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

[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 109/day spores of B. coagulans by orogastric gavage [probiotic], and standard diet with 5% w/w long chain inulin and 109 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.

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

Antimicrobial activities of oregano and nutmeg essential oils combined with emulsifier/stabilizer compound in ready-to-cook barbecued chicken

The effects of essential oils [Eos] of oregano and nutmeg with and without commercial emulsifier/stabilizer compound [E/S] on the microbial quality of ready-to-cook barbecued chicken were evaluated. Barbecued chicken was traditionally prepared. 3 microL/g and 10 mg/g of EOs and/or E/S were then added to the barbecued chicken, respectively. The samples were stored at 3°C for 144 h, 8 and 20degreeC for 72 h, accordingly, prior to being subjected to enumeration of aerobic mesophilic and psychrotrophic bacteria at different storage times. No inhibitory effects were detected in the presence of nutmeg EO together with and/or without E/S on the psychrotrophic and aerobic mesophilic counts [AMC] in barbecued chicken. Whereas, AMC and psychrotrophic counts in the samples treated with oregano EO, stored at 8 and 20°C were not dramatically changed. Even though, in the case of treatment with oregano EO and E/S, stored at 3, 8 and 20°C AMC and psychrotrophic counts were significantly affected. Oregano EO was an active antibacterial component, used in combination with commercial E/S, compared to its single use. It can be suggested that using E/S and EO in combination is more likely able to emulsify antimicrobial EO substances and thus increase the efficacy of such substances

[First detection of Sarcocystis hirsuta from cattle in Iran]

Although the high infection rate of microscopic sarcocyst occurs in cattle, to the best of our knowledge, there is no report about the identification of macroscopic sarcocyst in Iran. In this work, Sarcosystis hirsuta was first isolated from slaughtered cattle. In a 2-year-old slaughtered cattle, morphological examination revealed 3-5 mm in length cysts distributed in different striated muscles, particularly intercostalis and diaphragm. In electron microscopy study, ultramicroscopic structure of primary cyst wall based on the presence of cone-shaped villar protrusions confirmed the occurrence of S. hirsute

Effect of adding inulin on microbial and physico-chemical properties of low fat probiotic yogurt

Currently, due to their beneficial effects, there is interest in adding prebiotics to food products. This study investigated the effect of the addition of inulin [1% and 2%] on microbial and physico-chemical properties of probiotic low fat yogurt manufactured with Lactobacillus acidophilus. Six experimental preparations of yogurt were produced. Homogenized, standardized and pasteurized low fat milk were divided into six portions. Four portions were fortified with 1% and 2% inulin and two portions were used without inulin. All of the preparations were heated up to 85 [degree sign] C and fermented at 43 [degree sign] C until a pH of 4.6 was reached. Titratable acidity and pH were determined using the incubation period of the samples and a storage time up to 14 days. Syneresis, color, sensory evaluation and bacterial counts were determined during the storage time. The results showed that inulin did not significantly affect the titratable acidity and pH of the yogurts after 4 h of fermentation at 40 [degree sign] C. There were no significant differences between pH, titratable acidity, syneresis, color and sensory evaluation of all treatments on days 1, 7 and 14 of storage. The counts of L. acidophilus and L. delbrueckii ssp. bulgaricus declined over time, but the addition of inulin to the milk increased the viability of these bacteria during the storage of symbiotic yogurt. In conclusion, inulin can be used to manufacture low fat symbiotic yogurt with additional nutritional benefits without affecting the physic-chemical properties of yogurt

[Comparative studies on the effect of the enzyme ficin on the solubility and electrophoretic pattern of ovine and bovine meat proteins]

Different techniques have been employed to improve the technological properties of meat. One of the most important techniques is adding proteolytic enzymes which could simultaneously increase the tenderization and solubility of meat proteins. The purpose of this investigation was to study the effect of different levels of the enzyme ficin on ovine and bovine meat and to determine the best condition for solubilization of meat proteins. Ficin was partially purified from figs tree latex by cationic exchange chromatography. Meat samples were treated wilh different activities of ficin and the effect ofenzyme was followed by measuring nitrogen solubility index [NSI] and electrophoresis. NSI was determined by homogenization of ficin-treated meat in the presence of buffers, centrifugation and nitrogen determination of the supernatant by kjeldal. The solubility of meat proteins increases with increase in the activity of added ficin and with increase in the incubation time [p<0.001]. Presence of salt significantly increased the solubility of meat proteins up to 65% [p<0.01]. The SDS-PAGE pattern of soluble proteins showed the molecular weight of proteins was in the range of 15-105 KDa and was similar in ovine and bovine meat. Also by increasing the unit activity of enzyme form 0.8 to 2.6 units. most protein bands were disappeared or decreased in intensity. These results indicated that the velry high activity of ficin results in disruption of the structure of myofibrillar proteins and excessive break down of these proteins to smaller peptides which either precipitate or cannot be detected by electrophoresis

[Microbialnd chemical changes of raw milk in various stages of production in industrial dairy farms of Fars province]

With aim for Identification of contaminative and critical points of raw milk during production in 9 selected industrial dairy farms, 408 raw milk samples were collected from udders, milking machine, cooling tank and milk transport vehicle at receiving platform in dairy plant. Samples were examined for total microbial, coliform and E.coli count and also acidity and pH. Total microbial count of Samples was significantly lower in udders than the later stages [p<0.001]. Coliform count of Samples increased significantly from udders to cooling tank and milk transport vehicle at receiving platform in dairy plant [p<0.05]. There were no significant differences, [p>0.05] among the E. coli count at the different stages. High total microbial count in udder milk samples and significantly increase of this factor and acidity in milking, machine stage imply to localize executive, educational and investigative activity on this crisis points

Effects of oral administration of monensin on serum glucose, AST, and arginase of holstein cows during transition period

In the present study, under typical management conditions of dairy farms in Iran, the effect of oral administration of on serum glucose, AST and arginase[indices of liver injuries] of oral monensin was assessed. Thirteen multiparous Holstein cows were blocked into a control and an experiment group from 3 weeks prepartum to 45 days postpartum according the number of their calvings. The groups received similar diets. The experiment group received monensin added to grain mix at 340 mg/head/day during prepartum weeks, 160-480 mg/head/day during first two weeks postpartum, and 350 mg/head/day during days 15-45 postpartum. Blood samples were obtained at days -20 and -10 prepartum, and days 4, 15, 25, 35 and 45 postpartum to determine serum glucose, AST, and arginase. Serum glucose decreased significantly [p = 0.025] in the control group from day 10 prepartum to day 15 postpartum. In the experiment group it increased significantly [p = 0.049] from the beginning of the experiment to day 35 postpartum. On day 15 postpartum, serum glucose showed a tendency [p = 0.07] for significant difference between groups. The level of ASTwas higher in the experiment group from day 10 prepartum to day 25 postpartum with a significant difference [p = 0.011] on day 10 prepartum. There was no significant difference in serum arginase activity between control and experiment groups [p > 0.05]. Administration of monensin mixed with diet can result in better functions of the liver, increase [or prevention of decrease] in serum glucose during peripartum weeks. It appears that changes in the dose of the drug during the early postpartum days [due to changes in dry matter intake] cannot affect the positive effect of monensin. The positive effect of monensin can be started prepartum; thus, its administration from prepartum transition period continued to postpartum weeks is recommended

Effects of oral administration of monensin on milk yield, milk economic components and iodine value of milk fat in holstein-friesian cows in early lactation

Assessing the effects of monensin on economic factors of milk [percents of protein and fat], and quality of milk fat during early lactation. Thirteen multiparous Holstein cows were blocked into a control and a treatment group from 3 weeks prepartum to 45 days postpartum according the number of their calving. The groups received similar diets. The treatment group received monensin added to grain mix at 340 mg/head/day during prepartum weeks, 160-480 mg/head/day during first two weeks postpartum and 350 mg/head/day during days 15-35 postpartum. Milk samples were obtained on days 15, 25, 35 and 45 postpartum. Milk volume during a standard period of 305 days and during the first 3 months of lactation, percentages milk protein and milk fat and iodine value of milk fat were determined. Data were studied with the SPSS statistical software using analysis of variance for repeated measures and independent t test. No significant differences were observed between control and experiment groups in volumes of milk during the first 3 months of lactation and the standard production of the entire lactation period. The natural decrease in the percentage of milk protein and fat postpartum was observed in both groups. However, the pattern of decrease in milk protein was slower in the treatment group. There was no difference between the groups in milk protein at various stages of sampling. Milk fat increased in the treatment group from day 25 of lactation and on day 45, it was significantly higher in the treatment group than in the control cows. The iodine index of milk fat was nonsignificantly higher in the treatment group throughout of the experiment. The present study showed that administration of monensin during periparturient weeks has no adverse effect on milk volume, percentage of milk protein and fat and the quality of milk fat. It may lessen the decreasing pattern of milk protein and fat, or accelerate the time for their increasing. Increased level of unsaturated fatty acids in milk is a positive point in feeding monensin

Changes of milk fat, crude protein, NPN and protein: fat ratio in holstein cows fed a high concentrate diet from early to late lactation

Percentages and yields of fat, crude protein [CP], true protein [TP] and non-protein nitrogen [NPN] were assessed in milk of four groups of Holstein cows, at early, mid and late lactation [days in milk 20-70, 71-110. 111-150 and 151-210], on a diet rich in concentrates during a hot summer. Four milk samples were taken from individual cows at 10-day intervals. Milk fat percentages were close to breed average and increased toward the end of lactation with a tendency [P = 0.055] for significant difference between the early and late lactation. Percentages of CP [P = 0.14] and TP [P = 0.478], however, were low similarly among all groups and did not follow the normal pattern of the breed. Percentage of NPN was significantly higher in groups Ill and IV [P = 0.005]. Yields of fat [P = 0.035], CP [P = 0.002] and TP [P = 0.001], but not NPN [P = 0.589], decreased toward the end of lactation. There was a negative correlation [r = -0.354, P<0.001] between the percentages of NPN and TP. However, no correlation was observed between the percentages of NPN and CP. Despite a very strong correlation between yields of CP and TP [r = 0.983, P<0.001], the correlation between the yield of CP and that of NPN was much weaker [r = 0.473, P<0.001]. It is concluded that percents and yields of milk fat, close to breed average are attainable at any stage of lactation on high concentrate diets in hot weather. However, regarding milk protein, cows may not perform well. TP may be more affected than CP

Effects of acidity, fat and solid non fat content of milk on destruction of Listeria monocytogenes biotype 4b by microwave radiation

The efficacy of microwave radiation in destruction of Listeria monocytogenes Shiraz bio-Iran.type 4b in milk with various concentrations of solid non fat [SNF], fat and acidity were studied. Experimental study. Bacterial suspensions [about 1.5x10[7] CPU ml[+1] in milk containing various concentrations of SNF [7.5 and 8.5percent],fat [2.5,3.0and3.5percent] andacidity [1.6,1.7 and 1.8 g L' lactic acid] were prepared in volumes of 50 ml. Then the samples were exposed to microwave radiation in triplicate for 0,10,20,23,26,29,32,35 and 40 seconds and the viable cell count was performed with standard plate count method. Repeated Measures ANOVA and Duncan's tests were employed to determine the differences in the rates of bacterial destruction in the milk samples after irradiating. Under different durations of radiation, a useful effect of bacterial killing by microwave irradiation was observed. Reduction in viable cell count was significantly faster when the SNF and/or fat concentration of milk increased. The speed of decline in cell populations was significantly slower when the acidity increased. Contrary to the conventional heating process, the present study showed that the destructive effect of microwave heating increased by increasing the SNF and fat concentration of milk. Although, pH of some foods and culture media within the range of 5.5-7.0 had no significant effect on destruction properties of microwave, milk acidity affected it significantly. It seems that increased acidity causes increased ionic content of milk, which in turn results in lower penetration of microwave into milk

Changes in and correlations between some serum constituents and milk components from early to late lactation in a dairy herd with subclinical production disorders

Changes in some serum constituents and milk components and correlations between them, were used for defining the reason [s] of suboptimal milk composition in a dairy herd with a history of low protein tests during summers. Four groups of 8 adult Holsteins, 20-70, 70-110, 110-150 and 150-210 days in milk [DIM], under heat stress, with similar feeding and management practices were sampled for blood and milk four times on a 10 day interval. Milk volume, percentages of milk fat and protein and levels of serum glucose, total protein, albumin and BUN were determined. Milk volume decreased as DIM increased [P<0.05]. Milk fat showed normal changes, but milk protein was similarly low in all groups [P>0.05], showing probable shortages in energy and/or protein intake. Serum parameters showed no significant differences among groups [P>0.05]. Weak positive correlations were found between serum total protein and milk components after 150 DIM [maximum correlation with milk fat, r = 0.61]. It is concluded that shortage in intake of energy and/or protein, which may result in lowered milk protein, may not be differentiated by measuring serum glucose, total protein, albumin and BUN and milk components. More detailed experiments on serum and milk are necessary for defining the problem properly

[Study on prevalence of Sarcocystis in slaughtered cattlein Shiraz]

Study on the prevalence of macroscopic and microscopic cysts of Sarcocystis in slaughtered cattle by direct inspection, impression smear and digestion method. Cross-sectional study. Two hundreds of cattle slaughtered at Shiraz slaughterhouse. Simple random sampling, determination of sex and age, direct inspection of esophagus, tongue and different muscles to find macroscopic cysts, sampling from tongue, heart, diaphragm and esophagus, preparing tissue smear and staining by Giemsa, digesting samples by PBS containing HC1 and pepsin, staining the precipitate by Giemsa, and examining the stained smear for bradyzoites. No macroscopic cyst was observed. All samples in digestion method and 99% of them in impression smear method were diagnosed to be infected by microscopic cysts. The sensitivity rate of impression smear method to diagnose the microscopic cysts was 72.0% in esophagus, 78.5% in diaphragm, 79.5% in tongue and 98.5% in heart. Sex and age had no effect on infection rate. There was no significant difference among infection rates of different organs.According to high infection rate of cattle with microscopic cyst, the identification of Sarcocystis spp and their prevalence rate is very important. S.cruzi causes Dalmeny disease in cattle and S.bovihominis causes intestinal sarcocystosis in humans. The latter is transmitted by consumption of infected beef. Avoiding consumption of under-cooked beef is highly advisable in infected areas which are world wide in distribution