Assessing hygiene indicators in two dairies in Algeria in producing pasteurized milk

Research (Published online: 04-09-2021)

4. Assessing hygiene indicators in two dairies in Algeria in producing pasteurized milk

Regguem Souad, Hamdi Taha Mossadak and Bouayad Leila

Veterinary World, 14(9): 2317-2324

ABSTRACT

Background and Aim: There is a worldwide controversy about the choice of microbial flora for use as process hygiene indicators. This study aimed to evaluate the pertinence of using either coliforms or Enterobacteriaceae (EB) as process hygiene indicators in the pasteurized milk production line. Two flora families and total flora were used as bacterial indicators in some stages of pasteurized milk production line to identify the origin of post-pasteurization contamination and compare the results obtained for each flora. In addition, the bacteriological profile of isolated coliforms and EB was developed.

Materials and Methods: One thousand and two hundred samples of pasteurized cow milk and surfaces (pipes and tank) at various processing stages were taken from two dairies in the northern region of Algeria. The total microbial flora (TF), total coliforms (TC), thermotolerant coliforms, and EB were enumerated, following the recommendations of ISO 4833:2006, ISO 4832:2006, and ISO 21528-2:2017 methods, respectively. The bacteriological profile was determined using the API 20E and 10S tests (bioMérieux, France). Furthermore, the cleaning efficiency and disinfection protocol of surfaces were evaluated using contact agar slides 1 (Liofilchem™, Italy).

Results: Enumeration of the different indicators shows that the highest contamination rate is recorded by the total flora in the two units, 3.28 and 3.78 log CFU/mL, respectively. EB (–0.60 log CFU/mL) at post-pasteurization stage in Unit 1 and coliforms (0.44 log CFU/mL) at the pasteurized packaged milk stage in Unit 2 are the least significant germ families. The lowest compliance rates of bacterial contamination were reported for total flora (82-85%) at the three sampled sites in Unit 2. In comparison, the highest was reported in Unit 1 (99.8%) and 2 (98%) by the EB indicator. Assessing the surface cleaning and disinfection protocol compliance shows that the tank records the highest non-compliance rates for EB and TF (4% and 3%) in Unit 2. EB are represented in both units by various species. Acinetobacter baumannii in Unit 1 and Enterobacter cloacae in Unit 2 are the common species of the three indicator families. Acinetobacter and Enterobacter in Unit 1, Escherichia, Citrobacter, Enterobacter, Klebsiella, and Hafnia in Unit 2 are the most time persistent bacterial genera along the production line. Stenotrophomonas, Serratia, Salmonella, Enterobacter, and Escherichia are common genera in both units.

Conclusion: The results obtained show no difference in the use of EB or TC as hygiene indicators. However, if the objective is to identify the species of bacterial populations, using EBs are the most appropriate.

Keywords: coliforms, enterobacteria, indicators, pasteurized milk, process hygiene, total microbial flora.

Screening of in vitro antimicrobial effects of Helicteres isora extract against Staphylococcus aureus

Research (Published online: 04-09-2021)

3. Screening of in vitro antimicrobial effects of Helicteres isora extract against Staphylococcus aureus

Sunisa Sirimongkolvorakul and Anusorn Jasancheun

Veterinary World, 14(9): 2313-2316

ABSTRACT

Background and Aim: Staphylococcus aureus is an important pathogen causing contagious mastitis in cows that need novel treatment rather than antibiotic therapy. This study aimed to investigate the antimicrobial activity of Helicteres isora extracts against S. aureus isolated from subclinical and clinical mastitis cows using an in vitro model.

Materials and Methods: H. isora pods were extracted using the following solvents: Distilled water, ethanol, acetone, and methanol. The antimicrobial activity of each extract was determined by the disk diffusion method and broth microdilution assay to assess the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC).

Results: The ethanolic extract of H. isora exhibited the largest inhibition zones against S. aureus (31.05±1.20 mm), followed by the aqueous, methanolic, and acetone extracts, respectively (26.34±1.15, 24.23±0.50, and 22.46±1.53). The ethanolic extract also had a strong inhibitory effect on S. aureus, with MIC and MBC of 0.13 and 0.52 mg/mL, respectively.

Conclusion: This study revealed that H. isora is a potential alternative natural antibacterial agent against S. aureus infection. The antimicrobial activity of H. isora is most likely mediated by phytochemical constituents.

Keywords: antimicrobial, Helicteres isora, herbs, mastitis, Staphylococcus aureus.

Antifungal and antitoxin effects of propolis and its nanoemulsion formulation against Aspergillus flavus isolated from human sputum and milk powder samples

Research (Published online: 03-09-2021)

2. Antifungal and antitoxin effects of propolis and its nanoemulsion formulation against Aspergillus flavus isolated from human sputum and milk powder samples

Alshimaa A. Hassanien, Eman M. Shaker, Eman E. El-Sharkawy and Walaa M. Elsherif

Veterinary World, 14(9): 2306-2312

ABSTRACT

Background and Aim: Aspergillus flavus causes human and animal diseases through either inhalation of fungal spores or ingestion of mycotoxins as aflatoxins produced in human and animal feed as secondary metabolites. This study was aimed to detect the incidence of A. flavus and its aflatoxins in human sputum and milk powder samples and explore the efficacy of pure propolis (PP) and propolis nanoemulsion (PNE) as natural decontaminants against fungal growth and its released aflatoxins.

Materials and Methods: A. flavus was isolated by mycological culture and identified macroscopically and microscopically. Coconut agar medium and thin-layer chromatography (TLC) were used to qualitatively detect aflatoxins in the isolated strains. Toxins were extracted from toxigenic strains by the fast extraction technique. The quantitative detection of toxin types was explored by high-performance liquid chromatography (HPLC). PNE was prepared by a novel method using natural components and characterized by Fourier-transform infrared spectroscopy, Zetasizer, and transmission electron microscopy. The effects of PP and PNE on A. flavus growth and its toxin were determined by the well-diffusion method and HPLC.

Results: The mycological culture showed that 30.9% and 29.2% of sputum and milk powder samples were positive for A. flavus, respectively. TLC confirmed the production of 61.8% and 63.2% aflatoxin by the isolated strains in sputum and milk powder, respectively. PP and PNE showed antifungal activity on A. flavus growth with mean±standard error (SE) inhibition zones of 27.55±3.98 and 39.133±5.32 mm, respectively. HPLC revealed positive contamination of toxin extracts with AFB1, AFB2, and AFG2 at 0.57±0.026, 0.28±0.043, and 0.1±0.05 mg/L, respectively. After treatment with PP and PNE, a significant decrease in AFB1, AFB2, and AFG2 concentrations was observed.

Conclusion: This study suggested using propolis and its nanoformulation as antifungal and antitoxins in human medicine and the food industry to increase the food safety level and stop food spoilage.

Keywords: aflatoxins, Aspergillus flavus, mycotoxigenic fungi, propolis nanoemulsion, propolis, Tween 80.

Molecular characterization and pathological identification of a novel strain of delta papillomavirus-4 (bovine papillomavirus-2) in Egypt

Research (Published online: 03-09-2021)

1. Molecular characterization and pathological identification of a novel strain of delta papillomavirus-4 (bovine papillomavirus-2) in Egypt

Rabab T. Hassanien, Mervat E. Hamdy, Sara M. Elnomrosy, Heba A. Hussein, Ahmed F. Afify, Fatma M. Darwish, Gehan Shehab, Rawhya Emran, Mervat I. I. Abd-El-Moniem, Ahmed R. Habashi, Hanan A. Fahmy, Essam M. Ibraheem, Momtaz A. Shahein, Mohamed Attya, Ali M.M. Abdelhakim and Naglaa M. Hagag

Veterinary World, 14(9): 2296-2305

ABSTRACT

Background and Aim: Bovine papillomaviruses (BPV) are a heterogeneous group of oncoviruses, distributed globally, which produce major economic losses. In the current study, we compared the results of different diagnostic approaches and compared the strains identified in this study with previously characterized strains at local and international levels.

Materials and Methods: Samples of skin warts were collected from five bovines with generalized papillomatosis from two Egyptian provinces, Menya and Ismailia, in 2020. Electron microscopy, molecular characterization, histopathological, and immunohistochemical examination were performed.

Results: BPV was detected using electron microscopy in the collected samples. Using molecular characterization, BPV-2 was successfully identified for 1st time in Egypt. The strain has 99.6% identity with the BPV-2 reference strains obtained from GenBank. These results were supported by histopathology and immunohistochemistry examination. Partial nucleotide sequences of the L1 gene were submitted to GenBank with accession numbers MW289843 and MW289844.

Conclusion: BPV-2 was reported for 1st time in the current study. The strain was identified grossly, microscopically, and pathologically and confirmed using molecular approaches. All results were consistent. The sequence analysis revealed that this strain has high sequence similarity to the reference Deltapapillomavirus-4, BPV-2 strains from Brazil and China.

Keywords: bovine papillomaviruses-2, first detection, histopathology, immunohistochemistry, phylogeny, transmission electron microscopy.

Evaluation of sodium lauryl sulfate for the development of cow-side mastitis screening test

Research (Published online: 31-08-2021)

40. Evaluation of sodium lauryl sulfate for the development of cow-side mastitis screening test

Nobonita Sarker Tanni, Md. Shafiul Islam, Mojahidul Kabir, Mst. Sonia Parvin, Md. Amimul Ehsan and Md. Taohidul Islam

Veterinary World, 14(8): 2290-2295

ABSTRACT

Background and Aim: Subclinical mastitis (SCM) is an economically important disease for dairy cattle worldwide; therefore, regular screening is imperative to detect SCM at an early stage so as to control it. The study was conducted to compare the test characteristics of sodium lauryl sulfate (SLS) as a test reagent to detect SCM in dairy cows.

Materials and Methods: First, 106 milk samples of dairy cows were subjected to available indirect screening tests (white side test [WST], surf field mastitis test, Leucocytest, and Immucell) considering somatic cell count (SCC) as gold standard test. Then 273 milk samples were allowed to react with different concentrations of SLS with or without sodium hydroxide (NaOH) and indicators (bromothymol blue [BTB] and bromocresol purple [BCP]).

Results: SLS with or without NaOH yielded best reaction with the milk samples similar to Leucocytest. It was observed that the reaction of milk samples with SLS added with indicators (BTB and BCP) was easier to visualize than without indicators. SLS 3%+NaOH 1.5% with BTB and SLS 2% with BCP had high sensitivity, specificity, and substantial agreement with SCC. The area under the receiver operating characteristics curve of SLS 2% with BCP and SLS 3%+NaOH 1.5% with BTB was 0.917 and 0.875, respectively.

Conclusion: It may be concluded that SLS 3%+NaOH 1.5% with BTB and SLS 2% with BCP may be the potential reagents for the development of an effective cow-side test to detect SCM, as the main ingredient SLS is considerably cheap and readily available in developing countries.

Keywords: bovine subclinical mastitis, dairy cows, screening test, sensitivity, sodium lauryl sulfate, specificity.

Effect of mangrove leaf extract (Acanthus ilicifolius) on non-specific immune status and vibriosis resistance of black tiger shrimps (Penaeus monodon) challenged with Vibrio harveyi

Research (Published online: 31-08-2021)

39. Effect of mangrove leaf extract (Acanthus ilicifolius) on non-specific immune status and vibriosis resistance of black tiger shrimps (Penaeus monodon) challenged with Vibrio harveyi

Gina Saptiani, Slamet Budi Prayitno and Sari Anggarawati

Veterinary World, 14(8): 2282-2289

ABSTRACT

Background and Aim: There has been continuous effort to search for alternative medicinal plants that are applicable to ameliorate viral disease on shrimp pond. This study aimed to examine the effect of Acanthus ilicifolius leaf extract on clinical symptoms and non-specific immune response of black tiger shrimp (Penaeus monodon).

Materials and Methods: A total of 330 shrimps were equally assigned into three extract forms (crude extract, ethyl acetate extract, and n-butanol extract, respectively) in which three levels were provided for each extract. Negative control (without leaf extract) and positive control (with oxytetracycline at 0.05 mg/mL) were used, giving a total of 11 experimental treatments.

Results: The results showed that shrimps induced into all form of leaf extracts had significantly higher survival rates, clinical symptoms, and pathological anatomy than those negative control (C–) and positive control (C+). Total hemocyte cells, granulocytes, percentage of phagocytic, and prophenoloxidase activity were similar among leaf extract treatments (p>0.05), but those groups were significantly higher than those of C– and C+ (p<0.05).

Conclusion: n-butanol leaf extract at 300 mg/L is suggested to be the most effective treatment since it showed the highest efficacy on the parameters observed. Thus, it is possible to use the leaf extract of A. ilicifolius on-farm as a strategy to enhance bacterial disease resistance and prevent mortality.

Keywords: Acanthus ilicifolius, herbal plant extract, immunity, Penaeus monodon.

Feeding value of sorghum stover fed to tropical hair sheep as complete rations in chop, mash, pellet, and block forms

Research (Published online: 30-08-2021)

38. Feeding value of sorghum stover fed to tropical hair sheep as complete rations in chop, mash, pellet, and block forms

J. Raju, J. Narasimha, N. Nalini Kumari, T. Raghunanadan, V. Chinni Preetam, A. Ashok Kumar and P. Ravi Kanth Reddy

Veterinary World, 14(8): 2273-2281

ABSTRACT

Background and Aim: Poor palatability, low bulk density, and low nutritive value restrict the utilization of the crop residues as animal feeds. Altering the physical characteristics of feed by blending the roughage and concentrates in the form of complete feed improves the nutrient use efficiency and reduces the feed wastage, feed cost, and labor cost. The study aims to determine suitable processing methods (mash, pellet, or block forms) for efficient utilization of sorghum stover-based complete rations vis-a-vis conventional feeding methods in sheep.

Materials and Methods: The sorghum stover was incorporated in complete rations with roughage to concentrate ratio of 50:50 proportion in a growth trial of 120 days. The feed ingredients were chaffed, ground in a hammer mill, passed through expander-extruder, and compressed by feed block machine to prepare chop, mash, pellet, and block form of rations, respectively. Twenty-four male intact growing Nellore×Deccani cross lambs (3.5±0.5 months age, 14.50±0.41 kg (mean ± SD) at the start of the experiment) were divided into four experimental groups of six animals each in a complete randomized design. The experimental rations were randomly allotted to each group and evaluated for their intake, nutrient utilization, and growth performance.

Results: The sheep fed on pellet-based ration consumed a higher (p<0.05) quantity of dry matter. The digestibility coefficients of organic matter, crude protein, and neutral detergent fiber were higher (p<0.05) in processed rations (mash, pellet, or block). Further, the nitrogen balance (g/d) was higher (p<0.05) in the mash, pellet, and block form of rations, compared to chopped ration. The processing method did not influence calcium or phosphorous balance parameters, except for their urinary losses, which showed an increasing trend (p=0.07). The ram lambs fed with pelleted ration showed higher (p<0.05) weight gain than mash, block, or chaff forms. The efficiency of feed utilization in gaining one kg body weight was higher (p<0.05) in lambs fed a pelleted diet. Feeding pelletized ration was more economical to gain one kg body weight. The bulk density was highest for block-based ration followed by pellet, mash, and conventional rations, and the carrying capacity of truck was highest with the least transport cost in block-form of rations.

Conclusion: Physical processing (mash, pellet, and block) of sorghum stover-based complete rations increased the nutrient utilization and growth performance of sheep compared to conventional chopped form. Pelleting the mash with expander-extruder procedure was found to be more profitable. Nevertheless, the cost economics revealed blocks as more preferable forms for transporting the complete rations to larger distances.

Keywords: block, crop residue, digestibility, feed processing, growth, lambs, mash, pellet.