Prevalent Serovars Research Articles

Leptospira infections in freshwater fish in Morogoro Tanzania: a hidden public health threat

Leptospirosis caused by spirochete bacterium of genus Leptospira affects humans and animals worldwide. Rodents are major reservoirs of leptospires whereas wetland and aquatic migratory birds also carry and transmit leptospires. Leptospirosis studies in fish are lacking in African countries despite favourable environment and abundant reservoirs, which can spread leptospires into aquatic habitats and infect fish. The objectives of this study were to determine presence of Leptospira in fish; the prevalent Leptospira serovars and whether are related to serovars reported in animals; and to ascertain potential public health risk. Live tilapia, catfish and eel fish (n = 48) were caught in Mindu Dam in Morogoro Municipality in eastern Tanzania. Blood sample was collected using syringes and needles to obtain serum for serological detection of leptospirosis using gold standard microagglutination test utilizing local and reference Leptospira serovars Sokoine, Kenya, Pomona and Hebdomadis. Twenty-six fish (54.2%) were positive for serovar Kenya (29.2%) and Sokoine (25%). Leptospira prevalence was high in both catfish (58.3%) and tilapia fish (47.8%). Thus, different fish types are infected with Leptospira found in animals. Fish could be source of Leptospira infection to humans since tilapia and catfish are the common fish type widely consumed in Tanzania. Further study covering lakes, rivers and dams is required to better understand the prevalence of Leptospira in fish and actual public health threats.

Seroprevalence of bovine leptospiral antibodies by microscopic agglutination test in Southeast of Iran

To evaluate serological findings of bovine leptospirosis which is a zoonotic disease with worldwide distribution caused by Leptospira interrogans. One hundred and sixty seven sera were collected from 9 commercial dairy herds in jiroft suburbs, from July to October 2011. Microscopic agglutination test (MAT) was used to evaluates serological findings of bovine leptospirosis in Jiroft suburb dairy farms, Kerman province, Iran. Antibodies were found by MAT at least against one serovar of Leptospira interrogans in 29 samples (17.36%) among 167 sera at a dilution 1:100 or higher, and Leptospira pomona was the most prevalent serovar. Positive titers against more than one serovar were detected in 6 sera of the positive samples. This study is the first report of leptospirosis in Southeast Iran and showed that Leptospira pomona was the most and Leptospira icterohaemorrhagiae the least prevalent serovars in Southeast Iran.

Trends in the epidemiology of pandemic and non-pandemic strains of Vibrio parahaemolyticus isolated from diarrheal patients in Kolkata, India.

A total of 178 strains of V. parahaemolyticus isolated from 13,607 acute diarrheal patients admitted in the Infectious Diseases Hospital, Kolkata has been examined for serovar prevalence, antimicrobial susceptibility and genetic traits with reference to virulence, and clonal lineages. Clinical symptoms and stool characteristics of V. parahaemolyticus infected patients were analyzed for their specific traits. The frequency of pandemic strains was 68%, as confirmed by group-specific PCR (GS-PCR). However, the prevalence of non-pandemic strains was comparatively low (32%). Serovars O3:K6 (19.7%), O1:K25 (18.5%), O1:KUT (11.2%) were more commonly found and other serovars such as O3:KUT (6.7%), O4:K8 (6.7%), and O2:K3 (4.5%) were newly detected in this region. The virulence gene tdh was most frequently detected in GS-PCR positive strains. There was no association between strain features and stool characteristics or clinical outcomes with reference to serovar, pandemic/non-pandemic or virulence profiles. Ampicillin and streptomycin resistance was constant throughout the study period and the MIC of ampicillin among selected strains ranged from 24 to >256 µg/ml. Susceptibility of these strains to ampicillin increased several fold in the presence of carbonyl cyanide-m-chlorophenyldrazone. The newly reported ESBL encoding gene from VPA0477 was found in all the strains, including the susceptible ones for ampicillin. However, none of the strains exhibited the β-lactamase as a phenotypic marker. In the analysis of pulsed-field gel electrophoresis (PFGE), the pandemic strains formed two different clades, with one containing the newly emerged pandemic strains in this region.

Salmonella Enterica Prevalence in Finishing Pigs at Slaughter Plants in Northern Italy.

Finishing pigs carrying Salmonella enterica are believed to be the main source of carcass contamination at the beginning of slaughtering. The aim of this study was to assess the S. enterica carrier status of finishing pigs at herd level by sampling pooled faeces on farm and mesenteric lymph nodes at slaughter in the North East of Italy. Environmental faecal samples belonging to 30 batches of pigs were collected on farm. At slaughter, mesenteric lymph nodes were collected from five randomly selected pigs per batch. S. enterica was isolated from 16 lymph nodes out of 150 (10.6%) and from seven out of 30 (23.3%) faecal samples. Four batches (13.3%) were positive to S. enterica both in lymph nodes and in faeces. The number of batches positive to S. enterica either in lymph nodes or in faeces was 13 out of 30 (43.3%). The most prevalent serovars from lymph nodes were S. Derby (25.0%) and S. Typhimurium monophasic variant 1, 4,[5],12:i:- (18.6%), which were also isolated from faecal material (14.3 and 42.8% respectively). Contaminated faecal material or lymph nodes could be a primary source of carcass contamination at slaughter during evisceration. S. enterica contamination is widespread on pig farms and carrier pigs pass undetected the inspection visits at slaughter, entering the food chain. Therefore, in order to control S. enterica in pigs, the need to quantify possible risk factors at slaughter and develop effective management strategies on farm is of paramount importance to ensure food safety.

Emergence and clonal dissemination of Salmonella enterica serovar Enteritidis causing salmonellosis in Mauritius.

For decades, Salmonella enterica serovar Enteritidis has been among the most prevalent serovars reported worldwide. However, it was rarely encountered in Mauritius until 2007; since then the number of non-typhoidal Salmonella serogroup O:9 (including serovar Enteritidis) increased. A study was conducted to investigate the genetic relatedness between S. Enteritidis isolates recovered in Mauritius from food and clinical specimens (stool, blood, and exudate). Forty-seven isolates of S. Enteritidis obtained in 2009 from human stools, blood cultures and exudates, and from food specimens were characterized by antimicrobial susceptibility testing and Multiple-Locus Variable-number tandem repeat Analysis (MLVA). With the exception of a single isolate which demonstrated intermediate susceptibility to streptomycin, all isolates were pansusceptible to the 14 antimicrobials tested. Thirty seven out of the 47 isolates (78.7%) exhibited an indistinguishable MLVA profile which included isolates from ready-to-eat food products, chicken, and human clinical isolates from stool, blood and exudate. The presence of highly related strains in both humans and raw chicken, and the failure to isolate the serovar from other foods, suggests that poultry is the main reservoir of S. Enteritidis in Mauritius and that the majority of human cases are associated with chicken consumption which originated from one major producer. Stool isolates were indistinguishable or closely related to blood and exudate isolates, indicating that, besides gastroenteritis, the same strain caused invasive infections. Control of S.Enteritidis by poultry breeders would lower the financial burden associated with morbidity in humans caused by this organism in Mauritius.

Integrative Analysis of Salmonellosis in Israel Reveals Association of Salmonella enterica Serovar 9,12:l,v:− with Extraintestinal Infections, Dissemination of Endemic S. enterica Serovar Typhimurium DT104 Biotypes, and Severe Underreporting of Outbreaks

Salmonella enterica is the leading etiologic agent of bacterial food-borne outbreaks worldwide. This ubiquitous species contains more than 2,600 serovars that may differ in their host specificity, clinical manifestations, and epidemiology. To characterize salmonellosis epidemiology in Israel and to study the association of nontyphoidal Salmonella (NTS) serovars with invasive infections, 48,345 Salmonella cases reported and serotyped at the National Salmonella Reference Center between 1995 and 2012 were analyzed. A quasi-Poisson regression was used to identify irregular clusters of illness, and pulsed-field gel electrophoresis in conjunction with whole-genome sequencing was applied to molecularly characterize strains of interest. Three hundred twenty-nine human salmonellosis clusters were identified, representing an annual average of 23 (95% confidence interval [CI], 20 to 26) potential outbreaks. We show that the previously unsequenced S. enterica serovar 9,12:l,v:- belongs to the B clade of Salmonella enterica subspecies enterica, and we show its frequent association with extraintestinal infections, compared to other NTS serovars. Furthermore, we identified the dissemination of two prevalent Salmonella enterica serovar Typhimurium DT104 clones in Israel, which are genetically distinct from other global DT104 isolates. Accumulatively, these findings indicate a severe underreporting of Salmonella outbreaks in Israel and provide insights into the epidemiology and genomics of prevalent serovars, responsible for recurring illness.

Seroepidemiología de la leptospirosis en bovinos con trastornos reproductivos en el municipio de Montería, Colombia

Se realizó un estudio descriptivo para determinar la prevalencia de leptospirosis en bovinos con trastornos reproductivos de zonas rurales de Montería, Colombia. Se colectaron muestras de suero de 26 toros y 137 vacas procedentes de 28 fincas con antecedentes de problemas reproductivos, los cuales fueron analizados mediante técnica de microaglutinación (MAT) para detección de anticuerpos contra Leptospira. Se utilizaron antígenos de los serovares pomona, hardjo, canicola, grippotyphosa e icterohaemorrhagiae. El 41 % de los sueros fue positivo a Leptospira a punto de corte 1:20. Los serovares prevalentes fueron grippotyphosa (29,85 %) hardjo e icterohaemorrhagiae (20,8 y 16,41 %). Se realizó una prueba de chi cuadrado (χ2) para establecer relación entre la seropositividad a Leptospira y las variables de sexo, edad, antecedentes de abortos y repetición de servicios de cada animal, así como zona de muestreo y sistema de producción de las fincas. La seropositividad a Leptospira fue de 26,86 % y 29,85 % en los grupos de edad de 3-4 años y de 5-6 años, y del 43,2 % en bovinos ≥ 7 años. La seroprevalencia en vacas abortadas y no abortadas fue similar (35 y 34 %); asimismo, la seropositividad en vacas con y sin repeticiones de servicio fue de 34 y 35 %, respectivamente. El 41,7 % de las fincas con sistema de producción de carne y el 58,2 % con doble propósito fueron positivas a diferentes serovares. Sin embargo, no se encontró dependencia entre la seropositividad a Leptospira y las variables mencionadas (p > 0,05). Los resultados indican una alta seroprevalencia de leptospirosis en bovinos con trastornos reproductivos del municipio de Montería.

Antimicrobial Susceptibility and Serovars of Salmonella Circulating in Commercial Poultry Carcasses and Poultry Products in Brazil

Antimicrobial resistance was evaluated for 12,582 strains of Salmonella isolated by public and private laboratories from commercial poultry carcasses and poultry products from different regions in Brazil between 2007 and 2011. These isolates were submitted unsolicited to the National Reference Laboratory for Bacterial Enteroinfections, Oswaldo Cruz Institute, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil, for conclusive antigenic characterization. The prevalent Salmonella enterica serogroups were O:4 (B) (28.9%), O:9 (D1) (22.3%), O:21 (L) (15.9%), and O:7 (C1) (14.3%); the most prevalent serovars were Enteritidis, Minnesota, Typhimurium, Schwarzengrund, and Mbandaka. The antimicrobial susceptibility profiles of 1,234 strains indicated that 54.5% were resistant to up to eight antimicrobial drugs. Multidrug resistance (three or more classes) was observed in 16.4% of the strains, with 190 distinct patterns. The results showed increased resistance to ampicillin (12.4 to 18.9%), tetracycline (≈ 15.2 to ≈ 18.9%), and gentamicin (f7.0 to ≈ 9.6%) during the study period. Decreased resistance to nitrofurans (61.9 to 9.2%), quinolones (44.4 to 15.5%), and folate inhibitors (11.7 to 7.2%) was observed. Resistance to third-generation cephalosporins was detected in 5.5% of the strains throughout the study period; resistance to fluoroquinolones has been observed in 0.3% of the strains since 2009. These findings highlight the importance of surveillance along the food chain for detection of altered patterns among foodborne zoonotic bacteria that are important to public health.

Prevalence, molecular identification and antimicrobial resistance profile of Salmonella serovars isolated from retail beef products in Mansoura, Egypt

The present study was undertaken to determine the prevalence of Salmonella in 270 raw meat samples (90 each of fresh beef, ground beef, and beef burger) purchased on nine occasions from various supermarkets and butchers' shops in Mansoura city, Egypt. Using conventional biochemical identification, Salmonella species were recovered from 23.3% (21/90), 20% (18/90), and 12.2% (11/90) of fresh beef, ground beef and beef burger samples, respectively with an overall prevalence of 18.5% (50/270) among all the meat products examined. Higher prevalence were obtained based on molecular identification, by detecting gyrB and invA genes, which verified the presence of Salmonella species in 30.0% (27/90), 26.7% (24/90), and 16.7% (15/90) of fresh beef, ground beef, and beef burger samples, respectively with an overall prevalence of 24.4% (66/270) among all the meat products tested. Of the 2635 presumptive colonies tested, 228 were biochemically identified as Salmonella, while 272 were molecularly identified as Salmonella, which were all positive for the enterotoxin (stn) virulent gene. Of the 272 serologically tested strains, 266 were serologically identified into six Salmonella serovars, while 6 strains were untypable. Salmonella Typhimurium and Salmonella Enteritidis were the most prevalent serovars with an incidence of 38.2% (104/272) and 34.6% (94/272), respectively. The other four serovars identified were Salmonella Haifa, Salmonella Muenster, Salmonella Virchow, and Salmonella Anatum were detected at lower prevalences of 11% (30/272), 7.4% (20/272), 4% (11/272) and 2.6% (7/272), respectively. Interestingly, the antimicrobial susceptibility testing indicated that all of the 100 Salmonella serovars tested were multidrug resistant (resistant to three or more antibiotics). Our findings demonstrated that the retail beef products tested were widely contaminated with multidrug-resistant Salmonella and such contamination may constitute a major public health concern.

Decline of Salmonella Enteritidis in poultry

Purpose – The aim of this study was to serotype strains of Salmonella isolated from poultry and raw poultry meat from 2006 to 2010 and to correlate the results with data from the Health Department of Parana State. Design/methodology/approach – A total of 1.165 Salmonella spp. strains isolated from commercial broiler breeders and laying hens (cloacal swabs, dragging swabs and faeces) and from one-day-old chicks (liver, spleen and cecum) and 310 strains isolated from raw chicken meat were serotyped between 2006 and 2010. Findings – The results showed a decline in the isolation of S. Enteritidis (SE) of poultry and chicken meat in the studied period. The most prevalent serovar isolated from raw chicken meat was Minnesota (n=73; 23.02%), followed by Mbandaka (n=33; 10.41%) and Enteritidis (n=30; 9.46%). The decrease in frequency of isolation of SE may be related to the broiler breeder hens vaccination and to the National Program for the Reduction of Pathogens of the Brazilian Agriculture Ministry and Food Supply, established in 2003. Originality/value – The results reinforce the importance of improving bio-safety programs for the control and eradication of Salmonella spp. in the poultry industry.

Molecular characterization, serotyping, and antibiotic susceptibility profile of Leptospira interrogans serovar Copenhageni isolates from Brazil

Leptospira interrogans serogroup Icterohaemorrhagiae is the major serogroup infecting humans worldwide, and rodents and dogs are the most significant transmission sources in urban environments. Knowledge of the prevalent serovars and their maintenance hosts is essential to understand the epidemiology of leptospirosis. In this study, 20 Leptospira isolates were evaluated by pulsed-field gel electrophoresis (PFGE), variable number tandem-repeat analysis (VNTR), serotyping, and determination of antimicrobial resistance profile. Isolates, originated from bovine, canine, human, and rodent sources, were characterized by microscopic agglutination test with polyclonal and monoclonal antibodies and were identified as L. interrogans serogroup Icterohaemorrhagiae serovar Copenhageni. MICs of antimicrobials often used in veterinary medicine were determined by broth microdilution test. Most of tested antibiotics were effective against isolates, including penicillin, ampicillin, and ceftiofur. Higher MIC variability was observed for fluoroquinolones and neomycin; all isolates were resistant to trimethoprim/sulfamethoxazole and sulphadimethoxine. Isolates were genotyped by PFGE and VNTR; both techniques were unable to discriminate between serovars Copenhageni and Icterohaemorrhagiae, as expected. PFGE clustered all isolates in 1 pulsotype, indicating that these serovars can be transmitted between species and that bovine, rodent, and dogs can maintain them in the environment endangering the human population.

P1.003 Experimental Study on Pathogenic Diversity of Different Chlamydia Trachomatis Serovars in Mouse Genital Infection

Background Chlamydia trachomatis infection increases above gonorrhoea and syphilis, ranking first among the STDs. Molecular epidemiological researches have shown the predominant genotypes vary between regions, periods and population subgroups. However,...

Prevalence, characterization and antimicrobial susceptibility of Salmonella enterica and Yersinia enterocolitica in pigs at slaughter in Italy

In 2005–2008, 1152 samples (451 faecal samples, 451 carcass swabs and 250 tonsils) were collected from 451 finishing pigs slaughtered in three abattoirs of northern Italy. In two abattoirs, 34 scalding water samples were collected. The aim of this study was to investigate the faecal and palatine tonsil carriage rate of Salmonella enterica and Yersinia enterocolitica in pigs at slaughter and the degree of carcass contamination by these bacteria. Typing of the isolates, virulence characterization and antimicrobial testing were also performed.S. enterica was isolated from 21.5% of the faecal samples, 10.9% of the carcasses and 10.4% of the tonsils, but not from scalding water. Nineteen different serovars were identified among 172 S. enterica isolates. The prevalent serovars were Derby (41.3%), Rissen (12.2%), Typhimurium (11%), 4,[5],12:i:— (8.7%) and Give (4.1%). S. enterica ser. Typhimurium and S. enterica ser. 4,[5],12:i:— isolates were phage-typed and PT DT120 was the most common (23.5%). Y. enterocolitica was detected in 17.1% of the faecal samples, 2.4% of the carcasses, 10.8% of the tonsils and 11.8% of the scalding water samples. A total of 119 isolates were found, four of them in water. Of the 115 Y. enterocolitica isolates of pig origin, 24 (20.9%) were 4/O:3 and 4 (3.5%) were 2/O:9. Y. enterocolitica 4/O:3 represented 85.7% of the pathogenic isolates found in all types of samples and 100% of those found in tonsils. In 4/O:3 isolates the most common virulence-associated genes were ystA (100%), inv (95.8%), ail (87.5%) and yadA (54.2%). In 2/O:9 isolates the prevalent genes were ail (100%), inv (100%) and ystA (100%), followed by ystB (25.0%). The majority (75.7%) of Y. enterocolitica isolates was biotype 1A, belonging to 13 serotypes (O:3; O:5; O:4,32-4,33; O:6,30-6,31; O:7,8-8; O:7,8-8-8,19; O:7,13; O:8; O:9; O:13; O:16-16,29; O:41,42-41,43; O:52). The most common virulence genes in 1A isolates were inv (95.4%) and ystB (72.4%).The antimicrobial resistance test showed that all Salmonella isolates were susceptible to cefotaxime, ciprofloxacin, cefalothin, gentamicin and enrofloxacin. Resistances to tetracycline (56%), sulphonamide compounds (42%) and streptomycin (34%) were the most common. All Y. enterocolitica isolates were susceptible to ciprofloxacin, ceftazidime, cefotaxime, chloramphenicol, enrofloxacin, gentamicin, kanamicin and neomycin. Most isolates were resistant to cefalothin (92%) and ampicillin (89%).Apparently, carcass contamination by S. enterica and Y. enterocolitica was more likely attributable to cross-contamination than to self-contamination, suggesting that good hygienic measures and slaughtering procedures can control transmission of these pathogens to pork meat.

Distribution of Leptospira Serogroups in Dogs from Berlin, Germany

Leptospirosis is a bacterial zoonosis in which dogs can act as a reservoir for human infection. The annual vaccination of dogs can prevent leptospirosis caused by serovars included in the vaccine. To date, all available vaccines in Germany include only the serovars Icterohaemorrhagiae and Canicola, the most commonly found serovars prior to the introduction of the leptospirosis vaccines. Yet, the involvement of additional serovars in the clinical presentation of leptospirosis in dogs has been described. The objective of this sero-epidemiological study was to examine the different Leptospira serovars currently circulating in a population of dogs suspicious for leptospirosis from Berlin. In 329 dogs presenting at the Small Animal Clinic in Berlin, the predominant serogroup was Australis (24%), followed by Grippotyphosa (20%) and Pomona (9%). A total of 18% of the dogs were diagnosed with clinical leptospirosis; here the most prevalent serogroups were also Australis (28%), Grippotyphosa (18%), and Pomona (14%). The serovar prevalence data presented here confirm that a change of pattern of infecting Leptospira serovars in dogs has taken place in Berlin. This data corresponds to further sero-epidemiological studies from other regions in Germany. To ensure human and canine health, available vaccines should be adapted to include the most important circulating serovars.

Colonization and Internalization of Salmonella enterica in Tomato Plants

The consumption of fresh tomatoes has been linked to numerous food-borne outbreaks involving various serovars of Salmonella enterica. Recent advances in our understanding of plant-microbe interactions have shown that human enteric pathogenic bacteria, including S. enterica, are adapted to survive in the plant environment. In this study, tomato plants (Solanum lycopersicum cv. Micro-Tom) grown in sandy loam soil from Virginia's eastern shore (VES) were inoculated with S. enterica serovars to evaluate plausible internalization routes and to determine if there is any niche fitness for certain serovars. Both infested soil and contaminated blossoms can lead to low internal levels of fruit contamination with Salmonella. Salmonella serovars demonstrated a great ability to survive in environments under tomato cultivation, not only in soil but also on different parts of the tomato plant. Of the five serovars investigated, Salmonella enterica serovars Newport and Javiana were dominant in sandy loam soil, while Salmonella enterica serovars Montevideo and Newport were more prevalent on leaves and blossoms. It was also observed that Salmonella enterica serovar Typhimurium had a poor rate of survival in all the plant parts examined here, suggesting that postharvest contamination routes are more likely in S. Typhimurium contamination of tomato fruit. Conversely, S. Newport was the most prevalent serovar recovered in both the tomato rhizosphere and phyllosphere. Plants that were recently transplanted (within 3 days) had an increase in observable internalized bacteria, suggesting that plants were more susceptible to internalization right after transplant. These findings suggest that the particular Salmonella serovar and the growth stage of the plant were important factors for internalization through the root system.

Genetic Types, Gene Repertoire, and Evolution of Isolates of the Salmonella enterica Serovar 4,5,12:i:− Spanish Clone Assigned to Different Phage Types

Salmonella enterica subsp. enterica 4,[5],12:i:- is one of the most prevalent serovars associated with human infections worldwide. Two multidrug-resistant clones, designated Spanish and European clones, are recognized as having importance for public health and are subject to control measures in the European Union. In this study, 23 clinical isolates belonging to the Spanish clone were characterized by multilocus sequence typing, multiple-locus variable number tandem repeat analysis (MLVA), PCR amplification and sequencing, and a DNA microarray targeting 263 genes, in order to provide new insights into their origins and further evolution. The derived data were compared with information available from other studies for S. 4,[5],12:i:- isolates of both the Spanish and the European clones, to identify differential molecular markers which could be potentially used as surveillance tools in the control of dissemination of this serovar. The isolates analyzed were assigned to sequence type 19 and to 17 MLVA patterns, with 3-13-16-NA-311 being the most prevalent. Highly similar virulence, metabolic, and prophage-associated gene profiles were identified, but DNA mobility markers distinguished five genotypes. Two types of deletions, caused by insertion of IS26, presumably donated by pUO-STmR/RV1-like plasmids typically found in the Spanish clone, affected the fljAB operon and surrounding DNA. The Spanish and European clones differ in sequence type, MLVA patterns, gene repertoire, and fljAB deletion type. The observed variability supports an independent evolution of the two successful monophasic clones from different Salmonella enterica serovar Typhimurium ancestors and can be taken into consideration for epidemiological surveillance.

Canine leptospirosis – a seroprevalence study from Kerala, India

Aim: To study the seroprevalence of leptospirosis in dogs in Kerala and to identify the most prevalent serovar. Materials and Methods: A total of 205 sera collected from dogs were screened for the presence of antibodies against leptospirosis by Microscopic Agglutination Test (MAT). Results: A seroprevalence rate of 71.12 per cent was observed. Leptospira interrogans serovar Autumnalis was found to be the most prevalent serovar followed by Australis, Pomona, Canicola, Pyrogenes, Icterohaemorrhagiae, Javanica and Patoc. Conclusions: The results revealed the high prevalence of anti leptospiral antibodies in dogs in Kerala. The emergence of serovars other than the vaccinal serovars necessitates the incorporation of these in the vaccines because the immunity against leptospirosis is serovar specific. Key words: canine leptospirosis, MAT, seroprevalence

Seroepidemiological detection of antibodies against Leptospira spp using microscopic agglutination test in Urmia cows and sheep

The study was designed to determine the level of incidence, titer and various serovars of leptospira in 203 cows and 166 sheep at Urmia abattoir in 2011. Blood samples were collected during the slaughter of animals and sera were separated to evaluate the serological reaction to Leptospira spp by Microscopic Agglutination Test (MAT) using live antigens representing Leptospira interrogans serogroups: pomona, grippotyphosa, canicola, hardjo, icterrohaemoragiae, and ballum. Overall, 36% of cows and 19.3% of sheep including 33.8% of bulls, 40.5% of female cows, 18.3% of rams and 25% of ewes had a positive reaction to at least one of the leptospira serovars. The most prevalent serovars in cows were pomona (22.7%), grippotyphosa (13.8%), and hardjo (8.4%), and in sheep were grippotyphosa (66.7%), pomona (26.2%) and canicola (7.1%). Other serovars were not detected in cows and sheep. The most prevalent serological titers of 1:100 and 1:200 in cows was 18.2% and 26.6%, and for sheep were 13.5% and 8%, respectively, and of 1:400 in sheep was 2.3%. Cows with a positive reaction to one, two and three serovars were 28.6%, 5.9%, and 1.5% and sheep positive to one and two serovars were 13.3% and 6%, respectively. Age comparison in seropositive cows and sheep showed a significantly increased infection (p<0.05) from young to adult ruminants, while no differences were seen regarding gender. The main mixed serovars were between grippotyphosa/pomona, grippotyphosa/canicola and canicola/pomona. The gender comparison of the serovars' distribution revealed that the pomona and grippotyphosa were predominant among other leptospiral serovars in cows and sheep, respectively. In conclusion, the rate of leptospirosis in Urmia cows was about 2 fold in sheep. The most current serovars in cows and sheep were pomona and grippotyphosa, respectively. The majority of animals was infected with one serovar, but polyserovars, are also possible. The highest titer (1:200) was observed in cows and 1:400 in sheep. There was no gender difference, but age was significant between cows and sheep. Finally, leptospirosis as a zoonotic disease must be seriously considered in Urmia cows rather than in sheep, and therefore, a serious effort must be made to reduce the rate of serological infection and the risk of public health, as well.

Serological Evidence of Exposure toLeptospiraspp. in Veterinary Students and Other University Students in Trinidad and Tobago

The study compared the serological evidence of leptospirosis in 212 students in four schools (veterinary, dental, advanced nursing education and pharmacy) of the University of the West Indies (UWI), by testing for IgG immunoglobulins to Leptospira spp. using the enzyme-linked immunosorbent assay (ELISA) and the microscopic agglutination test (MAT). Overall, of 212 students tested by the ELISA, 12 (5.7%) and 31 (14.6%) were positive and borderline, respectively. Amongst the 113 veterinary students 11 (9.7%) and 19 (16.8%) were seropositive and borderline respectively compared with nonveterinary students with corresponding values of 1 (1.0%) and 12 (12.1%). The frequency of serological evidence of leptospirosis by the ELISA was statistically significantly (P < 0.05; χ 2) higher in veterinary students, 26.5% (30 of 113) than in nonveterinary students, 13.1% (13 of 99). By the MAT, the seropositivity for leptospirosis was similar for veterinary students, 7.1% (8 of 113) and nonveterinary students, 7.1% (7 of 99). For veterinary students, the prevalent infecting serovar was Icterohaemorrhagiae Copenhageni while amongst nonveterinary students, the prevalent serovar was Australis Rachmati. Being a veterinary student was the only risk factor that was significantly associated with Leptospira infection indicating that veterinary students need to be cognizant and to practise preventive measures for leptospirosis.

Comparative genomics of Salmonella enterica serovars Derby and Mbandaka, two prevalent serovars associated with different livestock species in the UK

BackgroundDespite the frequent isolation of Salmonella enterica sub. enterica serovars Derby and Mbandaka from livestock in the UK and USA little is known about the biological processes maintaining their prevalence. Statistics for Salmonella isolations from livestock production in the UK show that S. Derby is most commonly associated with pigs and turkeys and S. Mbandaka with cattle and chickens. Here we compare the first sequenced genomes of S. Derby and S. Mbandaka as a basis for further analysis of the potential host adaptations that contribute to their distinct host species distributions.ResultsComparative functional genomics using the RAST annotation system showed that predominantly mechanisms that relate to metabolite utilisation, in vivo and ex vivo persistence and pathogenesis distinguish S. Derby from S. Mbandaka. Alignment of the genome nucleotide sequences of S. Derby D1 and D2 and S. Mbandaka M1 and M2 with Salmonella pathogenicity islands (SPI) identified unique complements of genes associated with host adaptation. We also describe a new genomic island with a putative role in pathogenesis, SPI-23. SPI-23 is present in several S. enterica serovars, including S. Agona, S. Dublin and S. Gallinarum, it is absent in its entirety from S. Mbandaka.ConclusionsWe discovered a new 37 Kb genomic island, SPI-23, in the chromosome sequence of S. Derby, encoding 42 ORFS, ten of which are putative TTSS effector proteins. We infer from full-genome synonymous SNP analysis that these two serovars diverged, between 182kya and 625kya coinciding with the divergence of domestic pigs. The differences between the genomes of these serovars suggest they have been exposed to different stresses including, phage, transposons and prolonged externalisation. The two serovars possess distinct complements of metabolic genes; many of which cluster into pathways for catabolism of carbon sources.