Selection and characterization of bacteriophages specific to Salmonella Choleraesuis in swine

Research (Published online: 16-12-2022)

14. Selection and characterization of bacteriophages specific to Salmonella Choleraesuis in swine

Pattaraporn Sriprasong, Napakhwan Imklin, and Rujikan Nasanit

Veterinary World, 15(12): 2856-2869

ABSTRACT

Background and Aim: Salmonella Choleraesuis is the most common serotype that causes salmonellosis in swine. Recently, the use of bacteriophages as a potential biocontrol strategy has increased. Therefore, this study aimed to isolate and characterize bacteriophages specific to S. Choleraesuis associated with swine infection and to evaluate the efficacy of individual phages and a phage cocktail against S. Choleraesuis strains in simulated intestinal fluid (SIF).

Materials and Methods: Three strains of S. Choleraesuis isolated from pig intestines served as host strains for phage isolation. The other 10 Salmonella serovars were also used for the phage host range test. The antibiotic susceptibility of the bacterial strains was investigated. Water samples from natural sources and drain liquid from slaughterhouses were collected for phage isolation. The isolated phages were characterized by determining the efficiency of plating against all Salmonella strains and the stability at a temperature range (4°C–65°C) and at low pH (2.5–4.0) in simulated gastric fluids (SGFs). Furthermore, morphology and genomic restriction analyses were performed for phage classification phages. Finally, S. Choleraesuis reduction in the SIF by the selected individual phages and a phage cocktail was investigated.

Results: The antibiotic susceptibility results revealed that most Salmonella strains were sensitive to all tested drugs. Salmonella Choleraesuis KPS615 was multidrug-resistant, showing resistance to three antibiotics. Nine phages were isolated. Most of them could infect four Salmonella strains. Phages vB_SCh-RP5i3B and vB_SCh-RP61i4 showed high efficiency in infecting S. Choleraesuis and Salmonella Rissen. The phages were stable for 1 h at 4°C–45°C. However, their viability decreased when the temperature increased to 65°C. In addition, most phages remained viable at a low pH (pH 2.5–4.0) for 2 h in SGF. The efficiency of phage treatment against S. Choleraesuis in SIF showed that individual phages and a phage cocktail with three phages effectively reduced S. Choleraesuis in SIF. However, the phage cocktails were more effective than the individual phages.

Conclusion: These results suggest that the newly isolated phages could be promising biocontrol agents against S. Choleraesuis infection in pigs and could be orally administered. However, further in vivo studies should be conducted.

Keywords: antimicrobials, bacteriophage, biocontrol, Salmonella Choleraesuis, swine.

Estimation of the herd-level basic reproduction number for African swine fever in Vietnam, 2019

Research (Published online: 15-12-2022)

13. Estimation of the herd-level basic reproduction number for African swine fever in Vietnam, 2019

Thi Ngan Mai, Thanh Trung Nguyen, Viet Anh Vu, Thi Ngoc Vu and Thi My Le Huynh

Veterinary World, 15(12): 2850-2855

ABSTRACT

Background and Aim: African swine fever (ASF) is a notifiable viral disease of pigs and wild boars that causes severe economic losses to the swine industry. The pig industry in Vietnam was recently attacked by the ASF virus (ASFV) for the first time in history. However, we lack information regarding the transmissibility of ASF within indoor production systems communities, such as those in Vietnam. Therefore, we aimed to estimate the basic reproduction number (R0) for ASF during the early stages of transmission between farms in indoor production system communities from local and national data in Vietnam.

Materials and Methods: The linear regression model approach for the susceptible infectious method was used in this study to estimate the transmission rate and, consequently, the R0 value.

Results: The R0 values between-farm of ASF ranged from 1.41 to 10.8 in different scenarios of infectious period duration, from 15 to 30 days at the national and local levels.

Conclusion: These results help to understand the scale and speed of ASF infection in Vietnam and to provide a scientific basis to implement control measures to restrict the spread of ASFV in other locations.

Keywords: African swine fever, basic reproduction number, indoor production, Vietnam.

Prevalence of Toxoplasma gondii, Leptospira spp., and Coxiella burnetii-associated antibodies in dairy cattle with reproductive disorders

Research (Published online: 15-12-2022)

12. Prevalence of Toxoplasma gondii, Leptospira spp., and Coxiella burnetii-associated antibodies in dairy cattle with reproductive disorders

V. Balamurugan, K. Vinod Kumar, Anusha Alamuri, P. P. Sengupta, G. Govindaraj, and B. R. Shome

Veterinary World, 15(12): 2844-2849

ABSTRACT

Background and Aim: In cattle dairy farms, abortions and other reproductive problems due to major infectious diseases are overlooked, and identifying their causative agents is very challenging without a confirmatory diagnosis. Further, a prevalence study in animals will provide important hints of pathogen reservoirs and provide necessary direction to disease burden with appropriate control and biosecurity measures at the farm level. This study aimed to estimate the prevalence of Toxoplasma gondii antibodies in dairy cattle associated with reproductive problems along with coexisting antibodies against abortifacient zoonotic (Coxiella burnetii and Leptospira spp.) pathogens.

Materials and Methods: Cattle sera (n = 246) from dairy farms (n = 35) situated in different locations in India were screened for anti-T. gondii and C. burnetii antibodies with enzyme-linked immunoassay and Leptospira spp. antibodies with microscopic agglutination test.

Results: The overall prevalence of 11.4% (95% confidence intervals [CIs]: 7.99%–15.96%) antibodies in cattle associated with reproductive problems (p < 0.021) with farm-level seropositivity of 43% was observed. Further, on analysis of screened sera, 49.8% (95% CI: 42.6%–55%) and 77.6% (95% CI: 72%–82.4%) of samples were found to be positive for C. burnetii and Leptospira spp. antibodies, respectively. Moreover, the seropositivity of 91.9% (226/246) for at least one of the screened zoonotic pathogens was observed, indicating antibodies against either of these organisms in association with reproductive disorders (p < 0.005). The percentage of cattle found to have T. gondii antibodies was only 1.8%, whereas 11.5% and 41.6% of cattle were found to have C. burnetii and Leptospira spp. antibodies, respectively. Nevertheless, the predominantly mixed infections observed were of Leptospira and C. burnetii (34.5%), followed by all three infections (4.9%); toxoplasmosis and leptospirosis (3.5%); and toxoplasmosis and Q fever (2.2%).

Conclusion: The serological detection of antibodies against these pathogens in cattle may have significant implications for the livestock industry and public health, suggesting the need for continuous surveillance and monitoring of these infections to prevent their spread.

Keywords: dairy cattle, leptospirosis, Q fever, seroprevalence, toxoplasmosis.

The reversible effects of gossypol toxicity on male pigeons' reproductive performance

Research (Published online: 13-12-2022)

11. The reversible effects of gossypol toxicity on male pigeons' reproductive performance

Suwarak Wannaratana, Wijit Banlunara, Kaj Chokeshaiusaha, and Thanida Sananmuang

Veterinary World, 15(12): 2836-2843

ABSTRACT

Background and Aim: Gossypol, a cotton seed derivative, is well known for its reversible antifertility in male reproduction across species. Its antifertility and reversibility effects on male reproductive function vary among species in dose-and time-dependent manners. In this study, the antifertility potential of gossypol in pigeons was evaluated for the first time to determine whether it might be used as a dietary supplement for pigeon population control.

Materials and Methods: Male pigeons were assigned into three experimental groups: The gossypol-treated group (n = 12), the sham control group (n = 6), and the negative control group (n = 6). There were two experimental periods: A gossypol-feeding period of 28 days and a gossypol-free period of 28 days. During the gossypol-feeding period, birds in the gossypol-treated group were fed 4 mg of gossypol extract per day. Birds in the sham control group were fed 0.5 mL of mixed ethanol and sunflower oil, while those in the negative control group were fed 0.5 mL of phosphate buffer saline. After the gossypol-feeding phase was completed, all remaining pigeons in all groups continued to receive their regular diet for an additional 28 days (gossypol-free phase). The body weight and semen quality of the birds in the experimental groups were compared to evaluate gossypol's antifertility effect.

Results: In the gossypol-treated group as compared to the control groups, the percentages of sperm motility and viability were significantly lower at 21 days, and the percentage of normal sperm morphology was significantly lower at 28 days during the gossypol-feeding period. After gossypol withdrawal, these antifertility effects were resumed and reached a comparable semen quality to the control groups within 14 days.

Conclusion: Gossypol supplementation (4 mg/day for 28 days) could lower male pigeons' reproductive performance in terms of sperm motility, viability, and sperm morphology. Such infertility was, however, reversible within 14 days after gossypol withdrawal without any side effects on the pigeons, suggesting its application as a safe contraceptive feeding for male pigeons.

Keywords: gossypol, pigeon, sperm morphology, sperm motility, sperm viability.

Seroprevalence of nasal myiasis in camels determined by indirect enzyme-linked immunosorbent assay utilizing the most diagnostic Cephalopina titillator larval antigens

Research (Published online: 13-12-2022)

10. Seroprevalence of nasal myiasis in camels determined by indirect enzyme-linked immunosorbent assay utilizing the most diagnostic Cephalopina titillator larval antigens

Noha M. F. Hassan, Doaa Sedky, Nadia M. T. Abu El Ezz, and Eman E. El Shanawany

Veterinary World, 15(12): 2830-2835

ABSTRACT

Background and Aim: Nasal myiasis is a serious parasitic disease among camels caused by Cephalopina titillator larvae that negatively affect animal health and production globally. The diagnosis of the infestation relies on postmortem examination of the head region, which considers a cause impeding treatment of live animals and may be misdiagnosed as central nervous system disorders. This study aimed to identify the most diagnostic larval antigen with the capacity for monitoring C. titillator infestation, and to estimate the seroprevalence of nasal myiasis in camels in Egypt, using indirect enzyme-linked immunosorbent assay (ELISA).

Materials and Methods: Three hundred and six male camels of Egyptian and Sudanese breeds, aged 2–5 years, were clinically evaluated for respiratory and/or nervous disorders in Cairo Governorate, Egypt. At the time of slaughter, blood samples were collected from all examined animals. The postmortem examination of 38 animals was conducted. Salivary glands, hemolymph, and somatic antigens were extracted from the second and third larval instars.

Results: The results revealed that the salivary gland antigen was the most potent antigen in detecting C. titillator specific total IgG antibodies compared to haemolymph and crude somatic antigens. Using receiver-operating characteristic curves and area under the curve, the salivary gland antigen had a sensitivity of 91.67% and a specificity of 92.31%, respectively. It has the highest positive predictive value, 95.7%, and negative predictive value, 85.7%. However, using somatic and hemolymph antigens revealed a sensitivity of 79.17% and 70.83% and a specificity of 76.9% and 84.6%, respectively. There was complete concordance between ELISA results and autopsy findings (true positive). One hundred and forty out of 306 (45.8%) camel serum samples were found to contain C. titillator.

Conclusion: This study demonstrated that salivary gland antigen is more effective than somatic and hemolymph antigens in accurately detecting nasal myiasis in camels. In addition, determining the seroprevalence of nasal myiasis with the salivary gland antigen through indirect ELISA revealed that it is a prevalent disease among camels in Egypt. Periodic surveillance of the C. titillator prevalence is necessary for effective management and control measures.

Review of pork and pork products as a source for transmission of methicillin-resistant Staphylococcus aureus

Review (Published online: 12-12-2022)

8. Review of pork and pork products as a source for transmission of methicillin-resistant Staphylococcus aureus

Aswin Rafif Khairullah, Sri Agus Sudjarwo, Mustofa Helmi Effendi, Sancaka Cashyer Ramandinianto, Maria Aega Gelolodo, Agus Widodo, Katty Hendriana Priscilia Riwu, and Dyah Ayu Kurniawati

International Journal of One Health, 8(2): 167-177

ABSTRACT

Methicillin-resistant Staphylococcus aureus (MRSA) is an opportunistic bacterium that can cause infection in animals and humans. Recently, MRSA from food-producing or farm animals has been identified as livestock-associated MRSA (LA-MRSA). The spread of LA-MRSA is particularly found in pork and pork products because LA-MRSA has been widely known to infect pigs. The most common type of LA-MRSA identified in pork and pork products is the clonal complex LA-MRSA 398 (LA-MRSA CC398). The MRSA strains on the surface of pork carcasses can be spread during the handling and processing of pork and pork products through human hands, cutting tools, and any surface that comes into direct contact with pork. Food infection is the main risk of MRSA in pork and pork products consumed by humans. Antibiotics to treat food infection cases due to MRSA infection include vancomycin and tigecycline. The spread of MRSA in pork and pork products is preventable by appropriately cooking and cooling the pork and pork products at temperatures above 60°C and below 5°C, respectively. It is also necessary to take other preventive measures, such as having a clean meat processing area and disinfecting the equipment used for processing pork and pork products. This review aimed to explain epidemiology, transmission, risk factors, diagnosis, public health consequences, treatment of food poisoning, and preventing the spread of MRSA in pork and pork products.

Keywords: antibiotics, livestock, methicillin-resistant Staphylococcus, pork products.

Multidrug resistance-encoding gene in Citrobacter freundii isolated from healthy laying chicken in Blitar District, Indonesia

Research (Published online: 12-12-2022)

7. Multidrug resistance-encoding gene in Citrobacter freundii isolated from healthy laying chicken in Blitar District, Indonesia

Adiana Mutamsari Witaningrum, Freshinta Jellia Wibisono, Dian Ayu Permatasari, Mustofa Helmi Effendi, and Emmanuel Nnabuike Ugbo

International Journal of One Health, 8(2): 161-166

ABSTRACT

Background and Aim: The increasing prevalence of resistance (MDR) of Enterobacteriaceae in Indonesia has caused concern regarding human health. Citrobacter freundii reportedly targets the gastrointestinal tract of animals and is a common cause of foodborne diseases associated with diarrhea, peritonitis, meningitis, brain abscess, bacteremia, and urinary tract infection. This study aimed to estimate the prevalence of MDR and the presence of Class 1 integron-encoding genes in C. freundii isolates obtained from cloacal swabs of healthy laying chickens in Blitar district, Indonesia.

Materials and Methods: One hundred and sixty-five cloacal swab samples were collected from 33 farms in Blitar over a period of 4 months. Standard microbiological techniques such as bacterial culture in MacConkey agar, Simmons citrate agar, and triple sugar iron agar and biochemical tests such as the indole test were performed to identify the isolates. The antibiotic sensitivity patterns of C. freundii isolates were determined by the disk diffusion method, and MDR-encoding genes (Class 1 integron) were detected by polymerase chain reaction (PCR).

Results: Out of 165 cloacal swab samples, 7 (4.24%) were positive for C. freundii. Citrobacter freundii was highly resistant to erythromycin (71.43%) and moderately to streptomycin, tetracycline, and trimethoprim-sulfamethoxazole (all 42.86%); however, it showed low resistance to ampicillin (28.57%). All isolates were found to exhibit MDR. Only 1 (14.29%) of the seven C. freundii isolates harbored a Class 1 integron gene. This study revealed that Class 1 integron-encoding genes have a low prevalence in C. freundii isolated from healthy laying chickens in Blitar, Indonesia.

Conclusion: Poultry animals can play a role in the transmission of resistance genes to humans due to the MDR of Enterobacteriaceae, including C. freundii in the intestines.

Keywords: Citrobacter freundii, Class 1 integron gene, human health, laying chickens, multidrug resistance.