This study aimed to investigate the presence of Salmonella spp. in chicken doner samples, both ready for consumption and sold in packages in a modified atmosphere, using classical culture technique and the MALDI-TOF method by determining the antibiotic resistance profile structure through the disc diffusion method by determining the serotypes of the isolates through mPCR. Between September and November 2019, 150 ready-to-eat chicken doner samples (75 of them ready to consume, the other 75 packed in a modified atmosphere) were analyzed. It was found that 23 of the 150 (15.3%) samples analyzed were contaminated with Salmonella spp. 73 isolates were obtained from 23 positive samples. Of these 73 isolates, 33 were found to be Salmonella spp. positive. In serotyping, all 33 isolates were determined to be S. infantis. In the antibiotic resistance profile, 30 of theisolates were resistant to chloramphenicol, 24 to gentamicin, 21 to ampicillin, 20 to trimethoprim-sulfamethoxazole and ciprofloxacin, 18 to tetracycline and amoxicillin-clavulanic acid, and 13 to cefoxitin. As a result, the isolation of Salmonella spp. from the samples and their resistance to different antibiotics were evaluated as potential sources of problems in the context of foodborne infectious diseases.

Pseudomonas aeruginosa (P. aeruginosa), the most pathogenic species among the pseudomonas species, is a bacterium that causes opportunistic infections resulting in significant damage to host tissues. P. aeruginosa, which is resistant to antibiotics, also causes fatal infection in human and animals. Infections caused by P. aeruginosa are difficult to treat due to its rapid proliferation in the environment and its ability to form biofilms that confer resistance to antibiotics. One of the main virulence factors of P. aeruginosa is its direct damage to host tissues, which disrupts the host’s defense mechanisms. P. aeruginosa is a food-borne pathogen often detected in various food groups such as meat, milk, fruit, vegetables, and water. In recent years, there has been a noticeable rise in food-borne contamination with P. aeruginosa. New measures are urgently needed in the treatment of patients with infections due to this agent, since P. aeruginosa can develop resistance to most antibacterials. In this review, general information about P. aeruginosa, which has gained importance for public health, will be given.

Microbial and chemical contamination is one of the biggest environmental problems since exposure to pathogenic microorganisms, such as food poisoning bacteria and their biological by-products, are often associated with disease and allergic reactions. Paenibacillus lautus is an aerobic or facultative anaerobic opportunistic bacterial pathogen, which is found in a variety of sources. In this study, we isolated and characterized P. lautus from Niğde Province, which is a wastewater disposal area and therefore presents a great source of contamination. The bacterial isolate was grown, colony morphology and Gram-reactions were observed. Bacteria were identified by 16S rDNA sequencing analysis, which was performed using DNA samples isolated from pure cultures and amplified by polymerase chain reaction (PCR). Sequencing results were compared against known bacterial strains using BLAST (Basic Local Alignment Search Tool) across databases. Antibiotic resistance against 20 different antibiotics and heavy metal resistance against different concentrations of zinc, copper, iron, cobalt, chromium and silver containing compounds were tested via disk diffusion method. Inhibition zones were examined and minimum inhibitory concentrations were recorded. Our results indicated that P. lautus was resistant to a certain set of antibiotics, while it was sensitive against others. Similarly, the bacteria were resistant against high concentrations of most metals tested. In summary, this study provided the first data regarding the isolation and characterization of Paenibacillus lautus strain from a local source in Turkey, which will account as preliminary data and guide our future efforts to fight against microbial contaminations.

Antibiotic resistance is being constantly developed worldwide. Coagulase Negative Staphylococci (CNS) and Staphylococcus aureus are common causes of bovine subclinical mastitis. Bioactive compound of medicinal plants shows anti-microbial, anti-mutagenic and anti-oxidant effects. The anti-bacterial and anti-oxidant activities of Liquidambar orientalis (L. orientalis) extracts on subclinical mastitis causing bacteria in cows have not been reported to date. The aim of the present study was to examine anti-bacterial and anti-oxidant effects of L. orientalis leaf extracts on S. aureus and CNS isolated from cows with subclinical mastitis symptoms. In this study, 3.2 mg/mL minimum inhibitory concentration (MIC) of ethanol extracts of L. orientalis has shown to be a most potent anti-bacterial and anti-oxidant for all isolated bacterial species from mastitis cows. In this study, it was investigated anti-bacterial and anti-oxidant potentials of acetone, methanol and ethanol extracts of the L. orientalis. The acetone extract showed maximum inhibition zone against S. aureus numbered 17 (12 mm). In addition to anti-bacterial properties, anti-oxidant activity of L. orientalis extract was examined by ABTS [2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid)] free radical assay. Trolox was used as a positive control anti-oxidant. Ethanol extract exhibited a strong anti-oxidant activity like Trolox anti-oxidant which was effective at 2.58 mM concentration. Bioactive compounds of sweet gum may be useful to screening mastitis causing bacteria for clinical applications.

Probiotics are widely used in different forms of food or food supplements due to their health benefits. Probiotics consumption has seen an increase over the years. The main species used in probiotic products are Lactobacillus and Bifidobacterium, along with other species such as Bacillus. Generally, probiotic microorganisms are accepted as safe even though they are resistant to several antibiotics. Some probiotic strains with intrinsic antibiotic resistance may be beneficial in regenerating gut microbiota during antibiotic therapy. However, the antibiotic resistance genes identified in probiotic microorganisms may carry the risk of the transfer of resistance genes to pathogens, raising concerns. For instance, tetracycline resistance genes have often been detected in probiotic organisms Bifidobacterium and Lactobacillus. The antibiotic resistance genes carried on mobile genetic elements create reservoirs for pathogen resistance. This transfer of resistant genes to opportunistic pathogens and their spread may pose great danger. Hence, the purpose of this review was to assess the presence of antibiotic resistance in probiotic microorganisms and the potential transfer of the resistant genes to pathogens or commensal bacteria in the intestine.

This study was conducted to determine the Listeria monocytogenes’s presence, serotypes and resistance against various antibiotics in modified atmosphere packaged (MAP) ground and cubed beef samples. Five of ground (5/50-10%) and 3 of cubed beef samples (3/50-6%) were identified as L. monocytogenes positive in MAP samples. Eleven L. monocytogenes isolates that obtained from samples being investigated in term of hlyA gene by PCR method have verified that this gene (100%). In serotyping results, 3 of 8 isolate that obtained from MAP ground beef samples were 1/2a, the other 3 isolate was 1/2b and the remaining 2 isolate was 4b. Also, 1 of 3 isolate that obtained from MAP cubed beef samples were 1/2b, the other one isolate was 1/2c and the last one was 4b. One isolate against (9%) ampicillin, 2 isolate against (18.2%) chloramphenicol, 3 isolate against (27.2%) erythromycin, 4 isolate against (36.3%) oxytetracycline and 4 isolate against (36.3%) penicillin G, 6 isolate against (54.5%) tetracycline and 3 isolate against (27.2%) vancomycin was resistant in 11 L. monocytogenes isolates that confirmed by PCR. The L. monocytogenes isolates were found to be resistant to one or more antibiotics in antibiotic-resistance test results. In conclusion, applying of national residue monitoring program by official authority for prevention of intensive antibiotic use in order to prevent the development of resistant strains to antibiotics has great importance.

The traditional fermented food consumption has become very popular because of the increasing public concern about food additives. Lactic Acid Bacteria (LAB) species have traditionally been used as starter cultures in the production of fermented food. LAB can acquire antibiotic resistance from other bacteria in the natural environment and different resistant mechanisms via mutation. The resistance of bacteria to antibiotics is an increasingly important public health problem worldwide. In this study, antibiotic resistance of 115 Streptocoocus thermophilus and 35 Lactobacillus bulgaricus isolates obtained from traditional Turkish yogurts were tested against kanamycin, chloramphenicol, erythromycin, ampicillin, rifampicin, tetracycline, vancomycin and gentamicin using disc diffusion method. Study results showed that most strains were susceptible to all the antibiotics tested while a few of them were determined to be resistant only to kanamycin, ampicillin, erythromycin, and tetracycline. When contacted in a human body, resistant strains might transfer the related genes to the pathogenic species, which may result in devastating consequences.