Bacteriological and molecular study of Salmonella species associated with central nervous system manifestation in chicken flocks

Research (Published online: 20-10-2020)

20. Bacteriological and molecular study of Salmonella species associated with central nervous system manifestation in chicken flocks

Heba Badr, Mohamed A. Soliman and Soad A. Nasef

Veterinary World, 13(10): 2183-2190

ABSTRACT

Background and Aim: Salmonella species often cause systemic health problems in poultry flocks, sometimes including nervous systems manifestations. This impact of Salmonella has rarely been studied. This study aimed to define an alternative pathogenic pathway for Salmonella spp. invasion of brain tissue in chicken flocks. Brain infection produces neurological manifestations; Salmonella strains isolated from brain tissue showed the presences of two virulence genes. Confirmation of the pathway of isolates from intestinal mucosa through the blood–brain barrier was attained using experimental infections in specific pathogen-free (SPF)-day-old chicks through two routes of inoculation.

Materials and Methods: Isolation of Salmonella spp. from five chicken flocks that showed signs of the central nervous system (CNS) effects were isolated. Isolates were characterized by serotyping, and antimicrobial assays. In addition, virulence profiles were described using detection of virulence plasmid spvC, and Salmonella plasmid sopB. A pathogenicity study of isolates in specific pathogen-free (SPF)-day-old chicks through oral and intracerebral administration performed, and experimental infection in SPF embryonated chicken eggs through intra-yolk and intra-allantoic administration was investigated. Supporting histopathology and immunohistopathology against Salmonella antigen in brain tissue were performed for flock and experimental infections.

Results: Three serotypes of Salmonella were isolated from the brains of five flocks (two Salmonella Virchow, two Salmonella Kentucky, and one Salmonella Enteritidis isolates). Phage related gene sopB and plasmid-mediated operon spvC were identified in all isolated strains. The Salmonella strains were re-isolated and identified from the brain and internal organs of post-experimental infected chicks. Infected chicks showed nervous manifestations associated with Salmonella infection. The presence of positively stained Salmonella antigen in brain tissues indicates penetration of the blood–brain barrier by the Salmonella species.

Conclusion: Our results indicate that some virulent systemic strains of Salmonella spp. can induce CNS manifestations in chicken hosts.

Keywords: chicken, experimental study, CNS manifestations, polymerase chain reaction, Salmonella spp., virulence genes.

Antileishmanial and cytotoxic activities of four Andean plant extracts from Colombia

Research (Published online: 19-10-2020)

19. Antileishmanial and cytotoxic activities of four Andean plant extracts from Colombia

Wilson Cardona-G, Sara Robledo, Fernando Alzate, Andrés F. Yepes, Cristian Hernandez, Ivan Dario Velez, Juan Carlos Calderon and Isabel Vásquez Tabares

Veterinary World, 13(10): 2178-2182

ABSTRACT

Background and Aim: Licania salicifolia (L.S) Cuatrec., Persea ferruginea (P.F) Kunth, Oreopanax floribundus (O.F), and Psychotria buchtienii (P.B) belong to the families Chrysobalanaceae, Lauraceae, Araliaceae, and Rubiaceae, respectively, which have been used as medicines by communities in the Andes. This study evaluated the leishmanicidal and cytotoxic activities of alcohol and non-alcohol extracts from four Andean plant extracts (L.S, O.F, P.F, and P.B).

Materials and Methods: Extracts were obtained by percolation with solvents of different polarities – hexane, dichloromethane, ethyl acetate, and ethanol. Phytochemical screening was conducted based on reported methods. All products were evaluated in vitro to determine the leishmanicidal activity against amastigotes of Leishmania panamensis and cytotoxicity against U937 cells.

Results: Flavonoids, triterpenes, and tannins were the main secondary metabolites found. From the results, dichloromethane extracts from O.F and P.B, ethanol extract from P.B, and ethyl acetate extracts of all plants were active, with EC50 <30 μg/mL. Ethyl acetate was the most active extract, which showed EC50 values of 9.8, 14.1, 23.7, and 25.5 μg/mL, for L.S, P.B, O.F, and P.F, respectively. Hexane extracts from P.B and O.F exhibited moderate activity with EC50 values of 84.8 and 87.4 μg/mL, respectively. Hexane and ethanol extracts from O.F, ethyl acetate, and ethanol extracts from L.S, and all extracts from P.F were not toxic. Alternatively, hexane and dichloromethane extracts from L.S and P.B as well as dichloromethane and ethyl acetate extracts from O.F displayed high toxicity.

Conclusion: Based on the activity we observed, ethyl acetate extract can continue in its usage in the search for new antileishmanial drugs, mainly ethyl acetate extract from L.S showed activity comparable to meglumine antimoniate and was not cytotoxic.

Keywords: Araliaceae, Chrysobalanaceae, Lauraceae, Rubiaceae, Leishmaniasis, Licania salicifolia, Oreopanax floribundus, Persea ferruginea, Psychotria buchtienii.

Risk factors associated with stillbirth of piglets born from oxytocin-assisted parturitions

Research (Published online: 17-10-2020)

18. Risk factors associated with stillbirth of piglets born from oxytocin-assisted parturitions

Nguyen Hoai Nam and Peerapol Sukon

Veterinary World, 13(10): 2172-2177

ABSTRACT

Aim: The present study aimed to investigate the effects of different risk factors on stillbirth of piglets born from oxytocin-assisted parturitions.

Materials and Methods: Data were collected from a total of 1121 piglets born from 74 Landrace x Yorkshire crossbred sows from a herd. Logistic regression models were used to determine the associations between stillbirth and different risk factors including parity (1, 2, 3-5, and 6-10), gestation length (GL) (112-113, 114-116, and 117-119 days), litter size, birth order (BO), sex, birth interval (BI), cumulative farrowing duration, birth weight (BW), crown rump length, BW deviation, body mass index, ponderal index (PI), and the use of oxytocin during expulsive stage of farrowing.

Results: The incidence of stillbirth at litter level and stillbirth rate was 59.5% (44/74) and 8.1% (89/1094), respectively. The final multivariate logistic regression selected BO, BI, PI, GL, and parity as the five most significant risk factors for stillbirth. Increased BO and BI, GL <114 and >116 days, parity 6-10, and low PI increased the stillbirth rate in piglets.

Conclusion: Several factors previously determined as risks for stillbirth in exogenous oxytocin-free parturitions also existed in exogenous oxytocin-assisted parturitions. One dose of oxytocin at fairly high BO did not increase stillbirth, whereas two doses of oxytocin were potentially associated with increased values.

Keywords: birth order, oxytocin, pig, ponderal index, stillbirth.

Antibiotic susceptibility and pathogenicity of Aeromonas hydrophila isolated from red hybrid tilapia (Oreochromis niloticus×Oreochromis mossambicus) in Malaysia

Research (Published online: 16-10-2020)

17. Antibiotic susceptibility and pathogenicity of Aeromonas hydrophila isolated from red hybrid tilapia (Oreochromis niloticus×Oreochromis mossambicus) in Malaysia

Nurfarahin Ahmad Pauzi, Nurliyana Mohamad, Mohamad Azzam-Sayuti, Ina Salwany Md. Yasin, Mohd Zamri Saad, Nurrul Shaqinah Nasruddin and Mohammad Noor Amal Azmai

Veterinary World, 13(10): 2166-2171

ABSTRACT

Background and Aim: Aeromonas hydrophila is a major cause of bacterial infections affecting a wide range of warm water fishes worldwide. In Malaysia, A. hydrophila isolations from diseased fishes were previously reported; however, with limited information. The present study investigates the antibiotic susceptibility and pathogenicity of A. hydrophila isolated from farmed red hybrid tilapia (Oreochromis spp.) in Malaysia.

Materials and Methods: A. hydrophila was biochemically identified and subjected to antibiotic susceptibility tests. The isolate was then intraperitoneally injected into red hybrid tilapia, and the mortality, clinicopathological changes, and LD50 were determined up to 240 h post-infection (hpi).

Results: The isolate demonstrated multiple antibiotic resistances (MAR) toward amikacin, ampicillin, cefotaxime, amoxicillin, trimethoprim-sulfamethoxazole, erythromycin, and streptomycin, with a MAR index of 0.5. The experimental infection of A. hydrophila at 105 CFU/mL in the red hybrid tilapia resulted in 100% mortality at 240 hpi. The LD50 was determined at 1.1×104 CFU/mL. Infected fish demonstrated occasional erratic swimming patterns, localized hemorrhages and depigmentation on the body and operculum areas, fin erosion, enlargement of the gall bladder, and hemorrhage in internal organs. Microscopic observation of infected fish revealed brain congestion, tubular necrosis, and glomerular shrinkage in the kidneys, necrosis of hepatocytes, and congestion of blood vessels in the liver.

Conclusion: The high virulence of A. hydrophila to the red hybrid tilapia emphasizes the importance of active, on-going monitoring of its prevalence in Malaysian tilapia farming.

Keywords: Aeromonas hydrophila, antibiotic sensitivity, aquaculture, pathogenicity, tilapia.

Multidrug-resistant Escherichia coli and Salmonella spp. isolated from pigeons

Research (Published online: 15-10-2020)

16. Multidrug-resistant Escherichia coli and Salmonella spp. isolated from pigeons

Shah Jungy Ibna Karim, Mahfuzul Islam, Tahmina Sikder, Rubaya Rubaya, Joyanta Halder and Jahangir Alam

Veterinary World, 13(10): 2156-2165

ABSTRACT

Background and Aim: Pigeon rearing has been gaining popularity for recent years. They are reared remarkably very close to the house of the owner. This activity, therefore, may pose potential threats for humans as well as other animals as pigeons may carry and spread different pathogens including drug-resistant bacteria. This study was conducted to explore the prevalence of Escherichia coli and Salmonella spp. as well as their antibiogram profile along with an association analysis.

Materials and Methods: Forty swab samples were collected from 20 pigeons during the study. E. coli and Salmonella spp. were isolated and identified on various types of agars, including MacConkey, Eosin methylene blue, Brilliant green, and Salmonella-Shigella agar. Biochemical tests such as the carbohydrate fermentation test, the triple sugar iron agar slant reaction, the indole test, the methyl red test, the catalase test, as well as the Voges–Proskauer test were also performed. Besides, the presence of E. coli was further confirmed by polymerase chain reaction (PCR). Moreover, antimicrobial susceptibility testing of the isolates was performed against nine antibiotics from seven classes on the Mueller-Hinton agar based on the Kirby–Bauer disk diffusion method.

Results: The overall prevalence of E. coli and Salmonella spp. was 52.5 and 27.5%, respectively. The prevalence of the pathogenic E. coli was 61.90%. The antibiogram profile of 21 E. coli as well as 11 Salmonella spp. revealed that all isolates, except one, were resistant to one to six antibiotics. Around 61.90%, 71.43%, 23.81%, 61.90%, 23.81%, 19.05%, and 52.38% of E. coli showed resistance against amoxicillin, ampicillin, azithromycin, erythromycin, nalidixic acid, gentamicin, and tetracycline, respectively. Furthermore, E. coli resistance was not observed in case of ciprofloxacin and levofloxacin. Similarly, around 36.36%, 27.27%, 27.27%, 45.45%, 81.82%, 100%, and 18.18% of the Salmonella spp. showed resistance against amoxicillin, ampicillin, azithromycin, erythromycin, nalidixic acid, tetracycline, and levofloxacin, respectively. However, all Salmonella spp. (100%) were found to show sensitivity against ciprofloxacin and gentamicin. Multidrug-resistant (MDR) E. coli (23.80%) and Salmonella spp. (54.54%) were also isolated. Furthermore, both positive (odds ratio [OR] >1) and negative (OR <1) drug resistance associations, with a higher frequency of positive associations, were found in E. coli. A significant positive association was observed between ampicillin and amoxicillin (OR: 81.67, 95% confidence interval: 2.73-2447.57, p=0.01).

Conclusion: Pigeon carrying MDR E. coli and Salmonella spp. may contribute to the transmission and spread of these microorganisms. Therefore, strict hygienic measures should be taken during the farming of pigeons to decrease the potential transmission of E. coli and Salmonella spp. from pigeon to humans as well as other animals. So far, this is the first report of the PCR-based identification of pathogenic E. coli from pigeons in Bangladesh.

Keywords: antimicrobial resistance, Escherichia coli, multidrug resistance, pigeon, Salmonella spp.

Multidrug-resistant strains of Mycobacterium complex species in Egyptian farm animals, veterinarians, and farm and abattoir workers

Research (Published online: 14-10-2020)

15. Multidrug-resistant strains of Mycobacterium complex species in Egyptian farm animals, veterinarians, and farm and abattoir workers

Hossam A. Abdelsadek, Hassan M. Sobhy, Kh. F. Mohamed, Sahar H. A. Hekal, Amany N. Dapgh and Ashraf S. Hakim

Veterinary World, 13(10): 2150-2155

ABSTRACT

Background and Aim: Mycobacterium tuberculosis complex (MTBC) is a group of mycobacteria that are important human pathogens. Mycobacterium tuberculosis and Mycobacterium bovis cause serious chronic life-threatening disease and also significant economic losses in both production and remedication. Recently, emergence of multidrug-resistant tuberculosis (MDR-TB) complex has generated global recognition of the need for rapid and sensitive diagnosis and development of new treatments. The current study illustrates the isolation/identification of MTBC strains in specimens obtained from cows and humans by conventional and real-time polymerase chain reaction (RT-PCR) techniques. Further, the study assesses sensitivity to antituberculosis drugs in isolated MDR strains.

Materials and Methods: A total of 1464 samples from cattle (1285 raw milk and 179 lymph node), and 149 human sputum samples, were collected from farms and abattoirs in Delta Egypt. Conventional methods (culture and Ziehl–Neelsen staining) were implemented as were RT-PCR using MTBC universal DNA. The effect of some antituberculosis drugs on obtained isolates was assayed using drug susceptibility proportion and qualitative suspension techniques.

Results: The MBTC detection rate using the culture method was higher than for Ziehl–Neelsen staining; raw cow milk (2.56 vs. 1.63%), lymph nodes (51.59 vs. 48.04%), and human sputum (5.36 vs. 4.02%). A total of 135 isolates were obtained. Application of RT-PCR detected 138 isolates from the same set of samples. MBTC isolates were resistant to first-line antituberculosis drugs, such as pyrazinamide, isoniazid, rifampicin, and ethambutol by 78.5, 59.3, 40.7, and 31.8%, respectively, and could be highly resistant to kanamycin (82.3%) and amikacin (80.7%). However, isolates remained sensitive to ciprofloxacin (71.1%) and clarithromycin (73.3%) as second-line drugs.

Conclusion: There is a growing risk for isolation of MDR-TB from raw milk and lymph nodes of field tuberculin positive cattle as well as sputum of veterinarians and workers existed in farms and abattoirs. PCR-based techniques have become the gold standard for the identification of mycobacterial species, showing high efficiency compared to bacteriological and microscopic examination. Application of the first- and second-line antituberculosis drugs in combination could counter the MDR-TB concern once infections are identified.

Keywords: antituberculous drugs, Delta Egypt, multidrug-resistant tuberculosis, Mycobacterium tuberculosis complex.

Morphological study of larynx, trachea, and lungs of Didelphis marsupialis (LINNAEUS, 1758)

Research (Published online: 13-10-2020)

14. Morphological study of larynx, trachea, and lungs of Didelphis marsupialis (LINNAEUS, 1758)

Bruna Tassia Santos Pantoja, Armando Reinaldo Marques Silva, Renata Mondego-Oliveira, Thamires Santos Silva, Babara Carvalho Marques, Rafaela Pontes Albuquerque, Joicy Cortez Sá Sousa, Rose Eli Grassi Rici, Maria Angélica Miglino, Alana Lislea Sousa, André Luís Resende Franciolli, Eduardo Martins Sousa, Ana Lúcia Abreu-Silva and Rafael Cardoso Carvalho

Veterinary World, 13(10): 2142-2149

ABSTRACT

Background and Aim: From a biomedical point of view, the value of marsupials as a model of primitive mammals is indisputable. Among its species, the possum is a model that allows the study of the ontogeny of different organic systems, as well as their physiological aspects. The relevance of anatomical, functional, evolutionary, and phylogenetic study of marsupials for the development of comparative morphology is extensively documented in the literature. However, there are still many aspects to be further evaluated, as the anatomy and histology of the respiratory tract of this species. The aim of this study was to describe the morphology of the larynx, trachea, and lungs of Didelphis marsupialis.

Materials and Methods: Five adult male animals were donated to the Comparative Animal Anatomy Laboratory – LAAC/ CCAA-UFMA, for morphological studies. Specimens were washed in running water to perform biometrics. Then, they were fixed with 10% formaldehyde solution. After the fixation period, the specimens were positioned in dorsal decubitus position, for dissection of the respiratory system organs, by opening the ventral region of the neck and thoracic cavity, with subsequent removal of the pectoral muscles, ribs, and sternum. For histological analysis, fragments of 1 cm2 of the larynx (epiglottis and thyroid cartilages), trachea, and lungs were collected and fixed in 10% formaldehyde solution. Right after fixation, the fragments were dehydrated in increasing concentrations of ethyl alcohol (70, 80, 95, and 100%), diaphanized in xylene, embedded in paraffin, and sectioned into thin slices of 5 μm using a microtome. Sections were stained using the hematoxylin and eosin technique.

Results: Anatomically, the larynx starts right after the pharynx. It consisted of four cartilages: Epiglottis, cricoid, thyroid, and arytenoid. The trachea was made of dorsally incomplete cartilaginous rings. At the entrance of the thoracic cavity, it bifurcated into the left and right main bronchus. The left lung was smaller than the right lung, with two lobes (cranial and caudal). The right lung presents the cranial, middle, caudal, and accessory lobes. Histologically, the epiglottis consisted of elastic cartilage and is covered by a non-keratinized stratified squamous epithelium. Thyroid cartilage is made of hyaline cartilage covered by smooth muscle. The trachea presents hyaline cartilage, with ciliated pseudo-stratified epithelium, serous glands, isogenic groups of chondrocytes, and perichondrium. The lung consisted of bronchi, bronchioles, and alveoli, also presenting blood vessels and arteries.

Conclusion: Morphologically, the larynx, trachea, and lungs of D. marsupialis were similar to those of the other Didelphids described in the literature.

Keywords: anatomy, histology, marsupials, respiratory tract.