Immunological and bacteriological quality of fresh cow colostrum and passive immunity transfer in selected dairy farms in Fars, Iran.

Background: The quality of colostrum is affected by IgG level and microbial load. Aims: The quality of colostrum used in feeding dairy calves and passive immunity transfer in selected dairy farms in Fars province, Iran was investigated. Methods: A total of 75 colostrum and neonatal blood samples were collected from 11 herds. The immunological quality of colostrum was assessed using a Brix digital refractometer. The bacteriological quality was assessed by performing total plate count (TPC), total coliform count (TCC), spore-former count, fungi count, and species-specific PCR assay to detect some bacterial species. Results: The mean Brix of colostrum samples was 25.4% and 72% of the samples had a Brix score ≥22%. The mean serum Brix and the prevalence of failure of passive transfer (FPT) were 10% and 4%, respectively. The mean TPC, TCC, spore-former count, and fungi count were 3.6 × 105, 2.8 × 104, 3.2 × 104, and 1.1 × 104 CFU/ml, respectively. The results showed that 50, 5.9, and 4% of colostrum samples were positive for Staphylococcus spp., Salmonella spp. and Maycobacterium paratuberculosis, respectively. There was no evidence of contamination with Brucella spp., Corynebacterium bovis and Mycoplasma bovis. Conclusion: Considering all colostrum quality indicators comprehensively, only 37.3% of the studied samples met the industry standard. A large number of calves were at risk of receiving poor quality colostrum, especially in terms of microbial contamination. Further researches are needed to evaluate the colostrum management and the effect of bacterial contamination of colostrum on the health of neonate calves in this region.

Evaluation of the properties and antibacterial activity of microchitosan film impregnated with Shirazi thyme (Zataria multiflora) and garlic (Allium sativum) essential oils.

Background: Recent research has shown that chitosan has good moisture-absorbing properties at the micro and nanoscale, and seems to be a good candidate for the production of biodegradable moisture-absorbing films. Aims: The aim of this study was to evaluate the properties and antibacterial activity of starch-based microchitosan (MCH) films impregnated with two essential oils (EOs). Methods: MCH films with varying thicknesses were made from cornstarch (6%), microchitosan (1%), glycerol (2.25%), and/or EOs (2%), and their characteristics, including swelling degree (SD), tensile strength (TS), and elongation at break (EB%), were examined. The film structures were confirmed by X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM). To determine the antibacterial activity against Escherichia coli and Staphylococcus aureus, two EOs of Shirazi thyme, garlic, and a mixture of them were used in the experimentation. Results: The EB% and TS had a linear relationship with the thickness of samples and improved by increasing the thickness of films. The XRD pattern showed that the MCH films had an amorphous structure. SEM of the films showed a homogeneous dispersion of MCH in the starch matrix without any porosity. The AFM images showed a simultaneous increase in the thickness of the MCH films and surface roughness. The film was able to absorb water up to 15.78 times its weight in 48 h. The inhibition zone of films containing 2% thyme EO was 42.0 mm for S. aureus and 12.3 mm for E. coli (P<0.05). Conclusion: MCH film containing Shirazi thyme can be described as a moisture-absorbing antibacterial pad and is a new idea for active food packaging to increase the shelf life of foods with fully degradable properties.

Alteration of fatty acid profile of milk in Holstein cows fed Bacillus coagulans as probiotic: a field study.

BACKGROUND: Probiotics may improve milk quality and the general health status of animals. AIMS: The effects of dietary Bacillus coagulans PRM101 on milk components, milk fatty acids (FA), and some health indicators of dairy cows were investigated. METHODS: The probiotic was added to the feed of 12 Holstein cows (2 g/cow: 2 × 1011 CFU/cow) for 63 days compared to a control group fed on the basal ration (n=11). Milk and blood samples were taken on days 0, 21, 42, and 63. RESULTS: The yields of milk and energy corrected milk (ECM; computed from milk weight and its fat and protein content) decreased linearly and similarly (P=0.60) in both groups. The treatment cows, however, showed quadratic increases in the weights of milk (P=0.03) and ECM (P=0.04) at d42 of the study. Energy corrected milk (d42, P<0.05) and crude protein content of milk (d42, P<0.05; d63, P<0.1) were higher in the cows receiving the probiotic. The proportions of heptadecanoic (C17:0; P=0.002) and linoleic (C18:2; P=0.077) acids in milk fat (g/100 g fat) were higher in the treatment cows on d63. Milk total antioxidant capacity (TAC), malondialdehyde (MDA), and similarly, amyloid A (AA) and haptoglobin (Hp) of milk and blood were not affected. Total antioxidant capacity and MDA were negatively correlated in the control group (r=-0.669, P=0.005). Heptadecanoic acid correlated negatively with milk MDA (r=-0.611, P=0.035) and positively (r=0.591, P=0.043) with serum Hp in the treatment cows. CONCLUSION: Dietary B. coagulans PRM101 may improve the proportions of C17:0 and C18:2 FA in milk. Some improvements in milk protein and the health status of the cows may also be anticipated.

The effect of carboxymethyl cellulose coating incorporated with clove oil nanoemulsion on quality of shrimp (Litopenaeus vannamei) during refrigerated storage.

BACKGROUND: The quality of shrimp, as high perishable seafood, can readily be effected by microbial, chemical, and physical alterations during storage. AIMS: In this study, carboxymethyl cellulose (CMC) coating either alone or incorporated with variable levels of clove oil nanoemulsion (CNE) (10, 20, and 30 mg/ml) was developed to sustain the quality of shrimp during refrigerated storage. METHODS: Changes in microbial, chemical, textural, color (L*, a*, b*), and sensory parameters of the studied groups evaluated through distinct experimental approaches. RESULTS: Based on our results, the pattern of increase in the aerobic plate count (APC) and psychrotrophic bacterial count (PBC) in different groups were reported as the following order: CMC + CNE < CMC < control. Also, CMC and CNE integration decreased the upward trend of total volatile basic nitrogen (TVB-N), and thiobarbituric acid reactive substances (TBARS) compared to that of the control group during storage at 4°C for 10 days (P<0.05). During the storage period, the decrease of the L* value in the control group was greater than the others; whereas, the lowest a* and b* values were observed in this group (P<0.05). Besides, the textural and sensory properties of coated shrimp were significantly more acceptable (P<0.05). CONCLUSION: Integration of CNE in CMC coating promisingly improves the quality of shrimp during refrigerated storage.

The use of inulin as fat replacer and its effect on texture and sensory properties of emulsion type sausages.

The present study aimed to investigate the possibility of reducing energy content in emulsion type sausages by replacing fat with inulin. In the manufactured product, the fat content was reduced to 6%-18% and replaced by inulin and water. The quality of the resulting product was determined by chemical and texture profile analyses (TPA), color measurement and sensory evaluation. The results showed that replacing fat with inulin led to a significant energy content reduction of up to 64% (with 6% inulin and 12% water). In addition, color measurement, sensory evaluation and TPA were comparable to the traditional product in the inulin treated samples. The overall acceptability of all experimental groups was adequate; therefore, inulin is suggested as a good replacement for fat in emulsion type sausages.

The effects of probiotic, prebiotic and synbiotic diets containing Bacillus coagulans and inulin on rat intestinal microbiota.

An in vivo experiment was conducted to study the effects of probiotic Bacillus coagulans spores, with and without prebiotic, inulin, on gastrointestinal (GI) microbiota of healthy rats and its potentiality to survive in the GI tract. Forty-eight male Wistar rats were randomly divided into four groups (n=12) and fed as follows: standard diet (control), standard diet supplied with 5% w/w long chain inulin (prebiotic), standard diet with 10(9)/day spores of B. coagulans by orogastric gavage (probiotic), and standard diet with 5% w/w long chain inulin and 10(9) spores/day of B. coagulans by orogastric gavage (synbiotic). Rats were fed the diets for 30 days. At day 10, 20 and 30 of experiment, 24 h post administration, four rats from each group were randomly selected and after faecal collection were sacrificed. Small intestine, cecum, and colon were excised from each rat and used for microbial analysis. Administration of synbiotic and probiotic diets led to a significant (P<0.05) increment in lactic acid bacteria (LAB), total aerobic and total anaerobic population compared the prebiotic and control diets. A significant decrease in Enterobacteriaceae counts of various segments of GI tract (except small intestine) in synbiotic, probiotic and prebiotic fed groups were also seen. The obvious decline in spores count through passing GI tract and high surviving spore counts in faecal samples showed that spores are not a normal resident of GI microbiota and affect intestinal microbiota by temporary proliferation. In conclusion, the present study clearly showed probiotic B. coagulans was efficient in beneficially modulating GI microbiota and considering transitional characteristics of B. coagulans, daily consumption of probiotic products is necessary for any long-term effect.

Association between the enterotoxin production and presence of Coa, Nuc genes among Staphylococcus aureus isolated from various sources, in Shiraz.

The present study was aimed to identify the frequency of coagulase (Coa) and thermonuclease (Nuc) genes and Staphylococcal enterotoxin A (Sea) production among Staphylococcus aureus isolated from various sources in Shiraz. Moreover, the correlation between the Sea gene and coagulase and thermonuclease enzymes is also considered. A total of 100 S. aureus were isolated from various sources including 40 humans, 30 animals and 30 food samples by the routine biochemical tests. The frequency of Coa, Nuc and Sea genes was evaluated by PCR assay. Correlation among those genes was finally evaluated by statistical analysis. The PCR results showed that the prevalence of Coa, Nuc and Sea genes was 91%, 100% and 14%, respectively. The evaluation of the enterotoxin production indicated that 78.6% of the Sea gene was expressed. The presence of enterotoxin A was not necessarily correlated to the production of toxin. As a final conclusion to detect the enterotoxigenic strains, both genotypic and phenotypic methods are highly recommended.

Phenotypic and genotypic diversity of dominant lactic acid bacteria isolated from traditional yoghurts produced by tribes of Iran.

Morphological, biochemical and molecular characteristics were studied to identify dominant lactic acid bacteria (LAB), isolated from traditional yoghurts produced by tribes of Iran. From 60 yoghurt samples, a total of 137 LAB isolates were determined, in which 66 and 71 were identified as lactic acid cocci and bacilli, respectively. Biochemical tests showed the occurrence of 9.76% mesophilic homofermentative, 10.98% mesophilic hetrofermentative, 26.83% thermophilic homofermentative and 47.56% mesophilic homofermentative cocci. As for lactic acid bacilli, mesophilic facultative hetrofermentative (26%); thermophilic obligate homofermentative (56%); mesophilic obligate hetrofermentative (18%) were found. Genetically the presence of the following species were verified: E. faecium; E. faecalis; E. durans; L. lactis subsp. lactis; St. thermophilus; Lb. delbruecki subsp. bulgaricus; Lb. brevis; Lb. diolivorans; Lb. helveticus; Lb. jensenii; Lb. plantarum. 9% of the Lactobacillus isolates showed incompatible results between phenotypic and genotypic characteristics. From the cocci isolates, 38.46% showed identical results between phylogenetic characteristics. The current study constitutes the first step in the designing process of LAB starter cultures, to protect the typical organoleptic characteristics of traditional yoghurt. The results could also be used to introduce new starter cultures for commercial use.

An epidemiological survey on the determination of Taenia saginata cysticercosis in Iran, using a PCR assay.

Bovine cysticercosis caused by Taenia saginata is a zoonotic disease affirming routine inspection measures for the postmortem detection of cysticerci (cysts) in beef destined for human consumption. Detection is based on gross examination of traditional carcase predilection sites; although there is evidence to suggest that examination of other sites may offer improvements in sensitivity. In the current study, a biomolecular-based assay was employed to confirm and differentiate T saginata cysticercosis from other comparable parasitic infection in cattle carcases. Out of 7371 cattle carcases routinely inspected, 72 (0.97 per cent) were initially detected, from which 57 (79.16 per cent), 11(15.27 per cent) and 4 (5.55 per cent) were recorded in masseter muscle, heart and diaphragm, respectively. The PCR assay was also conducted to confirm different stages of the cysts, being able to detect the cyst, and to discriminate its various degenerative stages with other parasitic structures. The technique was proposed as a reliable tool to differentiate the cysticerci and, thus, could be used in further epidemiological studies as there was no difference in view of negative PCR results in lesions found by routine inspection.

Effect of actinidin on the protein solubility, water holding capacity, texture, electrophoretic pattern of beef, and on the quality attributes of a sausage product.

The objective of this study was to study the effect of actinidin, a sulfhydryl protease from kiwi fruit, on the protein solubility (nitrogen solubility index [NSI]), water holding capacity (WHC), texture, and SDS-PAGE pattern of beef and to evaluate the effect of pretreatment of beef with actinidin on the quality attributes of a sausage product. Actinidin was partially purified by precipitation with ammonium sulfate, followed by DEAE-Sephadex column chromatography. Actinidin significantly (P < 0.05) increased NSI and WHC of beef; the highest NSI and WHC (approximately 20% and 8% increase, respectively) was observed when beef was incubated with 0.9 unit enzyme/g beef. Texture analysis indicated increased tenderization (10% decrease in shear force) when slices of cattle beef were treated with actinidin at 37 degrees C for 2 h. SDS-PAGE results indicated appearance of several low molecular weight bands (<10 kDa) after treating beef with different levels of actinidin for 30 or 60 min. Slight changes in protein band in the range of 100 to 120 kDa and 13 to 25 kDa were also observed. Use of actinidin-tenderized beef significantly improved emulsion stability, texture, and organoleptic properties of the sausage product.

Prevalence of Linguatula serrata nymphs in one-humped camel (Camelus dromedarius) in Najaf-Abad, Iran.

The prevalence of Linguatula serrata nymphs in livers and mesenteric lymph nodes (MLNs) of 400 camels of different sex and age groups was investigated. The lymph nodes and livers were examined macroscopically. A digestion method was also applied for investigation of liver samples. The MLNs in 84 camels out of 400 (21.0%) and the livers of 18 camels out of 400 (4.5%) were infected by L. serrata nymphs. The infection rate increased with age (p<0.01). No significant difference was observed between the prevalence in males and females (p>0.1). It is concluded that consumption of raw or under-cooked camel liver may result in nasopharyngeal linguatulosis in humans.

Effects of essential oils of oregano and nutmeg on growth and survival of Yersinia enterocolitica and Listeria monocytogenes in barbecued chicken.

The in vitro effects of plant essential oils (EOs) against pathogenic bacteria are well known, yet few studies have addressed the effects of these compounds against pathogens associated with ready-to-cook foods. Experiments were conducted to determine the effectiveness of oregano and nutmeg EOs on the growth and survival of Yersinia enterocolitica and Listeria monocytogenes in broth culture and in Iranian barbecued chicken. Ready-to-cook Iranian barbecued chicken was prepared according to the common practice with 1, 2, and 3 microl/g of oregano and nutmeg EOs. The test and control (without EOs) samples were inoculated with Y. enterocolitica and L. monocytogenes to a final concentration of 6 to 7 log CFU/g and stored at 3, 8, and 20 degrees C. Microorganisms were counted just before and at 24, 48, and 72 h after storage based on growth on Yersinia selective agar supplemented with cefsulodine, igrasan, and novobiocin and on Listeria selective agar supplemented with nalidixic acid and acriflavin. In the broth culture system, the nutmeg EO had a greater effect on L. monocytogenes (MIC = 0.20 nicrol/ml) than did the oregano EO (MIC = 0.26 microl/ml). However, the oregano EO had a greater effect on Y. enterocolitica (MIC = 0.16 microl/ml) than did the nutmeg EO (MIC = 0.25 microl/ml). In ready-to-cook Iranian barbecued chicken, the log CFU per gram of both bacteria after up to 72 h of incubation was not decreased significantly by various combinations of oregano and nutmeg EOs (1, 2, and 3 microl/g) and storage temperatures (3, 8, and 20 degrees C) when compared with control samples (without EOs). Although examination of spices in culture media can yield accurate microbiological data, without complementary tests in foods these data are of limited value for assessing food safety.

Effect of monensin on serum lipoproteins, triglycerides, cholesterol and total lipids of periparturient dairy cows.

Serum concentrations of very low-density lipoproteins (VLDL), low-density lipoproteins (LDL), high-density lipoproteins (HDL), triglycerides, cholesterol, and total lipids of a group of monensin-treated cows (n = 7) were compared with those of a control group (n = 6) from about 10 days before calving to 45 days postpartum. Monensin was fed in the diet from about 20 days before predicted calving date to 45 days after parturition. Blood samples were obtained on days 20 and 10 before predicted calving, and on days 4, 15, 25 (phase I), and days 35 and 45 (phase II) post calving. Cholesterol (p = 0.046) and total lipids (p = 0.003) were lower in the treatment group 10 days before calving. Concentrations of serum triglycerides and VLDL (p = 0.017), and that of LDL (p = 0.032) were significantly higher in the treatment group in phase I postpartum. No significant difference was detected between groups during phase II. Comparison of the entire length of the trial showed higher concentrations of triglycerides and VLDL in the treatment group (p = 0.009). It is concluded that monensin is effective in increasing secretion of triglyceride-rich lipoproteins from the liver during the postpartum transition period of dairy cows. This may be effective in reducing the intensity of hepatic lipidosis and the incidence of periparturient diseases resulting from disturbances in energy metabolism.