Molecular detection of Leptospira spp. in the urine of cattle in northern Iran

Leptospirosis is a zoonosis of worldwide distribution, caused by Leptospira interrogans and is considered as an emerging global public health problem. Transmission usually results from direct or indirect exposure to the urine or other body fluids of leptospiruric animals which may become a source of infection for human or other animals. Having a humid climate with plenty of annual rainfall, Guilan province is a suitable environment for maintaining Leptospira spp. Hence, early detection of Leptospira spp. in the host prompts control and protection, and the polymerase chain reaction [PCR] is a suitable method. The present report aimed to demonstrate the PCR analysis of bovine urine for detection of leptospiral DNA. A total of 98 urine samples were randomly collected from cattle bladder in Rasht abattoir of Iran and the presence of leptospiral DNA was assayed by PCR amplification of rrs [16S rRNA] gene and the results confirmed by nested PCR. Out of 98 urine samples in 42 samples leptospires DNA was identified with the frequency of 43%. The high presence of the organism in the urine of carriers is a serious threat to the dairy farms and to the public health which requires an effective control measure in the north provinces of Iran

prevalence of coronavirus in fecal samples of neonatal calf diarrhea using electron microscopic examination

Neonatal calf diarrhea [NCD], also known as calf scours, is caused by viruses, bacteria, and parasites. Coronavirus is one of the important causes of NCD syndrome. Electron microcopy has been used for demonstration of viruses in fecal samples of diarrheic calves since 1969. The aim of this study was to determine the prevalence of coronavirus in fecal samples of neonatal calf diarrhea using electron microcopy examination of fecal samples. For the purpose of this study, a total of 100 cases [under 2 months of age] of diarrheic calves from 25 commercial farms in four districts of East Azerbaijan province of Iran were used. Fresh Fecal samples using sterile swab were collected from every calf with clinical diarrhea. All samples were transferred into a sterile container and then were sent to the laboratory to be kept in -20oC freezer until examination. Electron microscopic examination was applied to all fecal samples. Chi-square test was used to analyze the data. According to the results of this study, coronavirus was present in 15% of cases and a significant difference was found between the prevalence rate and the seasons [p<0.05]. The highest prevalence was recorded in winter [28%] and the least prevalence was seen in summer [4%]. There was not any significant difference in both age groups and different districts according to the prevalence rate of infection. Neonatal calf diarrhea is a multi-etiological syndrome. Among the viral diarrhea, bovine coronavirus is one of the major causes of this syndrome. For detection of coronavirus in feces, electron microscope examination is a gold standard diagnostic technique. It seems that coronavirus can be considered as one of the important etiologies of neonatal calf diarrhea in east Azerbaijan of Iran

Serological and bacteriological study of leptospirosis in dairy herds and feedlot in Tehran suburbs

Leptospirosis is a worldwide zoonosis caused by Leptospira interrogans. Leptospirosis results in decreased milk production, abortion, stillbirth, infertility and mortality, which causes financial loss in the cattle industry. The aim of this research was to perform a serological and bacteriological study of leptospirosis in 6 industrial dairy herds and 3 feedlots with previous records of leptospirosis in Tehran suburbs in 2011-2012. For the purpose of this study, 408 blood samples from dairy cattle and 154 blood samples from feedlots were collected using sterile 10ml venoject vacutainers from tail vein. Two months later, 118 urine samples were collected from 20% of the two groups of serological negative and positive animals. All serum samples were serologically tested by microscopic agglutination test [MAT], a standard method for serological diagnosis of leptospirosis. The serum samples were tested for antibodies against five live antigens of Leptospira interrogans serovars: Pomona, Grippotyphosa, Hardjo, Icterohaemorrhagiae and Canicola. Urine samples were used for bacteriological isolation of Leptospira spp. Serological results showed that 228 [40.6%] of animals had a positive reaction against one or more serovars. The most prevalent Leptospira serovars was Pomona 118 [40.3%] and the least prevalent was Canicola 4 [1.4%]. The most prevalent titer was 1:100, and the highest titer was 1:1600. Also the most seropositive cases were observed in 3 to 4-year-old cows. Bacteriological results revealed that in 11 [9.3%] urine samples Leptospira spp. were isolated, all taken from one feedlot farm. According to the history taken from each farm, the main risk factors were the presence of rodents and low hygienic conditions of the farms. The results of this study revealed that cows could have a major role in maintaining Pomona, Grippotyphosa and Hardjo serovars; indeed, they are a potential zoonotic risk to slaughter house workers, meat inspectors, milkers and farmers

Serodiagnosis and molecular survey on leptospiral abortions in the dairy cattle of Tabriz

Leptospirosis is an important infectious disease of animals and humans caused by the pathogenic leptospires which are classified into one species of Leptospira interrogans containing over 212 serovars. This study was conducted to determine the prevalence of Leptospira-induced abortions in Tabriz [north-west of Iran] dairy herds and to determine the pathogenic Leptospira serovars responsible. From May 2008 through August 2010, 16 [21.05%] of 76 submissions [fetuses and placentas] to the Large Animal Clinic of the Veterinary Faculty at the University of Tabriz were diagnosed as positive to L. interrogans serovars by PCR

In contrast, only 9 [11.85%] of 76 dam's sera were diagnosed as positive to leptospirosis by the microscopic agglutination test [MAT]

Two out of 9 animals were seropositive to serovar pomona, one animal to serovar icterohaemorrhagiae, two animals to canicula, three animals to both pomona and grippotyphosa, and one animal to the both canicula and grippotyphos. Moreover, the prevalence of Leptospira-induced abortions was high in the aged cows and advanced pregnancies [7-9 months]

However statistical difference was not observed among these groups or different periods of pregnancy. In conclusion, serovar pomona induced abortions were determined to be more common leptospiral abortions in cattle in Tabriz and combination of PCR protocol with the MAT test would be more effective than the single test for etiological diagnosis of bovine abortions?