Molecular characterization of Brucella melitensis Rev.1 strain in aborted sheep and goats in Iran

Live attenuated Brucella melitensis Rev.1 strain is currently used in some countries against caprine and ovine brucellosis. Although live B. melitensis Rev.1 strain is considered the best vaccine available for the prophylaxis of brucellosis in sheep and goats, its residual abortifacient potential in pregnant animals is still a problem. We used a specific PCR–RFLP method to distinguish B. melitensis Rev.1 from other Brucella field isolates derived from aborted fetuses of sheep and goats in Iran. Molecular typing of 46 Brucella spp. isolates revealed that five strains were B. melitensis Rev.1 vaccine strain.     

Aflatoxin B1 levels in feedstuffs from dairy cow farms in south of Iran

Aflatoxin B1 (AFB1) occurrence was determined in 359 different feedstuff samples supplied to 144 dairy cow farms of the Fars province, and its levels were compared with Iranian legal regulation. Quantitative analysis of AFB1 was performed by competitive enzyme-linked immunosorbent assay. The contamination rate and overall mean level of AFB1 in the all samples were 94.81% and 4.12?±?0.53?μg?kg^?1, respectively. The level of AFB1 in 36 samples (10.94%) was higher than the maximum accepted levels for animal feed (5?μg?kg^?1) in Iran and the European Commission. The mean of AFB1 levels exceeded the maximum accepted levels in Iran for corn, alfalfa hay and soybean meal feedstuffs. The time of sampling unlike the geographical area and the type of farms significantly (P?相似文献   

Phenotypic and molecular characteristics of Streptococcus agalactiae isolates recovered from milk of dairy cows in Brazil

Information on the characteristics of Streptococcus agalactiae obtained from bovine sources in Brazil is still very limited. The aim of this study was to assess the phenotypic and genotypic diversity among S. agalactiae isolates from milk of dairy cows presenting clinical or subclinical mastitis in the southeast region of Brazil. Phenotypic characterization was based on physiological and serological tests. Antimicrobial susceptibility tests were carried out by the disk method. Genetic diversity was evaluated by using random amplified polymorphic DNA-PCR (RAPD-PCR) (by using the primer 1254) and pulsed-field gel electrophoresis (PFGE) (by using SmaI as the restriction enzyme) and by PCRs for detection of genes associated with resistance to erythromycin and tetracycline as well as PCRs for detection of genes coding for cell surface-associated proteins. According to the results of physiologic tests, 45 (52.9%) isolates showed beta-hemolysis and 44 (51.7%) were susceptible to bacitracin. Fourteen different biotypes were detected. The two most frequent biotypes comprised strains that were non-beta-hemolytic; fermented galactose, lactose, and salicin; produced protease; and were negative for DNase production. Serotype III was predominant (66 isolates [77.6%]), followed by serotypes II, Ia, Ib, and VI. Resistance to tetracycline and erythromycin was found in 38 (44.7%) and 9 (10.5%) isolates, respectively, with tet(O) (31.7%) and erm(B) (100%) being the most frequently occurring resistance genes. Three genes coding for surface proteins, bca, lmb, and scpB, were detected in 55 (64.7%), 7 (8.2%), and 43 (50.5%) isolates, respectively. In most cases, isolates from animals in the same herd presented closely related genetic profiles (determined by either RAPD-PCR or PFGE), which were distinct from those of isolates from different herds.     

Immunization against Q-fever of naturally infected dairy cows.

Dairy cows infected naturally with Coxiella burnetii as evidenced either by presence of phase II agglutinating antibodies in the blood or by shedding C. burnetii in the milk, were vaccinated subcutaneously with formalin-killed phase I C. burnetii organisms. Attempts to demonstrate C. burnetii in the milk of vaccinated dairy cows 47 days after vaccination were negative, while continuous shedding of C. burnetii in the milk of control non-vaccinated dairy cows was repeatedly demonstrated in the course of 123 days (period of investigation). No harmful systemic reaction following vaccination was observed.     

Bone-specific alkaline phosphatase activity in dairy cows

Bone-specific alkaline phosphatase is considered the single most accurate marker of bone formation. In this study, 75 healthy Holstein dairy cows in their first, second, third, fourth or fifth parities underwent serum bone-specific alkaline phosphatase quantification. The results indicate that enzyme activity values have a decreasing pattern with increasing order of parity (p < 0.05). However, the differences between cows in second and third parity and also between cows in fourth and fifth parity were not statistically significant (p > 0.1). We concluded that bone-specific alkaline phosphatase measurement by heat inactivation provides a simple method to determine bone metabolic status and useful data to evaluate calcium availability in dairy cows.     

Real-time multiplex PCR assay for detection of Brucella spp., B. abortus, and B. melitensis

The identification of Brucella can be a time-consuming and labor-intensive process that places personnel at risk for laboratory-acquired infection. Here, we describe a real-time PCR assay for confirmation of presumptive Brucella isolates. The assay was designed in a multiplex format that will allow the rapid identification of Brucella spp., B. abortus, and B. melitensis in a single test.     

Fatty liver syndrome in dairy herds in southeast Iran

Fatty liver syndrome is a metabolic disorder that is caused by negative energy balance in high-producing dairy cows during early lactation. The diagnosis of fatty infiltration of the liver in dairy cattle is presently based mostly on biochemical analysis, biopsy, and histological analysis of hepatic tissue. In this study, a total of 287 dairy cows in early lactation (1–4 weeks postpartum) were randomly selected from 14 commercial dairy herds in southeast Iran. Blood samples from all of the cases, midstream urine samples from 46 of 287 cattle, and liver samples from 94 of 287 cows that were slaughtered due to other postparturient disorders were collected. A spectrophotometer was used to measure the levels of aspartate aminotransferase and glucose concentrations in the serum samples. Ketone bodies were detected by highly sensitive test strip method in the urine samples. The submersion of liver samples into water and copper sulfate solutions with specific gravities of 1.025 and 1.055 was used as a test to estimate lipid contents. Formalin-fixed liver samples were stained with hematoxylin and eosin and confirmed by the Sudan IV staining method on frozen sections. Fatty liver syndrome was detected in ten out of 14 dairy herds. Eleven (11.7%) postpartum cows were suffering from mild (13% < fat content < 25%) fatty liver, and ketone bodies were detected in five (11.11%) urine samples from a total 46 cows. All of the five cases were suffering from hypoglycemia (serum glucose concentrations <45 mg/dl) and mild hepatic lipidosis. In conclusion, the results of this study show that the prevalence of fatty liver syndrome in dairy herds in southeast Iran is considerable. Furthermore, proper nutritional programs for the early lactating cows will prevent the disease.     

Effect of antibiotics contained in two Brucella selective media on growth of Brucella abortus, B. melitensis, and B. ovis.

The MIC and the highest concentration enabling bacterial growth (CEG) of the antibiotics contained in two selective media were determined for Brucella abortus, B. melitensis, and B. ovis. The nalidixic acid and bacitracin contained in Farrell's selective medium were responsible for the inhibitory effects observed.     

Bacteriological investigation—significance of time lapse after death

In cases of sudden unexpected death in infants and children (SUDI), microbiological investigation has been an important part of the autopsy protocol at the University of Oslo for the last 15 years. The purpose of this study was to compare the microbiological findings in samples taken at hospital admittance shortly after death and at autopsy. Blood cultures and cerebrospinal fluid (CSF) were collected both at the hospital and at autopsy; organ samples were additionally collected at autopsy. Hospital samples were collected at a median of 4.5 h (95% confidence interval [CI] 3.25–5) and autopsy samples at a median of 24.25 h (95% CI 22–25.5) after death. The proportion of positive cultures was stable over time; the post mortal time had no influence on bacterial growth. As long as the autopsy is performed within 48 h after death, prior microbiological examination is unnecessary. Blood culture, CSF and lung specimens are the best predictors in our study.     

Molecular investigation and cultivation of camelpox virus in Iran

Camelpox virus (genus Orthopoxvirus, family Poxviridae) is the etiologic agent of camel pox. The clinical manifestations of this virus range from inapparent infection to mild, moderate and, less commonly, severe systemic infection and death. Following an outbreak of camelpox, samples that were collected from camel flocks suspected to have camelpox in Qom Province in central Iran and Khash city, Sistan and Baluchestan Province and South Khorasan Province in eastern Iran were sent to Razi Vaccine and Serum Research Institute in Mashhad. DNA extraction was performed primarily by the phenol-chloroform method, and PCR was carried out using a Bioneer kit. Using the primer pair 5′-AAT-ACA-AGG-AGG-ATC-T-3′ and 5′-CTT-AAC-TTT-TTC-TTT-CTC-3′, the gene sequence encoding the A-type inclusion protein (ATIP) was amplified. The size of the PCR product, specific for camelpox virus, was 881 bp. The PCR product was purified, and to confirm its sequence, it was sent to the reference laboratory. The sequence was subjected to a BLAST search and then phylogenetically analyzed using CLC software. The results showed that all samples were nearly 100 % identical to each other and to strains CMS and M-96. These isolates also had 99 % and 95 % similarity to the CP-1 strain and isolate FIN/T2000, respectively. In Vero cell culture, inoculation with this virus caused a cytopathic effect (CPE), which appeared 2-5 days post-inoculation. Characteristic CPE showing foci of rounded cells, ballooning, giant-cell formation and syncytia with degenerative changes appeared.     

Bacteriological and molecular analysis of rifampin-resistant Mycobacterium tuberculosis strains isolated in Australia

To develop a better understanding of the epidemiology and molecular biology of rifampin-resistant Mycobacterium tuberculosis strains in Australia, 50 clinical isolates (33 rifampin-resistant and 17 rifampin-sensitive strains) cultured between 1990 and 1997 were analyzed by a number of bacteriological and molecular techniques. Examination of the drug resistance profiles of the 33 rifampin-resistant isolates revealed that 91% were resistant to rifampin in combination with resistance to isoniazid, 88% were resistant to rifampin on first isolation, and 81% showed cross-resistance with rifabutin. On the basis of the demographic data provided for the patients infected with the rifampin-resistant strains, 90% of the patients were born overseas. Of these patients, 64% developed clinical symptoms within 5 years of residence in Australia. On a molecular level, analysis of the rpoB gene revealed that 97% of the rifampin-resistant isolates had missense mutations within a conserved region of the gene, and eight types of missense mutations were detected. Of the 31 rifampin-resistant isolates that were typed by restriction fragment length polymorphism (RFLP) analysis, 28 distinct patterns were obtained by RFLP analysis with IS6110, and three clusters of genetically related isolates were identified. All isolates within the clusters were from patients who were born overseas and who had the same country of origin. The results from this study provide an overview of the current situation of rifampin resistance in Australia and can serve as a basis for continued monitoring of drug-resistant M. tuberculosis strains isolated within the country.