended for use in the veterinary area., (© 2024 Stefan Tyski et al., published by Sciendo.)

Non-steroidal anti-inflammatory drugs (NSAIDs) commonly used in clinical practice may cause gastrointestinal injuries and influence the gut microbiota. This study investigated the effects of various NSAIDs and some analgesics on the viability of Lactobacillaceae strains (including probiotic strains) in vitro . It was found that diclofenac, ibuprofen, ketoprofen, dexketoprofen, flurbiprofen, and acetylsalicylic acid inhibited the growth of lactobacilli at a concentration of 0.05-3.2 mg/ml. These MICs of NSAIDs are well above therapeutic plasma concentrations achieved in humans, indicating that the tested drugs should not inhibit the growth of lactobacilli in the human digestive tract., (© 2023 Hanna Kruszewska et al., published by Sciendo.)

Lactic acid bacteria are used in various types of probiotic products. Due to the constantly growing probiotics market, new strains with pro-health properties are sought. The present study compared 39 strains of Lactobacillus, Lacticaseibacillus , and Lactiplantibacillus , isolated from probiotic products and healthy people. The current research aimed to search for new, potentially probiotic strains. For this purpose the relationship between Lactobacillaceae strains was carried out; moreover, the basic properties of probiotic microorganisms, such as survival at low pH and bile salt environment, antibiotic susceptibility, aggregation and antagonism were estimated. The properties of these isolates were also compared with the properties of probiotic strains from the ATCC collection. In comparing the genetic relationship (PFGE method) between the tested isolates, it was observed that some of them show a high degree of similarity. All tested strains tolerated an environment with a pH value of 3.0, and the addition of 0.3% bile salt; showed auto-aggregation properties and displayed antagonism against pathogenic microorganisms. In the present study, the bacteria were susceptible to tetracycline, chloramphenicol and ampicillin; the resistance to vancomycin depended on the bacteria type. All the properties were strain-depended. Most of the tested strains had properties comparable to the reference strains. Three L. acidophilus strains isolated from cervical swabs seem to be promising candidates for probiotic strains., (© 2022 Anna Zawistowska-Rojek et al., published by Sciendo.)

Sixty-five colistin-resistant Enterobacterales isolates recovered from different clinical specimens were analyzed. The strains were collected in 12 hospitals all over Poland within a period of nine months. Strains were analyzed for eight genes from the mcr family. The presence of mcr -1 gene was detected in three Escherichia coli strains. The 45/65 isolates were identified as ESBL producers. CTX-M-1-like enzymes were the most common ESBLs (n = 40). One E. coli and seven Klebsiella pneumoniae strains produced carbapenemases, with the NDM being produced by five isolates. Among all the strains tested, four and five were resistant to new drugs meropenem/vaborbactam and ceftazidime/avibactam, respectively., Competing Interests: Conflict of interest The authors do not report any financial or personal connections with other persons or organizations, which might negatively affect the contents of this publication and/or claim authorship rights to this publication., (© 2021 Elżbieta M. Stefaniuk et al.)

Colistin is a member of cationic polypeptide antibiotics known as polymyxins. It is widely used in animal husbandry, plant cultivation, animal and human medicine and is increasingly used as one of the last available treatment options for patients with severe infections with carbapenem-resistant Gram-negative bacilli. Due to the increased use of colistin in treating infections caused by multidrug-resistant (MDR) bacteria, the resistance to this antibiotic ought to be monitored. Bacterial resistance to colistin may be encoded on transposable genetic elements (e.g. plasmids with the mcr genes). Thus far, nine variants of the mcr gene, mcr-1 - mcr-9 , have been identified. Chromosomal resistance to colistin is associated with the modification of lipopolysaccharide (LPS). Various methods, from classical microbiology to molecular biology methods, are used to detect the colistin-resistant bacterial strains and to identify resistance mechanisms. The broth dilution method is recommended for susceptibility testing of bacteria to colistin., Colistin is a member of cationic polypeptide antibiotics known as polymyxins. It is widely used in animal husbandry, plant cultivation, animal and human medicine and is increasingly used as one of the last available treatment options for patients with severe infections with carbapenem-resistant Gram-negative bacilli. Due to the increased use of colistin in treating infections caused by multidrug-resistant (MDR) bacteria, the resistance to this antibiotic ought to be monitored. Bacterial resistance to colistin may be encoded on transposable genetic elements (e.g. plasmids with the mcr genes). Thus far, nine variants of the mcr gene, mcr-1 – mcr-9 , have been identified. Chromosomal resistance to colistin is associated with the modification of lipopolysaccharide (LPS). Various methods, from classical microbiology to molecular biology methods, are used to detect the colistin-resistant bacterial strains and to identify resistance mechanisms. The broth dilution method is recommended for susceptibility testing of bacteria to colistin.

Probiotic bacteria have been used as a health-promoting factor for a very long time. Nowadays, products containing probiotic bacteria are becoming more and more popular on the market. The term probiotics refers to the products belonging to the following groups: probiotic drugs (medicinal products - live biotherapeutic products for human use), medical devices, probiotic foods (e.g. foods, food ingredients, dietary supplements or food for special medical purposes), directly fed microorganisms (for animal use) and designer probiotics (genetically modified probiotics). Safety assessment of bacterial strains used as probiotics should be carefully studied. Even though probiotic bacteria have the generally recognized as safe (GRAS status), there are several reports about side effects triggered by the presence of these organisms. Microorganisms used as probiotics may cause systemic infections, stimulate the immune system, disturb metabolism and participate in horizontal gene transfer., (© 2018 Anna Zawistowska-Rojek and Stefan Tyski.)

The aim of this study was to perform the microbiological analysis of quality of 25 probiotic products, available on the Polish market. Analysis of bacterial viability in probiotic products showed that not all of these preparations possess a suitable number of bacteria. Moreover, some of the tested probiotic products contained bacterial strains other than those declared by the manufacturer. All tested strains recovered from probiotic products were found to be resistant to metronidazole and susceptible to nitrofurantoin. The susceptibility to other antibiotics was strain specific. Probiotic products should be subject to regular and thorough inspection by appropriate institutions.

Staphylococcus epidermidis, a coagulase-negative Staphylococcus, is the most important pathogen responsible for chronic nosocomial infections. These bacteria produce extracellular slime and form biofilms on various biotic and abiotic surfaces. Bacterial biofilms are very resistant to standard antimicrobial therapy and difficult to eradicate, so it is important to search for new more effective anti-biofilm agents, for example in the group of natural substances. The aim of the study was to examine the activity of two ionophores-salinomycin and monensin against clinical S. epidermidis strains, using MIC/MBC method and biofilm formation inhibition assay. Bacterial strains were tested also for slime production using Congo Red Agar. Both tested ionophore antibiotics showed the highest activity against planktonic bacteria of clinical as well as standard S. epidermidis strains and effectively inhibited the formation of bacterial biofilm.

Quaternary ammonium compounds are broad-spectrum bacteriocides widely used as antiseptics, disinfection and preservation agents. The aim of this study was to examine the activity of two quaternary ammonium salts, cetylpyridinum bromide and a newly synthesized quaternary bis ammonium salt, against S. epidermidis biofilm. The average values of killing efficiency for cetylpyridinum bromide ranged from 26.6% to 64.1% for all tested concentrations (0.125 to 8.0 microg x mL(-1)) and for quaternary bis ammonium salt the percentage of killing efficiency ranged from 59.7% to 88.4% for tested concentrations (from 2.0 to 128.0 microg x mL(-1)). Both tested compounds significantly affect staphylococcal biofilms, but any of used concentrations caused a total eradication of bacterial biofilm.

Introduction of a new antimicrobial agent as a drug--for treatment of infections or as a disinfectant and antiseptic, may result in the occurrence of resistance mechanisms against this agent among microorganisms. Two disinfectants of different composition--Incidin Plus for surface disinfection and Sekusept Plus for medical devices disinfection, both containing glucoprotamin as the active substance, were investigated in this study in order to analyze their antimicrobial activity. Standard bacterial and fungal strains recommended by European Standards, established by European Standardization Committee for testing bactericidal and fungicidal activity of chemical disinfectants were used in the study. Furthermore, 60 clinical bacterial strains with different susceptibility to antibiotics and chemotherapeutics, mostly multiresistant, isolated from different specimens from hospitalized patients were analyzed. In addition, 184 fungal clinical strains isolated from hospitalized patients and outpatients were also included in this study. Antimicrobial activity was evaluated according to EN 1040:2005 --using bacterial strains and according to EN 1275:2005--using fungal strains. Glucoprotamin proved to be a very effective and rapidly acting bactericidal and fungicidal agent. Low concentration of glucoprotamin--0.5% showed to be very effective (1 min) against clinical bacterial isolates. Incidin Plus was also very effective (5 min) against clinical fungal isolates.

Antibacterial and antifungal activity of 2,4-dihydro- [1,2,4]triazol-3-one derivatives were examined by the disc-diffusion method (growth inhibition zone diameter in agar medium). The MIC's for the most active agents were determined. Of all the tested compounds, aminomethyl derivatives of 2,4-dihydro-[1,2,4]triazol-3-one exhibit activity against the majority of microorganisms studied.