Production, characterization and therapeutic efficacy of egg yolk antibodies specific to Nosema ceranae.

Nosema disease, caused by Nosema ceranae, one of the single-celled fungal microsporidian parasites, is one of the most important and common diseases of adult honey bees. Since fumagillin, which has been used for decades in the control of Nosema disease in honey bees (Apis mellifera), poses a toxic threat and its efficacy against N. ceranae is uncertain, there is an urgent need to develop alternative prophylactic and curative strategies for the treatment of this disease. The main aim of this study was to investigate the therapeutic potential of specific egg yolk immunoglobulins (IgY) on Nosema disease. For this purpose, the presence of N. ceranae was determined by microscopic and PCR methods in honey bees collected from Nosema suspicious colonies by conducting a field survey. Layered Ataks chickens, divided into four groups each containing 20 animals, were vaccinated with live and inactivated vaccines prepared from field isolates of N. ceranae. Eggs were collected weekly for 10 weeks following the last vaccination. IgY extraction was performed using the PEG precipitation method from egg yolks collected from each group, and the purity of the antibodies was determined by SDS-PAGE and Western Blot. The presence of N. ceranae-specific IgYs was investigated by Western Blot and indirect ELISA methods. It was determined that specific IgYs showed high therapeutic efficacy on Nosema disease in naturally infected bee colonies. In addition, honey bees collected from infected colonies were brought to the laboratory and placed in cages with 30 bees each, and the effectiveness of IgYs was investigated under controlled conditions. It was detected that specific IgY reduced the Nosema spore load and the number of infected bees significantly in both the field and experimental study groups treated for seven days. It was concluded that chicken IgYs, an innovative and eco-friendly method, had a significant potential for use as an alternative to antifungal drugs.

Knowledge, Attitudes, Practices and Some Characteristic Features of People Recovered from COVID-19 in Turkey.

Background and objectives: The whole world is spending an extraordinary effort by implementing various measures to control and prevent the COVID-19 pandemic. The effectiveness of the preventive measures is greatly influenced by the public's knowledge, attitudes, and practices (KAP) towards the disease. In this study, KAP values and some characteristic features of people recovered from COVID-19 were determined by conducting a questionnaire survey. Materials and Methods: The questionnaire survey was conducted between 1 and 10 January 2021 on people who recovered from COVID-19 in a total of 150 different locations in Turkey. The questionnaire consisted of 46 questions: 14 for determining demographic and some characteristic features of the participants, and 32 for determining their knowledge, attitudes, and practices. The data obtained were evaluated using descriptive statistics, chi-squared tests, t-tests, and one-way analysis of variance (ANOVA). Results: It was determined that 63% of the participants had at least one chronic illness, 3.9% suffered from the disease twice, and 45.2% changed their smoking habits. The average knowledge score of the participants about COVID-19 was calculated as 10.25 (SD = 2.37; range 0-15). The participants were found to have a high level of knowledge about the symptoms and prevention methods in general, and positive changes in post-illness attitudes and behaviors. However, there was a great instability regarding the drugs and vaccines used in the treatment of COVID-19. Conclusions: This was the first study carried out in Turkey to determine knowledge, attitudes, practices, and some characteristic features of people who recovered from COVID-19. It was suggested that health authorities in the country need to develop more effective strategies and policies to find out permanent solutions in order to control and prevent the COVID-19 pandemic by taking into account the concerns of the public, particularly with regards to the drugs used in the treatment and vaccination.

Assessment of Farmers' Knowledge, Attitudes and Practices on Antibiotics and Antimicrobial Resistance.

The aim of this study was to determine knowledge, attitudes, and behaviors of farmers dealing with animal husbandry in eastern Turkey with regard to antibiotic knowledge, use, and resistance. A face to face questionnaire survey, consisting of five sections with 42 questions in total, was applied to 360 farmers located in the region. The questions in the first and fifth sections were closed-ended while those in other sections were prepared using the Likert scale. It was determined that knowledge of the farmers about antibiotic use, duration, storage, and resistance was well below desired levels. This was particularly remarkable in the participants with a low level of education, living in rural areas, and those at 48 years of age or over. In contrast, younger and highly educated participants living in urban areas were more knowledgeable about antibiotic use and they were well aware of the fact that resistance might pose a great risk for public health. Providing appropriate antibiotic use in animals through systematic training of livestock farmers is crucial in tackling the resistance problem.

The first experimental research on the pathogenicity of Arcobacter butzleri in zebrafish.

This experimental study was conducted to investigate the pathogenicity and histopathology of Arcobacter butzleri in zebrafish model organism. Firstly, mean infective dose (ID50) of A. butzleri was calculated in zebrafish as 1.3×10(8)CFU/mL and 1×10(5)CFU/mL by immersion and intraperitoneal injection, respectively. For histopathological trials, the ID50 of A. butzleri were given to zebrafish by both immersion and intraperitoneal routes and then, clinical and pathological findings were evaluated on days 1, 3, 5, 7 and 21 of the experiment. During the experimental period, no clinical signs or gross lesions of disease were observed in the zebrafish groups infected with the ID50 of A. butzleri by either method. In the histopathological examination, acute inflammation characterized by neutrophil and plasma cells and local necrosis or congestion were determined in liver, kidney, spleen, gaster and other visceral organs. In addition peritonitis, leukocyte infiltration, villous atrophy and septicemia were observed in the experimental groups. Neither gross nor microscopic lesions were detected in the control groups. This study presented the first report of experimental A. butzleri infection in wild zebrafish. In the light of the findings obtained here, it was concluded that zebrafish could be used as a model organism to investigate pathogenicity and histopathology of arcobacters.

Investigation of toxin genes by polymerase chain reaction in Staphylococcus aureus strains isolated from bovine mastitis in Turkey.

Staphylococcus aureus causes a number of diseases in humans and animals, and it is the most common etiological agent of contagious bovine mastitis. The agent produces several virulence factors such as coagulase (coa), clumping factor, protein A, exfoliative toxins, staphylococcal enterotoxins (SEs), and toxic shock syndrome toxin-1. The aim of the present study was to characterize coa-positive S. aureus strains (n = 92) isolated from bovine subclinical mastitis in Turkey by polymerase chain reaction (PCR) amplification of exfoliative toxin (eta and etb) and toxic shock syndrome toxin-1 (tsst) genes. In addition, a multiplex PCR was employed to investigate the presence of SE genes sea, seb, sec, sed, see, seg, seh, sej, and sei. By PCR amplification, while eta and etb were not detected, only three isolates (3.3%) were positive for tsst. Twenty-seven (29.3%) isolates harbored one or more SE genes, and sei was the most common pattern by multiplex PCR. None of the isolates harbored the genes encoding sea, see, and seh. The application of this multiplex PCR assay could enable more samples to be rapidly characterized for enterotoxin production of S. aureus isolates from milk for epidemiological studies.

Heterogeneity of Campylobacter jejuni and Campylobacter coli strains from healthy sheep.

The objectives of this study were to identify, at species level, thermophilic campylobacters isolated from clinically healthy sheep by a multiplex polymerase chain reaction (mPCR). The heterogeneity among Campylobacter jejuni and C. coli isolates was also investigated using a restriction fragment length polymorphism (RFLP) analysis of the flagellin (flaA) gene. Samples of intestinal contents, gall bladders and faeces were collected from 610 healthy sheep. While gall bladder samples were plated directly onto Preston agar, an enrichment stage was applied for intestinal and faecal samples. Of the 610 samples, 302 (49.5%) were positive for Campylobacter spp. Using a mPCR assay for species identification, 103 (34.1%) were positive with C. jejuni-specific primers, while 100 (33.1%) were positive with C. coli-specific primers. Additionally, 16 (11.9%) of the intestinal content samples were positive for both species by mPCR. All the isolates identified as C. jejuni and C. coli were successfully subtyped by flaA typing. Of 203 isolates tested, 48 different flaA types were found. Twenty-six flaA types were identified among C. jejuni isolates and the remaining 22 from C. coli isolates.

Random amplified polymorphic DNA analysis of Campylobacter jejuni and Campylobacter coli isolated from healthy cattle and sheep.

The genetic heterogeneity among Campylobacter jejuni and Campylobacter coli isolates obtained from apparently healthy cattle and sheep was investigated by random amplified polymorphic DNA (RAPD) analysis. A total of 348 Campylobacter isolates, consisting of C. jejuni (n = 218) and C. coli (n = 130), were analysed. All these isolates were successfully typed by RAPD analysis. The total numbers of band patterns defined by RAPD in cattle and sheep were 42 and 45, respectively. Of the 42 distinct types obtained from cattle, 37 types were observed in C. jejuni isolates (n = 115), and the remaining 5 were in C. coli isolates (n = 30). Of 45 distinct types obtained from sheep, 21 types were observed in C. jejuni isolates (n = 103), and 24 were in C. coli isolates (n = 100). It was concluded that a high degree of heterogeneity existed among the C. jejuni and C. coli isolates of healthy cattle and sheep.