Mukaddes Barel

Carvacrol, a phenolic monoterpene from oregano ( Origanum spp.), is increasingly investigated as a natural antimicrobial in poultry preservation, yet its simultaneous effects on the chemical composition, microbiota, and consumer dietary safety of treated meat remain uncharacterised. This study characterised GC-MS profile changes in carvacrol-applied chicken breast, thigh, and wing tissues, screened microbiota shifts by using exploratory 16S rRNA gene sequencing, and estimated consumer dietary exposure using the Margin of Exposure (MOE) framework. GC-MS analysis showed that phenolics accounted for >98% of detected metabolites in treated tissues, proportionally displacing alkanes and sterols within the constant-sum profile. Microbiota profiling indicated selective compositional trends without substantial loss of alpha diversity (Shannon: 4.26–4.45), including enrichment of Metabacillus spp. and reduced relative abundance of Staphylococcus and Klebsiella . Exposure modelling using consumption data from 193 adults yielded estimated daily intakes of 0.383 and 0.612 mg kg ⁻¹ bw day ⁻¹ under typical and higher intake scenarios, with corresponding MOE values of 522 and 327, both well above the EFSA threshold of 100, indicating low toxicological concern. Carvacrol application at 1,000 mg kg ⁻¹ reshapes the chemical profile and selectively modulates the microbiota of chicken meat while remaining within established consumer dietary safety margins; culture-based verification of antimicrobial efficacy is warranted.

This study focused on the metabolic and microbiological changes induced by citicoline in kefir. To demonstrate the microbial effects of citicoline in kefir, metabolite analysis was conducted using 16S rRNA and 28S rRNA metabarcoding. Additionally, kefir metabolite analysis was performed using gas chromatography–mass spectrometry (GC–MS). As a result of 16S rRNA analysis, the total bacterial abundances in the milk, kefir-citicoline (kefir-CT), and kefir samples were detected at rates of 82.83%, 79.23%, and 88.72%, respectively. The most dominant species in milk and kefir-CT samples were Halorubrum sp., accounting for 9.03% and 10.98%, respectively, whereas the most predominant species in kefir samples was Halostella sp. (9.5%). As a result of 28S rRNA analysis, the most dominant species in milk, kefir-CT, and kefir were Candida albicans (76.8%), (65.3%), and (67.68%), respectively. Furthermore, the GC–MS method was used to characterise the qualitative and quantitative changes of metabolites in milk, kefir, and kefir-CT samples and to determine the differences between the samples. As a result, a total of 25 different compounds were detected in these samples. Metabarcoding and GC–MS analyses have shown that citicoline use alters bacteria, yeast, and total volatile components. However, the addition of novel ingredients to foods with a wide range of health benefits, given their high diversity, creates opportunities for scientific research and diverse applications in the food market. Nevertheless, further research is needed in the future to understand the mechanisms within the body and in foods before these supplements can be added to foods or replace their natural variants.

Antimicrobial resistance in various infectious agents represents a public health threat. Therefore, the use of antimicrobials reveals new resistance mechanisms, and these resistance mechanisms are spreading globally. In this study, the aim was to isolate Escherichia coli from samples by conventional culture method and to identify the E. coli isolates obtained by PCR analysis. As a result of the culture method, 120 of 300 samples (40%) were isolated as suspected E. coli . However, the detection of the trpA gene only in 90 (75%) of the isolates allowed for the confirmation that it was, in fact, E. coli . According to PCR results, a total of 10 (11%) isolates were identified as E. coli subgroups. Eight (80%) of these isolates were found to be E. coli O157:H7 positive, while two (20%) were found to be E. coli O157 positive. In addition, five (50%) isolates were found to be H7 positive. Antimicrobial effect (Enzyme‐Linked Immuno Sorbent Assay) was determined using the ELISA method. The results show that the CuONPs at 0.085 µg/mL had antibacterial properties against all strains. Antibiotic susceptibility was tested using the disc diffusion method. Nine (10%), 6 (6%), 28 (31%), 24 (26%), 5 (5%), 8 (8.8%), 4 (4%) and 6 (6%) tetracyclines, erythromycin, gentamicin, azithromycin, imipenem, ampicillin and nalidixic acid were found to be resistant, respectively. According to the results of the analysis, 1 and mcr 5 gene levels were found in 10 (11%) and 2 (2.2%) isolates, respectively. Also, in the isolates, E. coli O157:H7 had mcr 1 and mcr 5 genes in levels 3 (37.5) and 2 (25%). Nonetheless, 2 (100%) E. coli O157 isolates carried the mcr 1 gene, while 4 (80%) H7 isolates carried the mcr 1 gene. In this study, virulence genes were detected in all E. coli O157:H7 isolates. According to Congo red agar, two E. coli isolates were found to have strong biofilm formation ability, while three E. coli isolates were found to have moderate biofilm formation ability. The results of this study, due to the antimicrobial resistance, virulence genes and biofilm formation abilities of the strains, emphasize that these strains pose a significant risk to public health because they are associated with foodborne diseases and that this situation poses a danger of spreading the resistance gene in the environment.

The objectives of the study were to determine the prevalence of carbapenem-resistant Gram-negative bacteria and assess the potential risks associated with cattle slaughterhouse wastewater. A total of 270 wastewater samples were collected from 10 different cattle slaughterhouses for microbiological analysis. Conventional culture methods were employed, followed by disc diffusion, the Modified Carbapenem Inactivation Method (mCIM), and the Modified Hodge Test (MHT) to identify carbapenem resistance. The Vitek® 2 compact system was used for species identification and antibiotic susceptibility profiling. Conventional and quantitative PCR (qPCR) were performed to detect specific carbapenemase genes (blaKPC, blaNDM, and blaOXA-48), among the collected 17 (6.30%) carbapenem-resistant isolates, one Pseudomonas fluorescens (0.37%), one Aeromonas hydrophila (0.37%), and two Aeromonas sobria (0.74%) exhibited resistance to meropenem. Additionally, six P. fluorescens (2.22%) and two A. hydrophila (0.74%) isolates demonstrated intermediate resistance to meropenem. Furthermore, five carbapenem-resistant isolates were identified as Stenotrophomonas maltophilia (1.85%), known to be inherently resistant to most antibiotics. Ten different antibiotics were evaluated in the antibiotic resistance panel and all Aeromonas isolates were found to be resistant to cefazolin and one A. hydrophila was detected as multi-drug resistant. The revealed data indicates that slaughterhouse wastewater can serve as a reservoir for antibiotic-resistant opportunistic pathogens. However, it may not pose a substantial risk for the distribution of carbapenemases, thereby mitigating concerns related to potential public health and environmental hazards associated with this aspect of slaughterhouse operations. This study contributes to understanding of antibiotic resistance in livestock-related environments and underscores the importance of continued monitoring and surveillance.

The study aimed to assess Campylobacter jejuni prevalence in chicken meat, biofilm formation, virulence factors, antibiotic resistance, and molecular typing. In the study, 200 chicken meat samples were collected from local outlets and 51 (25.5%) isolates were identified as C. jejuni. Resistance rates to ampicillin, tetracycline, sulfamethoxazole/trimethoprim, and ciprofloxacin were 59%, 60%, 64%, and 64% respectively. Many of the isolates (49%) exhibited multidrug resistance. Beta-lactamase and tetracycline resistance genes were found in 82.3% and 86.2% of isolates, respectively. Virulence genes were detected in various proportions. Biofilm formation was weak to moderate. ERIC-PCR showed varied band profiles. Whole genome sequencing confirmed findings. The study highlights C. jejuni presence with antibiotic resistance, virulence and biofilm features in chicken meat, posing public health risks.

Antimicrobial resistance occurring in a wide variety of Gram negative bacteria is considered an ongoing public health threat. For this reason, unconscious use of antimicrobials reveals new resistance mechanisms, and these resistance mechanisms are spreading globally. Due to these reasons, our current study aimed to isolate colistin-resistant Escherichia coli in raw meat samples and molecular characterization of resistance genes. For this purpose, the trpA gene was detected in 90 (75%) of the E. coli isolates obtained from 300 samples. mcr-1 gene was found in 8 (8.8%) of the isolates confirmed as E. coli. However, as a result of the PCR analysis, O45:H2, O103:H2, O121:H19, O145:H28, O26:H11, O111:H8 E. coli serogroups and virulence genes were not found in any isolate. Additionally, isolates 7 (7.7%), 5 (5.5%), 29 (32.2%), 23 (25.5%), 8 (8.8%), 10 (9%), 2 (2.2%) and 6 (6.6%). It was found to be acid resistant to tetracycline, erythromycin, gentamicin, azithromycin, imipenem, ampicillin, and nalidixic acid, respectively.

Sentetik antibiyotiklere karşı artan antimikrobiyal direnç, doğal olarak oluşan bileşiklerin etkili antibakteriyel ajanlar olarak kullanılması bilim insanlarının ilgisini çekmiştir. Doğal olarak oluşan bileşiklerden Hesperidin'in farklı patojen bakterilere karşı da etkili olabileceği, bakteriyel büyümeyi doğrudan engelleyebileceği belirtilmiştir. Bu çalışmada, Hes-peridin’in bazı ATCC suşlarına (Escherichia coli ATCC 25922, Escherichia coli O157;H7 ATCC 43895, Salmonella enteriditis NCTC, Klebsiella pneumonie ATCC 1705, Aeromonas hydrophila ATCC 7966) karşı etkinliğinin belirlenmesi amaçlanmıştır. Yapılan minimal inhibisyon konstrasyon (MİK) testi sonuçlarına göre Hesperidin için E. coli, E. coli O157;H7, S. enteriditis ve K. pneumonie bakterilerine ait MİK değerleri 128 μg/mL iken, A. hydrophila bakterisine ait MİK değeri 64 μg/mL olarak belirlenmiştir. Bu sonuçlara ek olarak, pozitif kontrol kolistin için E. coli, K. pneumonie ve A. hydrophila bakterilere ait MİK değerleri 0.5 μg/mL olarak belirlenirken, E. coli O157;H7 ve S. enteriditis bakterilerine ait MİK değerleri sırasıyla 0.5 ve 1 μg/mL olarak belirlenmiştir. Bu çalışma sonuçları Hesperidin’in özellikle su ürünleri yetiştiriciliğinde koruyucu ve alternatif bir antibakteriyel tedavi seçeneği olarak yenilikçi kanıtlar sunabilir.

Bu çalışmada; Kayseri ilinde satışa sunulan tavuk eti örneklerinden Arcobacter spp’nin izolasyonu, identifikasyonu ve elde edilen izolatların antibiyotik duyarlılıklarının belirlenmesi ve moleküler tiplendirilmesi amaçlanmıştır. Bu amaçla, tavuk eti satış noktalarından toplanan toplam 100 adet tavuk eti örneği materyal olarak kullanıldı. Arcobacter spp.’lerin izolasyonu amacıyla ön zenginleştirme ve membran filtrasyon metodundan yararlanıldı. Elde edilen Arcobacter spp. izolatlarının identifikasyonu fenotipik testler ve Multipleks Polimeraz Zincir Reaksiyonu (mPZR) ile gerçekleştirildi. Arco- bacter spp. izolatların eritromisin azitromisin, enrofloksasin, tetrasiklin, ampisilin, trimetoprim-sulfametoksazol, amoksi- silin-klavulanik asit, gentamisin, streptomisin, neomisin antibiyotiklerine karşı duyarlılıklarının saptanması amacıyla disk difüzyon testi yönteminden yararlanıldı. Arcobacter spp. izolatlarının genotiplendirilmesi Enterobacterial Repetitive Intergenic Consensus-Polymerase Chain Reaction (ERIC-PCR) ile gerçekleştirildi. Bu çalışmada, izolasyon işlemi so- nucunda toplanan 100 adet tavuk eti örneğinin 23’ü (%23) Arcobacter spp. yönünden pozitif bulundu. Moleküler identi- fikasyon sonucunda, elde edilen, 23 Arcobacter spp. izolatının 3’ü Arcobacter cryaerophilus, 20’si ise Arcobacter butzleri olarak tanımlandı. Antibiyotik duyarlılık testi sonucunda, Arcobacter spp. izolatlarının sırasıyla 12’sinin (% 52.17) eritromisine, 13’ünün (%56.52) amoksisilin-klavulanik asite, 20’sinin (%86.95) trimetoprim/sülfametaksazole, 20’sinin (%86.95) ampisiline, 8’inin (%34.78) enrofloksasine, 2’sinin (%8.69) tetrasikline, 5’inin (%21.73) streptomisine, 16’sının (%69.56) azitromisine ve 21’inin (%91.3) de neomisine dirençli olduğu tespit edildi. Ayrıca tüm izolatların gen- tamisine duyarlı olduğu belirlendi. Sonuç olarak, çoklu antibiyotik dirençli olduğu belirlenen Arcobacter spp.’nin yaygın olarak tüketilen kanatlı etinde bulunması, insanlarda gastroenterit ve bağırsak dışı hastalıklara neden olan bu etkenle- rin halk sağlığı açısından risk oluşturabileceğini göstermektedir. Bu nedenle kanatlı karkaslarının etken ile kontaminas- yonun önlenmesi ve gıdaların üretimi, işlenmesi, depolanması ve satışı hakkında personelin eğitilmesinin, kanatlı etle- rinden kaynaklanan hastalıkları engellemekte önemli rol oynayacağı düşünülmektedir.

Arcobacter spp. has gained clinical significance as an emerging diarrheagenic pathogen associated with water reservoirs in recent years. The complete clinical significance of Arcobacter remains rather speculative due to the virulence and antibiotic susceptibility of individual strains. This study aimed to assess the prevalence of Arcobacter spp. in fish, water, and shellfish. A total of 150 samples were collected from the Adana, Kayseri and Kahramanmaras provinces in Turkey. Arcobacter spp. was isolated from 32 (21%) of the 150 samples. The most prevalent species was A. cryaerophilus, 17 (56%), A. butzleri 13 (37%) and A. lacus 2 (6%). As a result, the ratios of the mviN, irgA, pldA, tlyA and hecA target genes were found as 17 (51%), 1 (3%), 7 (23%), 7 (23%), 1 (3%), respectively. While bla OXA-61, tetO and tetW were positive in all isolates, were found as mcr1/2/6, mcr3/7, and mcr5, genes %37.5, %25, and %34.3, respectively. Although in A. butzleri was found 10 (58%), 1 (3%), 3 (43%), 2 (28%) (mviN, irgA, pldA, and tlyA, respectively) virulence genes 7 (42%), 4 (57%), 5 (72%), 1 (3%) was found (mviN, irgA, tlyA, and hecA, respectively) virulence genes in A. cryoaerophilus. Moreover, was found for the mcr 1/2/6 7 (58%) genes, for the mcr 3/7 genes 3 (38%) in A. butzleri. In A. cryoaerophilus was found for the mcr 1/2/6 genes 5 (42%), for the mcr 3/7 genes 5 (62%), and for the mcr 5 gene 10 (100%). Thus, the current study indicated that the existence of Arcobacter spp. isolated from fish and mussel samples may pose a potential risk to public health.