Detection of invA gene of Salmonella from milkfish (Chanos chanos) at Sidoarjo wet fish market, Indonesia, using polymerase chain reaction technique

Research (Published online: 29-01-2019)

25. Detection of invA gene of Salmonella from milkfish (Chanos chanos) at Sidoarjo wet fish market, Indonesia, using polymerase chain reaction technique

Sheila Marty Yanestria, Reina Puspita Rahmaniar, Freshinta Jellia Wibisono and Mustofa Helmi Effendi

Veterinary World, 12(1): 170-175

ABSTRACT

Aim: The study aimed to detect the invA gene in Salmonella isolated from milkfish in the Sidoarjo wet fish market.

Materials and Methods: A total of 84 samples were prepared in enrichment media and isolated on the surface of Salmonella Shigella Agar. Salmonella growth produces transparent colonies with blackish color in the middle due to H2S gas formation. Samples were identified as Salmonella based on macroscopic colony morphology. Presumptive Salmonella sp. was put on Bismuth Sulfite Agar media. Salmonella was determined based on the results of the biochemical test that has been carried out using Microbact identification kits from negative gram staining.

Results: The results of this study indicate that 32 of 84 samples (38.09%) were Salmonella bacteria. Furthermore, the invA gene detection was carried out using the polymerase chain reaction technique. Electrophoresis results showed four positive samples contained invA gene with a length of 284 bp.

Conclusion: Results in this study indicate that contamination of milkfish with Salmonella needs strict hygienic measures to prevent their transmission to human.

Keywords: human health, invA gene, milkfish, polymerase chain reaction, Salmonella.

Contamination of Streptococcus suis in pork and edible pig organs in central Thailand

Research (Published online: 29-01-2019)

24. Contamination of Streptococcus suis in pork and edible pig organs in central Thailand

Nuchjaree Boonyong, Sarawan Kaewmongkol, Duangdaow Khunbutsri, Khomsan Satchasataporn and Nattakan Meekhanon

Veterinary World, 12(1): 165-169

ABSTRACT

Background and Aim: Streptococcus suis is an important zoonotic pathogen that can cause serious diseases in both swine and humans worldwide, especially in Asian countries. Since the majority of human cases reported in Thailand were infected by the consumption of a raw pork dish, the microbial food safety hazard associated with raw meat has been a matter of concern. Therefore, this study aimed to investigate the contamination by S. suis in pork and edible pig organs sold in central Thailand.

Materials and Methods: In total, 88 raw pork and pig organ samples were purchased from markets, butcher shops, and supermarkets in central Thailand. The samples were examined using the loop-mediated isothermal amplification (LAMP) technique. LAMP reactions used for the detection of the DNA of S. suis (LAMPSS) and S. suis serotype 2 or 1/2 (LAMPSS2) were carried out according to previous studies.

Results: The percentage of LAMPSS-positive samples was as high as 85.23% (75/88) while the percentage of LAMPSS2- positive samples was 17.05% (15/88). The percentages of LAMPSS- and LAMPSS2-positive samples were relatively high in both pig organs (lung and heart) and meat (sliced pork and minced pork) compared with the previous report. Except one supermarket, LAMPSS-positive samples were found in all sources investigated in this study. The pork and pig organs obtained from the markets and the butcher shops additionally gave positive results for LAMPSS2.

Conclusion: Using LAMP techniques, high rate contamination of S. suis was found in raw pork and edible pig organs sold at different sources in central Thailand. The cross-contamination could have occurred through slaughtering, meat cutting, and meat handling processes. Therefore, consumers and people involved in the pig production industry should be aware of the potential hazards of S. suis infection; food safety education is crucial to prevent further infection.

Keywords: contamination, loop-mediated isothermal amplification, pork, Streptococcus suis, Thailand.

Combined impacts of oregano extract and vacuum packaging on the quality changes of frigate tuna muscles stored at 3±1°C

Research (Published online: 28-01-2019)

23. Combined impacts of oregano extract and vacuum packaging on the quality changes of frigate tuna muscles stored at 3±1°C

Talal Lahreche, Yilmaz Ucar, Ali Riza Kosker, Taha-Mossadak Hamdi and Fatih Ozogul

Veterinary World, 12(1): 155-164

ABSTRACT

Aim: The combined effects of oregano extract with vacuum packing (VP) on the quality enhancement of dark and white muscles of frigate tuna (Auxis thazard) stored as intact fillet at refrigerated (3±1°C) conditions were studied.

Materials and Methods: About 35 kg of fish were filleted without skin removal and randomly divided into two groups. One group without treatment (control) and the remaining group were dipped in a sterilized oregano extract solution for 5 min. Chemical, microbiological, sensorial, and textural analyses were carried out in each of dark and white muscles of frigate tuna fillets during storage.

Results: Several quality indexes were higher in dark muscle than white muscle. The sensory assessment indicated that both muscles from control had a shelf life of 12 days. Quality parameters of both muscles had the same tendency and were significantly affected by time and also by the presence of plant extract in VP. Although VP alone was sufficient to delay lipid oxidation on fish fillets, especially on dark muscle but cannot enhance the textural deterioration in both muscles.

Conclusion: Consequently, the employment of such combination had a cumulative effect on preservation, resulting in prolonging the shelf life of both frigate tuna muscles.

Keywords: dipping, fish muscles, oregano extract, quality parameters, refrigerated storage, vacuum packaging.

Random amplified polymorphic DNA-based molecular heterogeneity analysis of Salmonella entericaisolates from foods of animal origin

Research (Published online: 26-01-2019)

22. Random amplified polymorphic DNA-based molecular heterogeneity analysis of Salmonella entericaisolates from foods of animal origin

Surendra Singh Shekhawat, Abhishek Gaurav, Bincy Joseph, Hitesh Kumar and Nirmal Kumar

Veterinary World, 12(1): 146-154

ABSTRACT

Aim: This study aims to study the significance of random amplified polymorphic DNA (RAPD) typing in heterogeneity analysis of Salmonella serovars, isolated from foods of animal origin.

Materials and Methods: Salmonella serovars isolated and identified from different foods of animal origin such as meat, milk, and egg by standard bacteriological methods. DNA isolated from all 10 isolates which are confirmed by biochemical and serotyping methods and then RAPD was performed using the primers OPB 10, primer 1290, NSC I, NSC II, and primer 3. Then, RAPD data were analyzed using the BioNumerics software, Belgium, Germany.

Results: RAPD polymerase chain reaction (PCR) using five primers, namely OPB 10, primer 1290, NSC I, NSC II, and primer 3, classified the 10 isolates into 9, 10, 10, 7, and 10 RAPD-PCR types with discriminating powers of 0.1987, 0.423, 0.50889, 0.1842, and 0.2582, respectively. The phylogram constructed with NSC I profile classified isolates based on geographical origin. Primer 1290, NSC II, and primer 3 produced some uniform bands in all isolates indicating their binding ability in conserved genomic region. This study revealed that RAPD profile can be best used for finding out the heterogeneity at molecular level of Salmonella isolates in combination with other molecular and phenotypic typing techniques. Thus, our results support earlier observation of its significance by different workers on different Salmonella serotypes.

Conclusion: Repeatability of RAPD-PCR is insufficient to distinguish genetic differences among Salmonella serovars.

Keywords: Salmonella, random amplified polymorphic DNA, foods of animal origin, phylogram.

The occurrence of disinfectant and antibiotic-resistant genes in Escherichia coli isolated from chickens in Egypt

Research (Published online: 25-01-2019)

21. The occurrence of disinfectant and antibiotic-resistant genes in Escherichia coli isolated from chickens in Egypt

Waleed A. Ibrahim, Sherif A. Marouf, Ahmed M. Erfan, Soad A. Nasef and Jakeen K. El Jakee

Veterinary World, 12(1): 141-145

ABSTRACT

Aim: This work aimed to determine the occurrence of antibiotic and disinfectant resistance genes in Escherichia coli isolated from chickens in Egypt.

Materials and Methods: Organs (liver, lung, heart, yolk sac, and bone marrow) of 1500 chicken samples were collected from diseased chickens suffered from colibacillosis with PM findings as CRD, diarrhea and omphalitis from different governorates of Egypt as: Giza, EL-Bahira, Fayoum, El-Dakahlia, El-Ismalia, and El-Sharkia during 2015-2016. These samples were labeled and transported immediately on ice to the Reference laboratory for quality control on poultry production (RLQP). The samples were cultured onto MacConkey agar and Eosin Methylene Blue Agar. Isolation and identification of the E. coli were performed based on morphology, cultural, staining, and biochemical properties. Antimicrobial resistance test was carried out using disk diffusion method. The PCR employing tetA, qacED1 and qacA/B were carried out for detection of these genes in isolated E.coli.

Results: The prevalence of E. coli in chicken was 34%. Predominant serotypes of E. coli which serologically identified were O128, O111, O44, O158, and O2. Antibiotic susceptibility test of E. coli revealed that 100% of isolates were resistant to ampicillin, erythromycin, and sulfamethoxazole-trimethoprim, while 73.53% and 38.23% of them were sensitive for colistin sulfate and levofloxacin, respectively. Antibiotic resistance genes as tetA gene were tested for isolated E. coli and detected by incidence rate of 91.18%. qac resistance genes resembling as qacED1 and qacA/B genes were detected in isolated E. coli 70.6% and 14.7%, respectively.

Conclusion: E. coli isolated from chickens in Egypt was carried qac and antibiotic-resistant genes that affect the poultry industry.

Keywords: antimicrobial resistance, chickens, Egypt, Escherichia coli, qac resistance genes.

Features of formation of Yersinia enterocolitica biofilms

Research (Published online: 25-01-2019)

20. Features of formation of Yersinia enterocolitica biofilms

E. Lenchenko, D. Lozovoy, A. Strizhakov, Yu Vatnikov, V. Byakhova, Eu Kulikov, N. Sturov, V. Kuznetsov, V. Avdotin and V. Grishin

Veterinary World, 12(1): 136-140

ABSTRACT

Aim: The work aimed to study the morphology of colonies and their comparison by features of the formation of Yersinia enterocolitica biofilms.

Materials and Methods: Bacteria were cultured on a Yersinia Selective Agar medium ("CIN-agar") at 28°C for 24 h. The microorganisms were grown in meat-peptone broth with 1.0% glucose to measure the absolute values of the optical density of the culture. The optical density of the liquid was determined in a microplate photometric analyzer Immunochem-2100 (HTI, USA) at a wavelength of 490 nm. For the study of biofilms, the specimens were fixed for 3-5 h in pairs of 25.0% solution of glutaraldehyde (according to DV), and pairs of a 1.0% aqueous solution of osmic acid (OSO4) were used for contrasting for 2-3 min. The specimens were examined with stereoscopic microscopy "BIOMED MS-1 Stereo" (Russia) and scanning electron microscope "TM 3030 plus" (Holland).

Results: With stereoscopic microscopy of the colonies of Y. enterocolitica, the S-forms had an elevated intensely colored center, radial striation along the periphery, smooth edges, d ≤ 1.0 mm. R-form colonies had a dark color and a dry surface, were tuberous and had a dense center with a peripheral ridge, rugged edges, d ≥ 1.5 mm. The optical density of the Y. enterocolitica S-form showed that this type of microorganism belongs to the moderate producers of biofilms since the optical density of the sample (density of the sample - Ds) exceeded the optical density of control (density of the control - Dc) by 3 times. In Y. enterocolitica R-form (D ≤ 0.197) weakly produced biofilms, the optical density of the sample exceeded the optical density of the control by <2 times.

Conclusion: The ability to form biofilms, the variability of phenotypic features, and the multiplicity of virulence factors of bacteria significantly reduce the effectiveness of diagnostic studies. The development of accelerated methods of detection and differentiation of the virulent properties of pathogenic bacteria will allow scientifically to substantiate and develop a set of measures aimed at preventing animal diseases and obtaining safe livestock products to prevent human diseases. Thus, we need to pay attention to which forms of colonies do Y. enterocolitica form on solid nutrient media: S- or R-forms. Through this study, we know that bacteria-forming S-shaped colonies are more capable of forming biofilms than R-forms. It means that they are more pathogenic and can cause persistent infections due to adhesion and biofilm formation.

Keywords: adhesion, biofilms, clusters, electron microscopy, heteromorphism, matrix, optical microscopy, stereoscopic microscopy, Yersinia.

Molecular evidence of Ehrlichia canis and Anaplasma platys and the association of infections with hematological responses in naturally infected dogs in Kalasin, Thailand

Research (Published online: 23-01-2019)

19. Molecular evidence of Ehrlichia canis and Anaplasma platys and the association of infections with hematological responses in naturally infected dogs in Kalasin, Thailand

Supawadee Piratae, Priyakorn Senawong, Pornchalerm Chalermchat, Warissara Harnarsa and Benjawan Sae-chue

Veterinary World, 12(1): 131-135

ABSTRACT

Background: Tick-borne bacteria, Anaplasma platys and Ehrlichia canis are well recognized as the etiology of anemia and thrombocytopenia in dogs. The clinical signs of anaplasmosis and ehrlichiosis range from asymptomatic to severe symptoms. There are insufficient studies about epidemiological surveys of these blood parasites, also the association of infections with the hematological study.

Aim: This study aimed to screen A. platys and E. canis in naturally infected dogs and the effects of the infection on the levels of packed cell volume (PCV) and platelet count.

Materials and Methods: A total of 68 blood samples were collected from free-roaming dogs at Nong Kung Sri district, Kalasin Province, Thailand, and examined for A. platys and E. canis infection by polymerase chain reaction (PCR) and measured PCV levels and platelet count.

Results: Using nested PCR, 42.65% of dogs were infected with one or two pathogens. The molecular detection of anaplasmosis and ehrlichiosis in this population was 29.4% (95% confidence interval [CI]: 18.98-41.71) and 25% (95% CI: 14.4-35.3), respectively. Coinfection occurred at 11.8% (95% CI: 5.22-21.87). Infection with E. canis and coinfection showed significant association with PCV levels (p<0.05) while A. platys infection showed no statistical relationship. Infection with A. platys, E. canis, and coinfection had a non-significant correlation with platelet count (p>0.05).

Conclusion: This study provides data of anaplasmosis and ehrlichiosis in free-roaming dogs which indicated that these zoonotic diseases are widespread and require for disease frequency determination, especially in Kalasin Province of Thailand where data of tick-borne infections in dogs have not been reported.

Keywords: packed cell volume, platelet count, Thailand, tick-borne pathogens.