heidar rahimi

The genetic diversity of Brucella strains has not been fully understood. To investigate this, the genetic characteristics of 64 isolates of Brucella melitensis from sheep and goats’ milk were studied using random fragment length polymorphism (RFLP) and multiple locus variable-number tandem repeat analysis (MLVA-16) methods developed in Orsay, France (MLVA-16Orsay). The RFLP analysis revealed that all 64 isolates were of biovar one. The MLVA-typing showed that one sample was simultaneously infected with two strains of B. melitensis and the genotype of 65 isolate was analyzed. Four genotypes (47, 42, 43, and 63) were identified using MLVA-8 (panel 1), whereas six genotypes (138, 125, 116, 108, and two unknown genotypes) were identified using MLVA11 (panels 1 and 2A). From the review of MLVA-16 (panels 1, 2A, and 2B), panel 2B showed a very high discriminatory power. Two loci of Bruc04 and Bruc30 from this panel had diversity index values higher than 0.71 and the average diversity index was 0.619. So MLVA-16Orsay 34 showed the genotype indicating a low genetic homogeneity among the isolates. The findings of MLVA genotyping of the isolates suggest that strains of B. melitensis isolated from the milk of small ruminants in Iran are most closely related to the isolates from neighboring countries of the Eastern Mediterranean group. To the best of our knowledge, this is the first study to indicate the potential use of MLVA genotyping for simultaneous detection of specimen contamination using two different B. melitensis biovars.

 Leptospirosis is a zoonotic bacterial disease caused by the genus Leptospira. This disease is observed in human, domestic and wild mammals. Abortion is known as the most important side effect of Leptospira in infected sheep. Molecular tests such as PCR is considered for the early detection of disease which cannot trigger production of species-specific antibodies. This study was designed to detect Leptospira spp. as a cause of abortion in sheep using PCR in Lorestan province, Iran.

 In the current study a total of 150 samples of vaginal swabs were randomly collected from a sheep that had an abortion in some areas of Lorestan province, Iran. The collected samples were accurately investigated to trace DNA of Leptosoira spp. using specific primers.

Based on results of Leptosoira spp. lipL32 gene, 2 positive samples (1.3%) were identified. Hence, it was concluded that there is nosignification relation between abortion rate and Leptospirosis in Lorestan province, Iran. It must be mentioned that due to the zoonotic nature of this bacterium, rapid diagnosis of this disease in livestock can extremely decrease outbreak of this disease in humans.

 Brucellosis is a zoonotic disease which has become endemic in Iran. Contaminated milk with Brucella bacteria is the main way of transmission of this disease in humans. Therefore, the aim of this study was to investigate the prevalence of Brucella spp. and B. abortus in raw milk samples collected from farms belongs to six geographical areas of Lorestan province.

 In the present study, 100 raw milk samples of cows which were less than 4 years, 4 to 6 years and over 6 years old were randomly collected. The isolates were identified by PCR method using specific bcsp31 and IS711 primers for Brucella spp. and B. abortus, respectively.

The results showed that 26 of the samples were infected with Brucella bacteria, of which 19 samples (73%) were B. abortus. Most of the brucellosis infection in cows belonged to cows less than 4 years (31.4%) and 4 to 6 years (31.4%) categories, 11 samples in both groups, so that in cows older than 6 years this rate was 13% (4 samples). The east of the province with 12 samples and the northwest of the province with one sample showed the highest and lowest levels of Brucella infection, respectively. The findings demonstrated that there is a significant difference between the frequency of Brucella contamination in milk in the eastern regions of Lorestan province with other regions (p<0.05). It should be noted that the possibility of transmitting brucellosis to humans through consumption of contaminated raw milk and dairy products in Lorestan province is high.

Prevention, control and eradication of brucellosis in areas where the disease is endemic requires sufficient epidemiological information to apply policies. The present study was conducted with the aim of epidemiological investigation of brucellosis among the ruminant population of Lorestan province. In this cross-sectional descriptive study, all studies related to brucellosis in livestock were analyzed in Lorestan province. The results obtained from this study show that brucellosis has a high prevalence (22%) in three ruminant species (including cows, sheep and goats) of Lorestan province. The highest prevalence of brucellosis in sheep, goat, and cow milk was determined to be 25.6%, 23.5%, and 21.3%, respectively. Brucella abortus is the predominant species in milk obtained from ruminants in Lorestan province. Rev. 1 vaccine strain is excreted to a high extent (7.5%) in sheep and goats' milk. In general, unpasteurized milk is introduced as a threat to public health in Lorestan province. More extensive studies should be conducted, and existing methods of controlling and eradicating brucellosis should be modified.

Brucellosis is an endemic disease with a high prevalence in Iran whose highest frequency is in the western region of the country. Genetic diversity investigation is an important method to determine the epidemiological relationship of Brucella isolates in different geographical areas. Therefore, the present study aimed to investigate the genetic diversity of human Brucella melitensis (B. melitensis) strains using the Multiple Locus Variable-Number Tandem Repeat Analysis (MLVA) Typing method in the west of the country.

In this study, 20 strains of isolated B. melitensis were collected from the human serum samples of suspected Brucellosis in the west of the country and were analyzed by MLVA-16 method.

The results showed that 3 genotype numbers 42, 43 and 47 were identified using MLVA-8 method and using MLVA-11 method genotypes 125, 138 and 111 were recognized. Also, 16 different genotypes were detected from the analysis of the isolates by MLVA-16 method which shows a high degree of polymorphism among the isolates due to the high genetic diversity of the isolates in Panel 2B loci.

The results showed the high genetic diversity of B. melitensis isolates in the west of the country and their genetic relationship with the known strains in the neighboring countries of the Eastern Mediterranean area, as well as the importance of the MLVA method in identifying the source of infection.

The prevalence of Listeria monocytogenes (L. monocytogene) in milk and dairy products, the high complications and damage associated with zoonotic Listeriosis have led to this bacterium being considered as a risky infection for public health.

In the present descriptive and cross-sectional study, to investigate the prevalence of L. monocytogene, 100 samples of raw milk obtained from industrial farms in Lorestan province in winter and spring of 2019-2020 were collected and 16SrRNA and hlyA genes were detected using PCR reaction to identify Listeria genus and L. monocytogene species, respectively.

Based on the observed results, three samples (3%) were positive for Listeria genus, while no report of L. monocytogens species was observed.

The results of this study did not show evidence of the presence of L. monocytogenes in raw cow milk, which indicates the sanitation and desirable nutritional conditions in industrial farms. Therefore, due to the presence of Listeria (other species of Listeria) in raw milk, if you consume raw and unpasteurized milk, the risk of human infection with listeriosis should not be ignored.

Staphylococcus aureus is a significant pathogen that can colonize the nares of different animals, causing a wide range of infections in various hosts. We intended to determine the prevalence of S. aureus in the nasal cavity of healthy ruminants and also to investigate the presence of antibiotic resistance genes. In the present study, healthy cattle (n = 79), sheep (n = 78) and goats (n = 44) were screened for nasal carriage of S. aureus by the Polymerase Chain Reaction (PCR). Staphylococcus aureus isolates were further assessed for the presence of blaZ (encoding penicillin resistance), mecA (encoding methicillin resistance), tetK and tetM (encoding tetracycline resistance), and ermA and ermC (encoding macrolide-lincosamide-streptogramin B resistance) genes. The proportion of S. aureus-positive nasal swabs from cattle, sheep and goats were four (5.06%), 11 (14.1%) and 11 isolates (25%), respectively. The blaZ gene was detected in 20 out of 26 S. aureus isolates (76.9%), including four cattle (100%), nine sheep (81.8%) and seven goats (63.6%). Two of the four cattle isolates possessing the blaZ gene also had the tetK gene. Of the nine sheep isolates harboring the blaZ gene, one possessed the mecA and tetK genes together. Of the seven goat isolates with blaZ gene, one harbored the tetM gene. None of the S. aureus isolates were positive for the ermA and ermC genes. In contrast to cattle, S. aureus is frequently present in the nose of sheep and goats, which may represent the primary reservoir of S. aureus in small ruminant flocks. This study also showed that nasal isolates of S. aureus from healthy ruminants might be a potential reservoir of antimicrobial-resistance.