Detection of Campylobacter or Salmonella in Turkey Semen and the Ability of Poultry Semen Extenders to Reduce Their Concentrations

Methylene blue-mediated antimicrobial photodynamic therapy on chicken semen

BACKGROUND

Artificial insemination is widely employed in poultry, but high degrees of bacterial contamination are often observed in semen because of its passage through the cloaca. Consequently, most semen extenders for birds have antibiotics that could aggravate bacterial resistance.

METHODS

We evaluated the potential of antimicrobial photodynamic therapy (PDT) as an alternative to the use of antibiotics, and assessed whether changes in concentration and incubation time with methylene blue (MB), radiant exposure, and irradiance of light affect spermatozoa activity and bacteria in chicken semen.

RESULTS

Incubation with MB (< 25 µM) did not alter sperm motility, regardless of the pre-irradiation time (PIT, 1 or 5 min). Following 1 min of PIT with MB at 10 µM, samples were irradiated for 30, 60, 120, and 180 s at irradiances of 44, 29, and 17 mW/ cm² (660 nm LedBox). MB and light alone did not interfere with the analyzed parameters. However, when both factors were associated, increases in light dose led to greater reductions in sperm parameters, regardless of the irradiance used. Besides, PDT conditions that were less harmful to spermatozoa were not able to significantly reduce bacterial colonies in chicken semen.

CONCLUSIONS

A failure in MB selectivity could explain unsuccessful bacterial reduction following PDT. Further research involving other photosensitizers or conjugating molecules to MB to target microbial cells is needed for PDT application in poultry breeders.

Curcumin Attenuates Damage to Rooster Spermatozoa Exposed to Selected Uropathogens

Artificial insemination, as an essential pillar of the modern poultry industry, primarily depends on the quality of semen collected from stud roosters. Since the collection and storage of ejaculates is not a sterile process, antimicrobial agents have become essential supplements to semen extenders. While the use of traditional antibiotics has been challenged because of rising bacterial resistance, natural biomolecules represent an appealing alternative because of their antibacterial and antioxidant properties. As such, this study strived to compare the effects of 50 μmol/L curcumin (CUR) with 31.2 µg/mL kanamycin (KAN) as a conventional antibiotic on rooster sperm quality in the presence of Salmonella enterica, Escherichia coli and Pseudomonas aeruginosa. Changes in sperm structural integrity and functional activity were monitored at 2 and 24 h of culture. Computer-assisted semen analysis revealed significant sperm motility preservation following treatment with KAN, particularly in the case of Salmonella enterica and Pseudomonas aeruginosa (p < 0.001) after 24 h. On the other hand, CUR was more effective in opposing ROS overproduction by all bacteria (p < 0.05), as determined by luminol-based luminometry, and maintained sperm mitochondrial activity (p < 0.001 in the case of Salmonella enterica; p < 0.05 with respect to Escherichia coli and Pseudomonas aeruginosa), as assessed by the fluorometric JC-1 assay. The TUNEL assay revealed that CUR readily preserved the DNA integrity of rooster sperm exposed to Salmonella enterica (p < 0.01) and Escherichia coli (p < 0.001). The bacteriological analysis showed higher efficiency of KAN in preventing the growth of all selected bacterial species (p < 0.0001) as opposed to CUR. In conclusion, CUR provided protection to rooster spermatozoa against alterations caused by uropathogens, most likely through its antioxidant activity. Hence, CUR supplementation to poultry semen extenders in combination with properly selected antibacterial substances may become an interesting strategy in the management of bacterial contamination during semen storage.

Oral, Cloacal, and Hemipenal Actinomycosis in Captive Ball Pythons (Python regius)

Ball pythons (Python regius) are one of the most commonly kept and bred reptiles in captivity. In a large ball python breeding colony, a unique syndrome characterized by granulomatous inflammation of the cloaca and hemipenes (phalli) was observed in 140 of 481 (29.1%) breeding males, but only one of 1,446 breeding females. Lesions were absent in virgin males (n = 201) and virgin females (n = 293). On postmortem examination (n = 13, 12 males, 1 female), numerous well-defined mucosal and submucosal granulomas were present in the hemipenes (males) and cloaca (males and female). Extension into the coelomic cavity and liver was noted in a subset of these animals. An additional small subset of breeder animals (6/2027; 0.3%) presented with oral and mandibular swellings. Postmortem examination (n = 4, all female) showed oral lesions histologically indistinguishable from the cloacal/hemipenal lesions. Aerobic bacterial culture of a hepatic granuloma of one snake resulted in the isolation of filamentous, Gram-positive bacilli; amplification, and sequencing of the 16S rRNA gene and subsequent phylogenetic analysis of the isolate identified the bacterium as a novel species of Actinomyces. Screening of cloacal and oral granulomas using a specific, heminested 16S rRNA PCR assay confirmed the presence of the agent in all 17 snakes, as well as in cloacal swabs taken at the time of necropsy in 11/13 snakes. The Actinomyces sp. was also identified by PCR of cloacal swabs of unaffected snakes (n = 94) from the affected colony and two unrelated, grossly unaffected breeding colonies. In the affected colony, 65.5% of breeding animals (n = 23) but only 11.9% of virgin animals (n = 42) tested PCR positive, with breeding status being a significant predictor of bacterium presence (P < 0.00001). This study characterizes a granulomatous mucosal disease syndrome of breeding male ball pythons associated with a novel Actinomyces. In stark contrast to male snakes, the presence of the bacterium in both breeding and virgin females was very rarely associated with clinical disease. Though additional studies are necessary, these data suggest a role for the novel bacterium in the disease process, a predilection for clinical disease in male snakes, and the potential for sexual transmission of the disease.

Effects of different mating strategies in broiler breeder during peak and postpeak phase on subsequent broiler performance

Two experimental trials on commercial broiler (Ross-308) were conducted to evaluate the carryover effect of artificial insemination (AI) in parent flock (PF) kept in cages (C), and on floor (F) in comparison to natural mating (NM) in floored PF. A total of 900 broiler chicks were obtained from 38-week-old PF (peak production), representing C, F, and NM evenly during first trial, whereas in second trial, similar number of chicks were obtained from same PF during postpeak phase (55 wk of age). Subsequent effects of AI and NM in PF were evaluated by bacteriology, posthatch mortality, growth performance, immune response, and carcass traits on experimental birds (broiler). Chicks being produced through NM exhibited significantly (P ≤ 0.05) improved growth performance (feed conversion ratio, weight gain, European efficiency factor) along with the least (P ≤ 0.05) posthatch mortality and prevalence of Escherichia coli, Salmonella Pullorum, and Mycoplasma gallisepticum. Moreover, the experimental chicks obtained from floored PF subjected to AI particularly during postpeak phase expressed the highest (P ≤ 0.05) contamination of the said pathogens along with posthatch mortality. However, immune response against New Castle disease and infectious bronchitis vaccines and slaughtering parameters remained nonsignificant (P > 0.05) among the 3 treatments under both trials. It is concluded that the best growth performance along with the least depletion and microbial load of concerned pathogens were being pertained by the experimental birds representing NM.

Effect of in ovo administration of an adult-derived microbiota on establishment of the intestinal microbiome in chickens

OBJECTIVE To determine effects of in ovo administration of a probiotic on development of the intestinal microbiota of 2 genetic lineages (modern and heritage) of chickens. SAMPLE 10 newly hatched chicks and 40 fertile eggs to determine intestinal microbiota at hatch, 900 fertile eggs to determine effects of probiotic on hatchability, and 1,560 chicks from treated or control eggs. PROCEDURES A probiotic competitive-exclusion product derived from adult microbiota was administered in ovo to fertile eggs of both genetic lineages. Cecal contents and tissues were collected from embryos, newly hatched chicks, and chicks. A PCR assay was used to detect bacteria present within the cecum of newly hatched chicks. Fluorescence in situ hybridization and vitality staining were used to detect viable bacteria within intestines of embryos. The intestinal microbiota was assessed by use of 16S pyrosequencing. RESULTS Microscopic evaluation of embryonic cecal contents and tissues subjected to differential staining techniques revealed viable bacteria in low numbers. Development of the intestinal microbiota of broiler chicks of both genetic lineages was enhanced by in ovo administration of adult microbiota. Although the treatment increased diversity and affected composition of the microbiota of chicks, most bacterial species present in the probiotic were transient colonizers. However, the treatment decreased the abundance of undesirable bacterial species within heritage lineage chicks. CONCLUSIONS AND CLINICAL RELEVANCE In ovo inoculation of a probiotic competitive-exclusion product derived from adult microbiota may be a viable method of managing development of the microbiota and reducing the prevalence of pathogenic bacteria in chickens.

Quantifying sperm egg interaction to assess the breeding efficiency through artificial insemination in guinea fowls

1. Guinea fowl hens were inseminated weekly once with two doses of spermatozoa (75 million and 100 million) in two different diluents, Beltsville poultry semen extender (BPSE), and Instruments for Veterinary Medicine (IMV), each with and without pre-insemination vaginal douching. Per cent fertility, hatchability, dead germ, dead in shells along with data on sperm egg interaction and vaginal microbial counts were recorded. 2. Artificial insemination had significantly improved the per cent fertility and hatchability compared to natural mating. Dose dependent improvement in fertility was noticed with both diluents. 3. There was a beneficial effect of vaginal douching, which was more pronounced at lower insemination doses. 4. For optimum fertility and hatchability in guinea fowl, insemination of 75 million spermatozoa diluted in BPSE once in 4 d and 100 million spermatozoa diluted in BPSE or IMV once in 5 d coupled with vaginal douching is recommended.

Impact of 6 different intestinal bacteria on broiler breeder sperm motility in vitro

Male fertility is often evaluated by measuring sperm parameters, including concentration, viability, and motility. This is important because after copulation occurs, sperm must overcome many barriers in the female reproductive tract to fertilize the ovum. In mammalian species, sperm have been shown to have reduced motility when bacteria are present. In male broiler breeders, bacteria have been associated with spermatozoa, but their effect on motility has not been investigated. The sperm quality index is a modern rapid method of evaluating avian sperm motility. Therefore, the objective of this study was to use the sperm quality index to determine if broiler breeder sperm motility is reduced when semen is exposed to various bacteria. In this experiment, semen was collected from 20 broiler breeders to obtain a pooled neat semen sample. Six different intestinal bacteria, Salmonella enterica, Escherichia coli, Campylobacter jejuni, Clostridium bifermentans, Lactobacillus acidophilus, and Bifidobacterium animalis were cultured overnight. For each bacterium, 50 µL of semen was diluted in 450 µL of saline, sterile broth, or the overnight culture, creating 3 treatments. The experiment was repeated twice. In each treatment, 3 replicates were evaluated at 0 and 10 min postinoculation, creating a completely randomized design with a split plot over time. Also, the pH was measured for each treatment at 0 and 10 min. The results indicated that all broths containing bacteria immediately reduced broiler breeder sperm motility when compared with the controls (P < 0.0001), but broths containing Bifidobacterium or Lactobacillus virtually made sperm immotile. Although broth containing Salmonella, Campylobacter, and Bifidobacterium immediately reduced sperm motility, the reduction did not change over time. Broths containing E. coli, Clostridium, and Lactobacillus reduced sperm motility immediately, but over time motility continued to decrease. However, pH was increased when semen was exposed to the E. coli and Campylobacter treatment, but when semen was exposed to Bifidobacterium and Lactobacillus treatments, pH was reduced. In conclusion, the results indicate that bacteria can reduce broiler breeder sperm motility upon exposure.

Efficacy of Iron Chelators on Campylobacter Concentrations in Turkey Semen

Campylobacter is a leading bacterial cause of human foodborne infections in the United States. Recent studies suggest that the organism is highly prevalent in poultry semen and may contribute to vertical transmission between the breeder hen and offspring. Because Campylobacter requires iron for its growth and survival, the objective of this study was to determine if the addition of natural and synthetic chelators such as ovotransferrin, desferrioxaime, EDTA, or 2,2'-dipyridyl could reduce or eliminate Campylobacter in turkey semen. In a preliminary study without semen, a commercial poultry semen extender was supplemented with various concentrations of ovotransferrin, desferrioxaime, EDTA, or 2,2'-dipyridyl and inoculated with an average of 10(8) cfu/mL of a wild-type Campylobacter coli turkey semen isolate. At 6 and 24 h of storage at 4 degrees C, a sample was taken from each treatment group and enumerated for Campylobacter. In all 3 trials, Campylobacter was undetectable (< 10(2)) in the commercial poultry semen extender supplemented with 20 mg/mL of 2,2'-dipyridyl. There were no differences observed in Campylobacter concentrations in the commercial poultry semen extender supplemented with ovotransferrin, desferrioxaime, or EDTA compared with unsupplemented controls. In a follow-up study, pooled semen samples were randomly collected from toms, diluted with a commercial poultry semen extender supplemented with 5, 10, or 20 mg/mL of 2,2'-dipyridyl and inoculated with an average of 10(8) cfu/mL of a wild-type C. coli turkey semen isolate. At 6 and 24 h of storage at 4 degrees C, samples were taken from each treatment group, enumerated for Campylobacter, and evaluated for sperm viability. In all 3 trials, supplementing the commercial poultry semen extender with 20 mg/mL of 2,2'-dipyryidyl significantly reduced (3 to 4 logs) Campylobacter concentrations when compared with the positive controls. Sperm viability was also reduced with this treatment, and, therefore, the use of 2,2'-dipyridyl may not be a practical treatment for reducing Campylobacter in poultry semen.

Reducing the Carriage of Foodborne Pathogens in Livestock and Poultry

Several foodborne pathogens, including Salmonella species and campylobacters, are common contaminants in poultry and livestock. Typically, these pathogens are carried in the animal's intestinal tract asymptomatically; however, they can be shed in feces in large populations and be transmitted by other vectors from feces to animals, produce, or humans. A wide array of interventions has been developed to reduce the carriage of foodborne pathogens in poultry and livestock, including genetic selection of animals resistant to colonization, treatments to prevent vertical transmission of enteric pathogens, sanitation practices to prevent contamination on the farm and during transportation, elimination of pathogens from feed and water, feed and water additives that create an adverse environment for colonization by the pathogen, and biological treatments that directly or indirectly inactivate the pathogen within the host. To successfully reduce the carriage of foodborne pathogens, it is likely that a combination of intervention strategies will be required.

Effects of Aeration and Storage Temperature on Campylobacter Concentrations in Poultry Semen

Campylobacter is one of the most commonly reported bacterial causes of human foodborne infections in the United States. Recent evidence has demonstrated that Campylobacter is present in poultry semen and may contribute to the vertical transmission between the breeder hen and offspring. As Campylobacter is considered sensitive to oxygen and cold temperature, the objective of this study was to determine if aeration and storage temperature could reduce or eliminate Campylobacter in poultry semen. In 4 separate trials, pooled semen samples were collected from roosters or toms, diluted with a commercial poultry semen extender, and inoculated with an average of 10(7) cells/mL of a wild-type C. jejuni or C. coli semen isolate. Pooled ejaculates were then divided into 3 aeration treatments: Control (no aeration), air, or oxygen (gently bubbled for 20 min with atmospheric air or oxygen, respectively). Immediately after aeration, pooled semen samples were further divided to 3 test storage temperatures: 4, 23, or 42 degrees C. At 0, 2, 6, and 24 h of storage, samples were enumerated for Campylobacter. Aeration of the semen alone, or aeration with reduced temperatures (4 or 23 degrees C), did not reduce the amount of Campylobacter compared with the controls. Campylobacter concentrations were, however, reduced when stored at 42 degrees C for 24 h. This effect is associated with reduced sperm viability and is therefore not a practical treatment of reducing Campylobacter in semen. It appears alternative methods will be needed to eliminate Campylobacter from poultry semen.