Salmonella enterica serotypes isolated for the first time in laying hens, and their susceptibility to antibiotics.

In this study, a total of 323 drag swab samples were taken from laying hen fresh feces from 3 different provinces (Kirklareli, Edirne, and Tekirdag), which are located in the European part of Türkiye. According to the ISO 6579: 2002 method, 17.3% of the samples were found positive for Salmonella. Obtained 56 Salmonella isolates were serotyped by slide agglutination using antisera according to Kauffmann White Le Minor Scheme. Sixteen serotypes of Salmonella were identified as S. Typhimurium (28.6%), S. Kentucky (17.9%), S. Abony (16.1%), S. Infantis (8.9%), S. Enteritidis (5.4%), S. Anatum (3.6%), S. Saintpaul (3.6%), S. Szentes (1.8%), S. Dibra (1.8%), S. Fallowfield (1.8%), S. Kimuenza (1.8%), S. Escanaba (1.8%), S. Nagoya (1.8%), S. Mbandaka (1.8%), S. Agona (1.8%), and Salmonella II 17: e, n, x, z15: 1,6 (1.8%). Isolations of S. Kimuenza, S. Escanaba, and S. Nagoya from laying hens are reported for the first time in Türkiye. The isolations of S. Dibra, S. Fallowfield, S. Szentes, and Salmonella II 17: e, n, x, z15: 1,6 from laying hens are the first report in the world. A total of 56 Salmonella isolates were tested for susceptibility to amoxicillin-clavulanic acid, cefepime, azithromycin, cefoxitin, and trimethoprim/sulfamethoxazole by the disk diffusion method. While 10% of S. Kentucky isolates were resistant to ofloxacin, and S. Kimuenza was only resistant to chloramphenicol.

Synthesis, antimicrobial activity, density functional modelling and molecular docking with COVID-19 main protease studies of benzoxazole derivative: 2-(p-chloro-benzyl)-5-[3-(4-ethly-1-piperazynl) propionamido]-benzoxazole.

This study contains synthesis, antimicrobial activity, density functional modelling and molecular docking studies of benzoxazole derivative: 2-(p-chloro-benzyl)-5-[3-(4-ethly-1-piperazynl) propionamido]-benzoxazole. The synthetic procedure of investigated compound is given in detail. The newly synthesized benzoxazole compound and standard drugs were evaluated for their antimicrobial activity against some Gram-positive, Gram-negative bacteria and fungus C. albicans and their drug-resistant isolates. The benzoxazole compound has been characterized by using 1H-NMR, IR and MASS spectrometry and elemental analysis techniques. The molecular structure of the compound in the ground state has been modelling using density functional theory (DFT) with B3LYP/6-311++g(d,p) level. The molecular docking of 2-(p-chloro-benzyl)-5-[3-(4-ethly-1-piperazynl) propionamido]-benzoxazole with COVID-19 main protease has been also performed by using optimized geometry and the experimentally determined dimensional structure of the main protease (M-pro) of COVID-19.

Antibacterial, antifungal and antimycobacterial activities of some pyrazoline, hydrazone and chalcone derivatives.

Twenty-seven previously reported chalcones and their pyrazoline and hydrazone derivatives as well as two further chalcones have been screened for their antimicrobial, antifungal and antimycobacterial activities against standard microbial strains and drug resistant isolates. The minimum inhibitory concentration (MIC) value of each compound was determined by a two-fold serial microdilution technique. The compounds were found to possess a broad spectrum of antimicrobial activities with MIC values of 8-128 µg/mL. One compound [(E)-1-(4-hydroxyphenyl)-3-p-tolylprop-2-en-1-one] had equal activity with gentamycin (8 µg/mL) against Enterococcus faecalis. Chalcones were found to be more active than their hydrazone and 2-pyrazoline derivatives against Staphylococcus aureus ATCC 29213 and E. faecalis ATCC 29212.

Antimicrobial and antibiofilm effects of selected food preservatives against Salmonella spp. isolated from chicken samples.

Salmonella spp. are widespread foodborne pathogens that contaminate egg and poultry meats. Attachment, colonization, as well as biofilm formation capacity of Salmonella spp. on food and contact surfaces of food may cause continuous contamination. Biofilm may play a crucial role in the survival of salmonellae under unfavorable environmental conditions, such as in animal slaughterhouses and processing plants. This could serve as a reservoir compromising food safety and human health. Addition of antimicrobial preservatives extends shelf lives of food products, but even when products are supplemented with adequate amounts of preservatives, it is not always possible to inhibit the microorganisms in a biofilm community. In this study, our aims were i) to determine the minimum inhibitory concentrations (MIC) and minimum biofilm inhibitory concentrations (MBIC) of selected preservatives against planktonic and biofilm forms of Salmonella spp. isolated from chicken samples and Salmonella Typhimurium SL1344 standard strain, ii) to show the differences in the susceptibility patterns of same strains versus the planktonic and biofilm forms to the same preservative agent, and iii) to determine and compare antimicrobial and antibiofilm effects of selected food preservatives against Salmonella spp. For this purpose, Salmonella Typhimurium SL1344 standard strain and 4 Salmonella spp. strains isolated from chicken samples were used. Investigation of antimicrobial and antibiofilm effects of selected food preservatives against Salmonella spp. was done according to Clinical and Laboratory Standards Institute M100-S18 guidelines and BioTimer assay, respectively. As preservative agents, pure ciprofloxacin, sodium nitrite, potassium sorbate, sodium benzoate, methyl paraben, and propyl paraben were selected. As a result, it was determined that MBIC values are greater than the MIC values of the preservatives. This result verified the resistance seen in a biofilm community to food preservatives and highlighted this subject, not to be ignored in food applications.

Screening of quinolone antibiotic residues in chicken meat and beef sold in the markets of Ankara, Turkey.

This study aimed to find the effects of quinolone antibiotics in chicken and beef used in Ankara, Turkey. Total number of 127 chicken and 104 beef meat samples were collected randomly from local markets for analysis. Extraction and determination of quinolones were made by ELISA procedure. One hundred eighteen of 231 (51.1%) examined chicken meat and beef samples were found to contain quinolone antibiotic residue. Among the chicken meat and beef samples, 58 (45.7%) of chicken meat samples and 60 (57.7%) of beef meat samples were positive for quinolones, respectively. The mean levels (±SE) of quinolones were found to be 30.81 ± 0.45 µg/kg and 6.64 ± 1.11 µg/kg in chicken and beef samples, respectively. This study indicated that some chicken and beef meat sold in Ankara contains residues of quinolone antibiotics.

Synthesis and in vitro biological activity of new 4,6-disubstituted 3(2H)-pyridazinone-acetohydrazide derivatives.

New 3(2H)-pyridazinone derivatives containing a N'-benzyliden-acetohydrazide moiety at position 2 were synthesized. The structures of these newly synthesized compounds were confirmed by IR, 1H NMR, and MS data. These compounds were tested for their antibacterial, antifungal, antimycobacterial, and cytotoxic activities. The compounds 2-[4-(4-chlorophenyl)-6-(morpholin-4-yl)-3-oxo-(2H)-pyridazin-2-yl]-N'-(4-tert-butylbenzyliden)acetohydrazide and 2-[4-(4-chlorophenyl)-6-(morpholin-4-yl)-3-oxo-(2H)-pyridazin-2-yl]-N'-(4-chlorobenzyliden) acetohydrazide exhibited activity against both Gram-positive and Gram-negative bacteria. Most of the compounds were active against E. coli ATCC 35218. The preliminary results of this study revealed that some target compounds exhibited promising antimicrobial activities.

Synthesis, antioxidant and antimicrobial evaluation of simple aromatic esters of ferulic acid.

Aromatic ester derivatives of ferulic acid where the phenolic hydroxyl is free (6a-d) or acetylated (5a-d) were evaluated for their antioxidant and antimicrobial properties. The superoxide radical scavenging capacity of compounds 5d and 6d-e (IC(50) of 0.19, 0.27 and 0.20 mM, respectively) was found to be twice as active as α-tocopherol (IC(50) = 0.51 mM). DPPH radical scavenging capacity was moderate and only found in compounds bearing free phenolic hydroxyl groups (6a-e). With regard to antimicrobial properties, compounds 6b and 6c displayed significant activity against Enterococcus faecalis (MICs = 16 µg/mL) and vancomycin-resistant E. faecalis (MIC for 6b, 32 and for 6c, 16 µg/mL). Compound 6c also demonstrated prominent activity against planktonic Staphylococcus aureus with a MIC value of <8 µg/mL and it inhibited bacterial biofilm formation by S. aureus with a MBEC value of <8 µg/mL, which was 64 and 128 times more potent than ofloxacin and vancomycin, respectively.

Candida albicans and Pseudomonas aeruginosa adhesion on soft contact lenses.

BACKGROUND: In this study it was aimed to determine the adherence of Pseudomonas and Candida to contact lens surfaces, and to determine the difference in adherence between five contact lens types. Biofilm-negative control strains were also used to emphasize the difference between biofilm-positive and biofilm-negative strains in adherence. METHODS: Five different soft contact lenses were used to investigate the adherence of Pseudomonas aeruginosa and Candida albicans strains. P. aeruginosa ATCC 27853, P. aeruginosa ATCC 10145, C.albicans ATCC 10231 standard strains and C. albicans clinical isolate were included in the study. Slime formation was investigated by two methods; modified Christensen macrotube method, and a modified microtiter plate test. P. aeruginosa and C. albicans slime formation on soft contact lenses was studied in adherence and separation phases. Pseudomonas and Candida suspensions were serially diluted and inoculated to blood agar and sabouraud dextrose agar surfaces respectively. After overnight incubation, the colonies were counted. Sterile unworn contact lenses were used as negative controls, and bacterial and fungal culture suspensions were used as positive controls. The experiments were conducted in three parallel series. RESULTS: The number of adherent Pseudomonas was as follows from high to low in polymacon, etafilcon A, hilafilcon, ocufilcon and lotrafilcon contact lenses respectively. However, the number of adherent yeast were determined higher in lotrafilcon and ocufilcon contact lenses, followed by hilafilcon, etafilcon A and polymacon contact lenses. Biofilm-negative Pseudomonas ATCC standard strain and Candida clinical isolate were used to confirm that the number of adherent cells were lower than the biofilm-positive ones. CONCLUSIONS: This study demonstrates that in addition to the contact lens properties, the microorganisms themselves and their interactions with the lens material also play an important role in adherence.