Barış Halaç

Objective: This in vitro proof-of-concept study evaluated the antimicrobial activity of niaouli (Melaleuca quinquenervia) essential oil and assessed its time-dependent efficacy when incorporated into the absorbent middle layer of sanitary and incontinence pads. Methods: Minimum inhibitory concentrations (MICs) were determined against six UTI-associated pathogens (including E. coli and S. aureus) using the broth microdilution method (CLSI). Oil-impregnated pad samples were subsequently evaluated in a quantitative time-dependent assay over six hours. Results: Niaouli oil showed moderate activity against E. coli and K. pneumoniae (MIC = 104 µg/mL) and weaker activity against S. aureus, S. epidermidis, and C. albicans (MIC = 3333 µg/mL). In the pad matrix, bactericidal reductions (≥3 log₁₀ CFU/mL) were sustained for 2 hours against Gram-negative bacteria and 3 hours against Gram-positive strains. However, a complete loss of efficacy and subsequent microbial regrowth were observed by the 5th and 6th hours, likely due to the volatile depletion of active constituents.Conclusion: Niaouli essential oil provides significant but transient antimicrobial protection within absorbent matrices. While promising for bioactive hygiene products, further optimization, such as microencapsulation, is essential to achieve sustained clinical efficacy.

Bu çalışmada, Escherichia coli kaynaklı pyometra (Grup PYO; n=14) olan dişi köpeklerin ve sağlıklı diöstrus kontrol grubunun (Grup C; n=18) uterus dokusu ve kan serumundaki Ki-67 düzeylerini ölçerek proliferatif değişikliklerin değerlendirilmesi amaçlandı. Çalışma ayrıca proliferatif değişiklikler ile hematolojik parametreler (C-reaktif protein, tam kan sayımı, albumin ve serum progesteron ile monosit-lenfosit oranı, nötrofil-lenfosit oranı, trombosit-lenfosit oranı) arasındaki ilişkiyi incelemek amacıyla yapıldı. PYO grubunun uterus dokusunda belirlenen Ki-67 seviyesi, kontrol grubuna kıyasla daha yüksek bulundu (P

This study aimed to phenotypically and genotypically detect beta-lactam-resistant Escherichia coli in the feces of wild and migratory birds residing in or passing through the Marmara Region during seasonal migration. A total of 272 fresh fecal samples were non-invasively collected and grouped as follows: (1) resident wild waterfowl, (2) resident urban birds (e.g., pigeons, crows, sparrows), (3) migratory birds overwintering in Turkey, and (4) migratory birds staying during spring and summer. Samples were cultured on MacConkey agar with and without cefotaxime (1 mg/L). Carbapenem resistance was assessed using the Modified Hodge Test; none of the 212 isolates tested positive. Among the 272 birds sampled, 62 (22.8%) carried ESBL and/or AmpC producing isolates. Antimicrobial-resistant E. coli were identified in 59 of 272 birds (21.7%), including 47 ESBL-positive, 6 AmpC-positive, and 5 harboring both resistance types. Group 1 (mainly gulls) showed the highest resistance rates. PCR analysis revealed that among 84 isolates, 48 carried only beta-lactamase genes, 3 only AmpC genes, and 5 both. Detected genes included: bla _CTX-M ( n = 50), bla _SHV ( n = 2), and bla _OXA10 ( n = 10); for AmpC: bla _MOX ( n = 6) and bla _CIT ( n = 2). Species-specific results confirmed the highest frequency of resistance genes in gulls. The Frequency of resistant isolates was significantly higher in Groups 1 and 2 ( P < 0.001). The resistance profiles identified in gulls especially those feeding at landfills or in direct contact with human, animal, and agricultural waste suggest a likely anthropogenic and/or zoonotic origin of the beta lactam resistance observed in this study conducted in Marmara Region.

Enterococcus species were initially regarded as primary commensal microorganisms constituting a major component of the gastrointestinal microbiota in avian and mammalian hosts. However, over the years, pathogenic Enterococcus strains have emerged as significant causes of morbidity and mortality in broiler production, frequently leading to recurrent outbreaks. Enterococcus spp. also act as opportunistic pathogens, responsible for septicemia, endocarditis, osteomyelitis, and neurological disorders in poultry and parrots. Enterococcus are particularly notable for their remarkable capacity to develop and disseminate antimicrobial resistance. Among them, vancomycin-resistant Enterococcus (VRE) pose a serious, life-threatening concern for both animal and human health. Furthermore, the routine and periodic use of antibiotics in poultry farming has promoted the emergence of multidrug-resistant strains, thereby limiting treatment options and heightening zoonotic risks. Comparative genomic analyses have demonstrated that highly pathogenic Enterococcal strains exhibit strong genetic relatedness and share numerous virulence-associated genes. These pathogenic strains typically display higher antimicrobial resistance levels than their commensal counterparts. In this state-of-the-art review, we examine the current understanding of the distribution patterns, pathogenic potential, and antimicrobial resistance profiles of Enterococcus strains derived from poultry, emphasizing the importance of multidisciplinary approaches and their global implications for animal and public health. Our conclusions emphasize the urgent need for stricter regulations governing antibiotic use in poultry production and the development of innovative strategies to mitigate the escalating threat posed by antibiotic-resistant Enterococcus strains. We further highlight the necessity of adopting a comprehensive, multidisciplinary “One Health” approach to promote effective solutions within veterinary medicine and safeguard both animal and human health.

Botulizm hastalığına neden olan asıl etken C. botulinum’dur. Ancak C. baratii ve C. butyricum’unda botulinum toksini ürettiği ve hastalığa neden olduğu belirlenmiştir. C. botulinum Gram pozitif, sporlu, çomak şekilli bir bakteridir. Botulinum toksini üreten Clostridium türleri 6 grupta toplanmıştır. C. botulinum Grup I, Grup II, Grup III ve Grup IV, C. baratii ve C. butyricum. Hayvanlarda botulizm Grup III ve C, D, C/D ve D/C mozaik serotipleri nedeniyle oluşmaktadır. Kanatlılarda tipA, tipC ve Grup III’e bağlı enfeksiyonlar şekillenmektedir. Kuşlarda bacaklardan başlayan ve tüm vücuda yayılan gevşek felçlerle karakterizedir. Kesin tanı için felç harici bir bulgu yoktur ve tanı çoğu zaman toksinin varlığı ile saptanmaktadır. Aşılar ve düzenli dezenfeksiyon ile hastalığın kontrolü kapalı popülasyonlarda sağlanabilmektedir.

A 5-year-old, intact female Caucasian Shepherd dog was brought to our clinic with complaints of ongoing vaginal bleeding, weakness, loss of appetite, and a vaginal mass for a month. According to the anamnesis, the vaginal mass had rapidly increased in size over the last month, and there was ulceration and bleeding on the mass. In the examination, it was determined that the mass originated from the ventrolateral surface of the vagina, and an abscess-like structure was also found cranially to this mass. The mucous membranes were light pink, the palpable lymph nodes were of average size, the furs were matte, and the vaginal area was dirty with blood. The dog’s hemogram and biochemical test results were found to be within normal reference ranges; hence, it was decided to treat the dog surgically. The tissue obtained after vaginal mass excision was examined microbiologically and histopathologically. The mass, initially thought to be an abscess based on its smaller size and macroscopic examination, was determined to have a sterile content and to be an inflammatory infiltration rather than an abscess. It was concluded that detailed clinical examination and histopathological analysis can establish the diagnosis of all tumoral cases like this, and successful treatment can be achieved through surgical intervention.

The issue of nosocomial infections, or healthcare-associated infections (HAIs), remains a significant concern in healthcare settings worldwide. In recent times, there has been growing attention towards medical devices, notably stethoscopes, as potential vectors for pathogen transmission. This study aimed to evaluate the prevalence of Staphylococcal contamination on stethoscopes used by students and staff at Istanbul University-Cerrahpasa Faculty of Veterinary Medicine’s animal hospital. Furthermore, it gathered information about stethoscope usage habits, cleaning practices, handwashing routines, participants' knowledge about nosocomial infections, and their interest in learning more about these infections and stethoscope hygiene. The analysis of 50 stethoscope samples revealed that 27 (54%) were contaminated with one or more Staphylococci. The isolated 30 Staphylococcus spp. included Staphylococcus epidermidis (n=17; 56.7%), Staphylococcus hominis (n=10; 33.3%), Staphylococcus pasteuri (n=1; 3.3%), Staphylococcus capitis (n=1; 3.3%), and Staphylococcus schleiferi (n=1; 3.3%). Notably, the absence of the highly pathogenic Staphylococcus aureus in all samples provides some reassurance. However, the presence of various Staphylococcus spp. raises concerns due to their pathogenic potential. These findings align with previous research on stethoscope contamination, emphasizing the persistent problem of bacterial colonization on these crucial medical devices. Despite variations in bacterial prevalence among studies, Staphylococcus spp. consistently emerge as common contaminants, emphasizing the need for comprehensive stethoscope hygiene protocols in veterinary healthcare settings. To the best of our knowledge, this is the first report describing the vector potential of stethoscopes in a veterinary setting within Turkey. The study suggests the necessity for further research, taking a proactive approach to tackle the challenges of nosocomial infections. This would enable the development of strategies to ensure a safer healthcare environment for patients and healthcare providers.

One of the biggest problems in the modern world is environmental pollution. All organisms are affected by the resulting pollution, albeit at different levels. One of the most important causes of pollution is the stable and non-perishable compounds formed due to heavy metals used in a wide range of environments. Heavy metal pollution, especially in the seas, causes cumulative accumulations in aquatic life, food and other products obtained from aquatic life, in living things that consume these products, and related diseases. The most critical sign of heavy metal pollution in water is the resistance formed against heavy metals in bacteria living in these waters. To determine the resistance to heavy metals in bacteria, the presence of resistance to Copper, Mercury and Manganese heavy metals in E. coli isolated from 18 mussels and 16 shrimps was genotypically investigated. For this purpose, the presence of pcoR genes for the determination of copper resistance, merA for the determination of mercury resistance, and mntR for the determination of manganese resistance was investigated in both plasmid and genomic DNA. As a result of the study, resistance genes were detected against heavy metals in 31 (91.17%) of 34 E. coli isolates examined. The presence of the pcoR gene (copper resistance) was found in 2 isolates (5.88%), the merA gene (mercury resistance) in only one isolate (2.94%) and the mntR gene (manganese resistance) in 8 isolates (23.52%). While pcoR and merA genes were not observed together in any isolates, pcoR and mntR genes were detected together in the genetic material of 10 isolates (29.41%). In comparison, mntR and merA genes were detected together in the genetic material of 7 isolates (20.58%). In 3 samples, all of the resistance genes against heavy metals were detected (8.82%).

The purpose of the study was to examine the prevalence of Escherichia coli in shrimps and mussels, and to determine the distribution of β-lactam, aminoglycoside, quinolone, and multi-drug resistance phenotypically and genotypically in E. coli isolates obtained from mussels and shrimps in Istanbul. Faecal samples were collected from mussels (n = 96) and shrimps (n = 96) from the Marmara Sea coastline and fish markets in Istanbul. For the detection of antibiotic susceptibilities, seven antibiotic groups were used. β-lactamase, aminoglycoside, and quinolone genes were also determined. A total of 34 (17.7%, 15 shrimps, and 19 mussels) E. coli were isolated, and 17 (50%) were found to be resistant to one or more antimicrobials. The highest resistance was seen against aminoglycosides with 11 isolates (32.35%), followed by quinolones with 10 isolates (29.41%) and extended-spectrum β-lactamase (ESBL) with 4 isolates (11.76%). Multi-drug resistance was detected in 5 isolates (14.7%) from 3 shrimp and 2 mussel samples. The prevalence of ESBL genes was demonstrated at 3.84% in mussels and shrimp samples. There were no AmpC and carbapenemase-producing genes. These samples harbored bla_CTX-M-1 (n = 3) and bla_TEM (n = 4). Ten isolates were resistant to aminoglycosides genotypically. Resistance genes detected were strB in 2 isolates, aadA in 5, strB and aadA together in 3, ANT('')-Ia, aphA1 and aphA2 simultaneously in 3, aphA1 in 1, aac(3)-IIa in 1 isolate. aac(6')-Ib-cr gene was detected in only one of 10 phenotypically resistant isolates to quinolones.