Prevalent Serovars Research Articles

Characterization and evolution of Salmonella CRISPR-Cas systems.

Prokaryotic CRISPR-Cas (clustered regularly interspaced short palindromic repeats and CRISPR-associated genes) systems provide adaptive immunity from invasive genetic elements and encompass three essential features: (i) cas genes, (ii) a CRISPR array composed of spacers and direct repeats and (iii) an AT-rich leader sequence upstream of the array. We performed in-depth sequence analysis of the CRISPR-Cas systems in >600 Salmonella, representing four clinically prevalent serovars. Each CRISPR-Cas feature is extremely conserved in the Salmonella, and the CRISPR1 locus is more highly conserved than CRISPR2. Array composition is serovar-specific, although no convincing evidence of recent spacer acquisition against exogenous nucleic acids exists. Only 12 % of spacers match phage and plasmid sequences and self-targeting spacers are associated with direct repeat variants. High nucleotide identity (>99.9 %) exists across the cas operon among isolates of a single serovar and in some cases this conservation extends across divergent serovars. These observations reflect historical CRISPR-Cas immune activity, showing that this locus has ceased undergoing adaptive events. Intriguingly, the high level of conservation across divergent serovars shows that the genetic integrity of these inactive loci is maintained over time, contrasting with the canonical view that inactive CRISPR loci degenerate over time. This thorough characterization of Salmonella CRISPR-Cas systems presents new insights into Salmonella CRISPR evolution, particularly with respect to cas gene conservation, leader sequences, organization of direct repeats and protospacer matches. Collectively, our data suggest that Salmonella CRISPR-Cas systems are no longer immunogenic; rather, their impressive conservation indicates they may have an alternative function in Salmonella.

Outbreak of leptospirosis: reproductive losses in sheep

Sheep are considered less susceptible to leptospirosis than other livestock species, and reports of reproductive problems are scarce in scientific literature. Thus, our objective was to report an epidemic outbreak of leptospirosis in a flock in southern Brazil, causing economic impact represented by several numbers of abortions and barren ewes. From a flock of 602 sheep, 79 ewes had problems during gestational period. Blood samples were collected from 25 of these 79 ewes, 10 with confirmed abortion, 10 barren, and 5 ewes that delivered normally. Serum was separated and subjected to serological evaluation. Samples were examined for Leptospira antibodies by the microscopic agglutination test (MAT) as well as subjected to a differential diagnosis for toxoplasmosis and neosporosis. From the 25 sera analyzed, 19 (76 %) were positive while 6 (24 %) were negative, with single serovar response observed in 12/19 (63.16 %) while mixed serovar positivity was observed in 7/19 (36.84 %). Regarding to serovar prevalence, Hardjo titration was observed in 15/19 (78.95 %) and Wolffi in 9/19 (47.37 %). No samples were positive for toxoplasmosis or neosporosis. Therefore, based on the serological results reached by MAT, it is possible to strongly suggest the participation of Leptospira spp., especially serovars Hardjo and Wolffi, in the reproductive flaws reported in this short communication.

Prevalence and Characterization of Salmonella Isolated from Beef in Namibia

Aim: The purpose of this research was to determine the prevalence of Salmonella in raw beef produced from selected commercial abbatoirs in Namibia. Methodology: A total of 9508 of beef samples from three different types of samples; meat cuts, carcass swabs and meat fluid were collected from the three local abattoirs over a period of two years starting from January 2008 to December 2009. Pre - enrichment for isolati on of Salmonella was done in Buffered peptone water followed by enrichment in the Rappaport - Vassiliadis and selenite cystine broth. The isolation of Salmonella was done on Xylose Lysine Desoxycholate and Brilliant Green agar followed by biochemical confirm ation and serotyping according to Kauffman White scheme. Results: The overall prevalence of Salmonella was 0.85 % for beef samples derived from meat cuts, meat fluid and carcass swabs. The prevalence of Salmonella in carcass swabs (2.67 %) was significantly different ( P = 0.0 5) from that of meat cuts (0.50 % ) and meat fluid (0.43 %). No significant difference ( P = 0.05) on the prevalence of Salmonella existed between the meat cuts and meat fluid. A total of 34 different types of Salmonella serovars were identified with S. Chester being the most frequently isolated serovars (n = 12), followed by S. Reading and S . Bredeney (n = 6) and S. Typhimurium (n = 5). Conclusions: The prevalence of Salmonella in raw beef found in this survey was lower than those observed in Sub Sahara Africa with S. Chester being the most prevalent serovar. Original Research Article

Development of a Multiplex Polymerase Chain Reaction Method for <i>cps</i> Typing of <i>Actinobacillus pleuropneumoniae </i>Serovars 1, 2, 5, 7, and 15

We developed a multiplex polymerase chain reaction (PCR) method using primers specific to the capsular polysaccharide biosynthesis genes (cps) to type Actinobacillus pleuropneumoniae serovars 1, 2, 5, 7, and 15. This multiplex PCR method may be useful for the typing of serovar 15, which is recently becoming more prevalent, as well as the most prevalent serovars 1, 2, 5, and 7 in Japan. Discipline: Animal health Additional key words: pig, pleuropneumonia, serotyping * Corresponding author: e-mail itohiroy@affrc.go.jp Received 7 October 2014; accepted 24 December 2014. Introduction Actinobacillus pleuropneumoniae is an etiologic agent of porcine pleuropneumonia that causes serious economic losses in the pig-rearing industry (Gottschalk 2012). Fifteen serovars of A. pleuropneumoniae have been identified to date, mainly based on the antigenic diversity of their capsular polysaccharides (Blackall et al. 2002, Perry et al. 1990). The prevalent local serovars vary among countries (Gottschalk 2012); in Japan, serovars 2 (59%), 1 (28%), 5 (8%), and 7 (3%) account for approximately 98% of the strains isolated from pigs (Asawa et al. 1995, Fukuyasu et al. 1991, 1996, Kume & Nakai 1988, Morioka et al. 2006, 2008, Suzuki et al. 1989, Yoshimura et al. 2002). However, the incidence of isolated cases of serovar 15, which is the most recently identified serovar (Blackall et al. 2002), has been recently increasing in Japan (Ito 2013, Morioka et al. 2008). Because the virulence of strains differs depending on their serovars and differences in serovars affect the effectiveness of vaccines (Gottschalk 2012), serotyping is widely performed in veterinary diagnostic laboratories. However, cross-reactions are often observed among different serovars, for example, among serovars 1, 9, and 11 (Gottschalk 2012), serovars 3, 6, 8, and 15 (Gottschalk 2012), serovars 4 and 7 (Gottschalk 2012), and serovars 7 and 15 (Blackall et al. 2002, Koyama et al. 2007), preventing the accurate and rapid typing of field strains. In the last decade, serovar-specific polymerase chain reaction (PCR) typing methods based on the sequence variation in genes involved in capsular polysaccharide biosynthesis (cps) have been developed for serovars 1-3, 5-8, 10, 12, and 15 (Angen et al. 2008, Bosse et al. 2014, Ito 2010, Jessing et al. 2003, Lo et al. 1998, Schuchert et al. 2004, Turni et al. 2014, Zhou et al. 2008). These PCR typing methods facilitate the reliable typing of A. pleuropneumoniae serovars without cross-reactions and mistyping. In the present study, we developed a multiplex PCR method for cps typing of A. pleuropneumoniae serovars 1, 2, 5, and 7, which are the most prevalent in Japan (Asawa et al. 1995, Fukuyasu et al. 1991, 1996, Kume & Nakai 1988, Morioka et al. 2006, 2008, Suzuki et al. 1989, Yoshimura et al. 2002), as well as serovar 15, isolated cases of which have been increasing (Ito 2013, Morioka et al. 2008). Materials and methods We used the A. pleuropneumoniae serovar reference strains serovar 1, 4074; serovar 2, S1536; serovar 3, S1421; serovar 4, M62; serovar 5a, K17; serovar 6, Femo, serovar 7, WF83, serovar 8, 405; serovar 9; CVJ13261; serovar 10, D13039; serovar 11; 56153; serovar 12, 8329; serovar 13, N273; serovar 14, 4906; and serovar 15, HS143, to determine suitable conditions for multiplex PCR. Seventy-

English

The aim of this study was to investigate the occurrence of antibodies against Leptospira spp. and risk factors related to the epidemiology of leptospirosis in dogs living in the urban area of the municipality of Uberlandia, Minas Gerais, Brazil. Blood serum samples were examined from 268 dogs from the municipality’s North, South, East, West and Central sanitary districts. The samples were collected during an animal vaccination campaign against rabies in August 2008. The occurrence of antibodies against specific leptospiral serovars was determined by the microscopic agglutination test (MAT). Multivariable logistic regression was used to evaluate the association between sex, age, previous vaccination, habitation, presence of rats, and history of human and/or animal leptospirosis on the occurrence of infection. The occurrence of canine leptospirosis was 28.36% (76/268), the most prevalent serovars were: Autumnalis (34.21%), Tarassovi (23.58%), Canicola (17.11%) and Grippotyphosa (14.47%). No risk factors were found to be statistically significant (p> 0,05 for all examined variables). The fact that close to 30% of dogs showed evidence of past infection with Leptospira points to the need for the adoption of preventive measures, as the disease may represent a public health risk.

How important are rats as vectors of leptospirosis in the Mekong Delta of Vietnam?

Leptospirosis is a zoonosis known to be endemic in the Mekong Delta of Vietnam, even though clinical reports are uncommon. We investigated leptospira infection in rats purchased in food markets during the rainy season (October) (n=150), as well as those trapped during the dry season (February–March) (n=125) in the region using RT-PCR for the lipL32 gene, confirmed by 16S rRNA, as well as by the microscopic agglutination test (MAT). Results were compared with the serovar distribution of human cases referred from Ho Chi Minh City hospitals (2004–2012) confirmed by MAT (n=45). The MAT seroprevalence among rats was 18.3%. The highest MAT seroprevalence corresponded, in decreasing order, to: Rattus norvegicus (33.0%), Bandicota indica (26.5%), Rattus tanezumi (24.6%), Rattus exulans (14.3%), and Rattus argentiventer (7.1%). The most prevalent serovars were, in descending order: Javanica (4.6% rats), Lousiana (4.2%), Copenageni (4.2%), Cynopterie (3.7%), Pomona (2.9%), and Icterohaemorrhagiae (2.5%). A total of 16 rats (5.8%) tested positive by RT-PCR. Overall, larger rats tended to have a higher prevalence of detection. There was considerable agreement between MAT and PCR (kappa=0.28 [0.07–0.49]), although significantly more rats were positive by MAT (McNemar 29.9 (p<0.001). MAT prevalence was higher among rats during the rainy season compared with rats in the dry season. There are no current available data on leptospira serovars in humans in the Mekong Delta, although existing studies suggest limited overlapping between human and rat serovars. Further studies should take into account a wider range of potential reservoirs (i.e., dogs, pigs) as well as perform geographically linked co-sampling of humans and animals to establish the main sources of leptospirosis in the region.

Evaluación serológica a Leptospira spp. en equinos aparentemente sanos en municipios del Meta y Guaviare, Colombia

Introduction. Leptospirosis is the most disseminated zoonotic disease worldwide, and it causes serious economic loses in several animal species. There are few serological studies in Colombia applied to horses, so the reactivity of the main serovars is unknown. Objective. Determine the sanitary status of leptospira spp in apparently healthy horses and identify the main serovars. At the same time, we intend to relate seropositivity with the age, the age group and the sex of the animals. Materials and methods. A transversal study was performed in (n=94) horses from four towns located in the Guaviare and Meta provinces. As a diagnostic test, the microscopic agglutination (MAT) test was used before 10 serovars. Results. The seroprevalence in the subpopulations were L. Pomona, 41.5 %; L icterohaemorragiae, 40.4 %; L. grippothyposa, 24.5 %; L. javanica 23.4 %; L. canicola, 16 %; L. hardjoprajitno 10.6 %; L tarassovi, 7,4 %, L. hebdomadis, 7,4 %; L. wolffi, 2,1 % and L. Bratislava, 1,1 %. 23.4 % of the animals had no serological reactivity, and the response to one or more serovars was 76.6 %. Conclusion. The most prevalent serovars were Pomona and cterohaemorragaiae, and this can be a reflex of the specific epidemiological conditions of the towns the animals come from.

Seroepidemiological survey of leptospiral infection in stray dogs in Serbia

Leptospirosis is a bacterial zoonosis with worldwide distribution. This disease is facilitated among stray dogs due to their lifestyle and the absence of immunoprophylaxis. The aim of the present study was to provide serological data on the presence of certain serovars of Leptospira spp., which are assumed to circulate in the population of stray dogs in Serbia. During a period of 3 years (from April 2010 to June 2013), 1045 canine sera originating from 11 shelters were submitted to the laboratory of the Department of Infectious Animal Diseases and Diseases of Bees, Faculty of Veterinary Medicine, Belgrade. A microscopic agglutination test (MAT) was performed to detect antibodies to Leptospira (cutoff, 1:100). The overall seroprevalence was 5.45% (57/1045) and the most prevalent Leptospira serovars were Icterohaemorrhagiae 33.3% (19/57), Pomona 29.8% (17/57), Canicola 14.0% (8/57), Grippotyphosa 3.5% (2/57), Bataviae 1.7 % (1/57), and Sejroe 1.7% (1/57). All dogs were seronegative for antibodies against serovars Australis and Bratislava. The results showed that stray dogs contribute to the spread and maintenance of Leptospira spp. İn Serbia. Due to close contact with humans it is very important to improve the prevention of leptospirosis in dogs and support a One Health approach.

In silico scrutiny of genes revealing phylogenetic congruence with clinical prevalence or tropism properties of Chlamydia trachomatis strains.

Microbes possess a multiplicity of virulence factors that confer them the ability to specifically infect distinct biological niches. Contrary to what is known for other bacteria, for the obligate intracellular human pathogen Chlamydia trachomatis, the knowledge of the molecular basis underlying serovars’ tissue specificity is scarce. We examined all ~900 genes to evaluate the association between individual phylogenies and cell-appetence or ecological success of C. trachomatis strains. Only ~1% of the genes presented a tree topology showing the segregation of all three disease groups (ocular, urogenital, and lymphatic) into three well-supported clades. Approximately 28% of the genes, which include the majority of the genes encoding putative type III secretion system effectors and Inc proteins, present a phylogenetic tree where only lymphogranuloma venereum strains form a clade. Similarly, an exclusive phylogenetic segregation of the most prevalent genital serovars was observed for 61 proteins. Curiously, these serovars are phylogenetically cosegregated with the lymphogranuloma venereum serovars for ~20% of the genes. Some clade-specific pseudogenes were identified (novel findings include the conserved hypothetical protein CT037 and the predicted α-hemolysin CT473), suggesting their putative expendability for the infection of particular niches. Approximately 3.5% of the genes revealed a significant overrepresentation of nonsynonymous mutations, and the majority encode proteins that directly interact with the host. Overall, this in silico scrutiny of genes whose phylogeny is congruent with clinical prevalence or tissue specificity of C. trachomatis strains may constitute an important database of putative targets for future functional studies to evaluate their biological role in chlamydial infections.

Seroprevalence of Leptospirosis in Clinically Ailing Bovine

The purpose of this study was to carried out seroepidemiological study of leptospirosis in clinically ailing cattle and buffaloes of South Gujarat where cases of leptospirosis in human is increase every monsoon since last decade. To determine clinical pattern of bovine Leptospirosis in this area a total of 130 serum samples of cattle and buffaloes were collected randomly from different age groups of cattle and buffaloes of either sex reared in this area and tested by microscopic agglutination test (MAT) using different serovars of Leptospira spp. The prevalence of leptospiral antibodies was detected in 15.84 and 17.24% in clinically ailing cattle and buffaloes, respectively. In clinically ailing seropositive cattle history of mastitis/agalactia/oligolactia was recorded in maximum number of cases (24.00%) followed by abortion (20.00%), fever (14.81%), repeat breeding (11.76%) and anorexia (5.88%) in different combinations. In seropositive clinically ailing buffaloes the clinical signs included mastitis (30.00%), fever (16.66%) and abortion (14.28%). In clinically ailing cattle highest prevalence was noted in animals above 4 years of age (20.00%) followed by 1–4 years of age (4.76%) whereas in clinically ailing buffalo seropositivity was recorded only in above 4 years of age (20.00%). The most prevalent serovar pomona has been reported from different clinical conditions in both cattle and buffaloes. Based on present and few past investigation reports the sero-epidemiological condition of bovine leptospirosis that need due attention as South Gujarat region is endemic zone for leptospirosis.

Prevalence of Serum Antibodies against Six Leptospira Serovars in Buffaloes in Tabriz, Northwestern Iran

Leptospirosis is an important zoonotic infectious and its prevalence is unknown in buffalo in Iran particularly in Tabriz, northwest of the country. To survey the prevalence of Leptospira infection in buffaloes in Tabriz, blood samples were collected from 85 female buffaloes slaughtered in Tabriz industrial slaughterhouse from December 2008 to November 2009. Sera were stored at -20°C until they were examined. Sera were initially screened at serum dilution of 1:100 against six live antigens of Leptospira interrogans, Pomona, Canicola, Hardjo, Ballum, Icterohaemorrhagiae and Grippotyphosa by using the microscopic agglutination test (MAT).The samples were considered positive if 50% or more of agglutination of leptospire in a dilution tests serum of l:100 were observed. 30 serums (35.29%) at dilution 1:100 were positive against 1 or 2 of serovars. the highest prevalent serovar in buffalo was Grippotyphosa (51.3%), and fallowed whit Pomona (29.7%), canicola (10.8%) and Icterohaemorrhagiae (8.1%). All of the samples were seronegative for serovar Ballum and Hardjo. Statistical analysis of the results showed that the rates of the infection in the autumn-winter and spring–summer didn’t have significant difference (p &gt; 0/05). The rate of the infection has been statistically increased with the aging (p&lt;0/05) and the animals with 3 and 4 pair’s permanent teeth had the highest infection rates. The serological infection rate in buffaloes in Tabriz is relatively high and it appears that it is because of living type of buffaloes in water and swamp, thus consequently the preventive methods must be applied to control of the disease.

Pathogenicity and phenotypic analysis of sopB, sopD and pipD virulence factors in Salmonella enterica serovar typhimurium and Salmonella enterica serovar Agona.

Salmonella is an important food-borne pathogen causing disease in humans and animals worldwide. Salmonellosis may be caused by any one of over 2,500 serovars of Salmonella. Nonetheless, Salmonella enterica serovar Typhimurium and Salmonella enterica serovar Agona are the second most prevalent serovars isolated from humans and livestock products respectively. Limited knowledge is available about the virulence mechanisms responsible for diarrheal disease caused by them. To investigate the contribution of sopB, sopD and pipD as virulence factors in intracellular infections and the uniqueness of these bacteria becoming far more prevalent than other serovars, the infection model of Caenorhabditis elegans and phenotypic microarray were used to characterize their mutants. The strains containing the mutation in sopB, sopD and pipD genes were constructed by using latest site-specific group II intron mutagenesis approach to reveal the pathogenicity of the virulence factors. Overall, we observed that the mutations in sopB, sopD and pipD genes of both serovars did not exhibit significant decrease in virulence towards the nematode. This may indicate that these virulence effectors may not be universal virulence factors involved in conserved innate immunity. There are significant phenotypic differences amongst strains carrying sopB, sopD and pipD gene mutations via the analysis of biochemical profiles of the bacteria. Interestingly, mutant strains displayed different susceptibility to chemical stressors from several distinct pharmacological and structural classes when compared to its isogenic parental strains. These metabolic and chemosensitivity assays also revealed multiple roles of Salmonella virulence factors in nutrient metabolism and antibiotic resistance.

Avaliação do controle de leptospirose por vacinação em bovinos de propriedade leiteira no estado do Piauí

Neste estudo foram colhidos soros de 255 vacas e 2 touros no período de 2004 a 2009, em intervalos de seis meses, em uma fazenda de gado leiteiro no município de Buriti dos Lopes, Piauí. Pela técnica de soroaglutinação microscópica (SAM), os sorovares de leptospiras encontrados foram Hardjobovis, Hardjoprajitno (Norma), Hardjoprajitno (OMS). Para o controle da leptospirose, foi testada uma vacina contendo os mesmos sorovares encontrados infectando o rebanho. Os resultados mostraram que em bovinos leiteiros na bacia de Parnaíba, no Piauí, ocorre leptospirose, com predominância do sorovar Hardjobovis. A utilização de uma vacina contendo as sorovariedades mais prevalentes no rebanho, aplicada semestralmente ao longo de cinco anos, foi importante para a redução dos títulos de anticorpos, além de reduzir os problemas reprodutivos no rebanho.

Multi-laboratory evaluation of the rapid genoserotyping array (SGSA) for the identification of Salmonella serovars

Salmonella serotyping is an essential first step for identification of isolates associated with disease outbreaks. The Salmonella genoserotyping array (SGSA) is a microarray-based alternative to standard serotyping designed to rapidly identify 57 of the most commonly reported serovars through detection of the genes encoding surface O and H antigens and reporting the corresponding serovar in accordance with the existing White–Kaufmann–Le Minor serotyping scheme. In this study, we evaluated the SGSA at 4 laboratories in 3 countries by testing 1874 isolates from human and non-human sources. The SGSA correctly identified 96.7% of isolates from the target 57 serovars. For the prevalent and clinically important Salmonella serovars Enteritidis and Typhimurium, test specificity and sensitivity were greater than 98% and 99%, respectively. Due to its high-throughput nature, the SGSA is a rapid and cost-effective alternative to standard serotyping for identifying the most prevalent serovars of Salmonella.

Prevalence, characterization and antibiotic resistance of Salmonella isolates in large corvid species of europe and north America between 2010 and 2013.

It is well understood that Salmonella is carried by animals and in majority of cases as asymptomatic hosts. Surveillance efforts have focused on the role of agriculture and contamination points along the food chain as the main source of human infection; however, very little attention has been paid to the contribution of wildlife in the dissemination of Salmonella and what effect anthropogenic sources have on the circulation of antibiotic resistant Salmonella serovars in wildlife species. A purposive survey was taken of large corvids roosting yearly between November and March in Europe and North America. Two thousand and seven hundred and seventy-eight corvid faecal specimens from 11 countries were submitted for Salmonella spp. culture testing. Presumptive positive isolates were further serotyped, susceptibility tested and analysed for antibiotic resistance genes. Overall, 1.40% (39/2778) (CI = 1.01, 1.90) of samples were positive for Salmonella spp. Salmonella Enteritidis was the most prevalent serovar followed by S. Infantis, S. Montevideo and S. Typhimurium. No significant difference (P > 0.05) was found in the proportion of Salmonella recovered in Europe versus North America. The most variability of serovars within a site was in Kansas, USA with five different serovars recovered. European sites were significantly more likely to yield Salmonella resistant to more than one antibiotic (OR 71.5, P < 0.001, CI = 3.77, 1358) than North American sites, where no resistance was found. Resistance to nalidixic acid, a quinolone, was recovered in nine isolates from four serovars in four different sites across Europe. Large corvids contribute to the transmission and dissemination of Salmonella and resistance genes between human and animal populations and across great distances. This information adds to the knowledge base of zoonotic pathogen prevalence and antibiotic resistance ecology in wild birds.

Preliminary Investigations on the Distribution of Leptospira Serovars in Domestic Animals in North-west Morocco.

Leptospirosis is a neglected zoonosis of global importance with a complex epidemiology that affects humans, domestic and wild mammals. However, due to the diversity of clinical signs and difficulties of establishing a confirmatory laboratory diagnosis, the disease remains poorly investigated, particularly in the developing world. In Morocco, a descriptive study of the seroprevalence of Leptospira infection in animals has never been undertaken. To fill this gap, the current study was conducted on a subset of animals in north-west Morocco as a preliminary step towards understanding the epidemiological patterns of animal leptospirosis in the country. The study was conducted on 289 serum samples collected between January and April 2012 from dogs, cattle, sheep, goats and donkeys in the areas of Rabat-Temara, Sidi Kacem and Oulmes. All serum samples were tested by the MAT with 14 reference strains of the most prevalent pathogenic serovars of Leptospira and two serovars of non-pathogenic Leptospira. The overall seroprevalence of Leptospira in cattle, sheep, goats, dogs and donkeys was 15%, 18%, 20%, 21% and 20%, respectively. The most prevalent serogroups found in each species were Ballum, Sejroe, and Australis in cattle, Ballum, Australis and Sejroe in sheep, Australis and Ballum in goats, Javanica and Australis in donkey and Australis, Ballum and Canicola in dogs. Of all the serogroups tested in this study, Icterohaemorrhagiae, the only serogroup which has been previously reported in humans in Morocco, was rarely reactive. The majority of reactive sera were collected from low land areas. A large number of sera samples classified as seronegative when tested against pathogenic leptospires were positive when tested against non-pathogenic leptospires; this is suggestive of possible novel, as yet unclassified, Leptospira serovars in Morocco. Eleven of thirteen sheep urine samples were positive by real-time PCR confirming their role as Leptospira carriers in Morocco.

Prevalence of leptospirosis and toxoplasmosis: a study of rodents and shrews in cultivated and fallow land, Morogoro rural district, Tanzania.

Leptospirosis and toxoplasmosis are among understudied zoonotic diseases that are also not diagnosed routinely in Tanzania. Humans get leptospirosis and toxoplasmosis through contact with an environment contaminated with Leptospira bacteria and Toxoplasma protozoa from reservoir hosts, which are rodents and cats, respectively. The objective of this study was to determine the prevalence of Leptospira and Toxoplasma infections in rodents and shrews in Mikese area of Morogoro Rural District in eastern Tanzania. A total of 89 rodents and one shrew from cultivated and fallow land were tested for leptospirosis using six Leptospira serovars: Sokoine, Kenya, Canicola, Lora, Hebdomadis and Pomona. Toxoplasmosis was determined in 46 rodents brain smears. The prevalence of leptospirosis was 25.8%, and Leptospira serovar Sokoine was the most prevalent serovar (16.9%). Toxoplasma was detected in one rodent (2.17%) individual while three rodent individuals had Toxoplasma-like parasites hence were considered suspect positive. Findings suggest potential existence of human leptospirosis which needs to be further investigated. Public awareness of leptospirosis and toxoplasmosis should be promoted and their diagnosis considered in patients in health care facilities.

Genome comparison of three serovar 5 pathogenic strains of Haemophilus parasuis: insights into an evolving swine pathogen.

Haemophilus parasuis is the causative agent of Glässer's disease, a systemic disorder characterized by polyarthritis, polyserositis and meningitis in pigs. Although it is well known that H. parasuis serovar 5 is the most prevalent serovar associated with the disease, the genetic differences among strains are only now being discovered. Genomes from two serovar 5 strains, SH0165 and 29755, are already available. Here, we present the draft genome of a third H. parasuis serovar 5 strain, the formal serovar 5 reference strain Nagasaki. An in silico genome subtractive analysis with full-length predicted genes of the three H. parasuis serovar 5 strains detected 95, 127 and 95 strain-specific genes (SSGs) for Nagasaki, SH0165 and 29755, respectively. We found that the genomic diversity within these three strains was high, in part because of a high number of mobile elements. Furthermore, a detailed analysis of large sequence polymorphisms (LSPs), encompassing regions ranging from 2 to 16 kb, revealed LSPs in virulence-related elements, such as a Toll-IL receptor, the AcrA multidrug efflux protein, an ATP-binding cassette (ABC) transporter, lipopolysaccharide-synthetizing enzymes and a tripartite ATP-independent periplasmic (TRAP) transporter. The whole-genome codon adaptation index (CAI) was also calculated and revealed values similar to other well-known bacterial pathogens. In addition, whole-genome SNP analysis indicated that nucleotide changes tended to be increased in membrane-related genes. This analysis provides further evidence that the genome of H. parasuis has been subjected to multiple lateral gene transfers (LGTs) and to fine-tuning of virulence factors, and has the potential for accelerated genome evolution.

Identification and characterization of Salmonella enterica subsp. enterica serovar Derby isolates carrying a new aadA26 gene cassette in a class 1 integron obtained at pig slaughterhouses.

Salmonella enterica subsp. enterica (S.) serovar Derby is one of the most prevalent serovars in pigs. Twenty-seven multiresistant S. Derby isolates, obtained at two pig slaughterhouses in Southern Brazil, were investigated for their molecular relationships, genotypic resistance and presence of class 1 and 2 integrons. All isolates shared the same XbaI-macrorestriction pattern and showed a common resistance genotype with resistance to streptomycin/spectinomycin (aadA variant), sulphonamides (sul1) and tetracycline [tet(A)]. They carried chromosome-located class 1 integrons with a new aadA gene variant, designated aadA26, as part of a gene cassette. The sequence of the flanking regions of this integron and the amplification of the merA gene may indicate the location of the class 1 integron into a Tn21-related transposon. The close relationships among these isolates and isolates from an earlier study suggest the persistence of a resistant clone of S. Derby in the pig production chain in Southern Brazil.

Prevalence and spatial analysis of antileptospiral agglutinins in dairy cattle - Microregion of Sete Lagoas, Minas Gerais, 2009/2010

The aim of this study was to evaluate the seroprevalence of leptospirosis in the dairy herds from Minas Gerais, Brazil, during the years 2009 and 2010. A total of 2,915 serum samples were collected from the lactating cows of 151 properties in eleven municipalities located in the Sete Lagoas region. The Microscopic Agglutination Test was used to detect antileptospiral agglutinins. An individual animal prevalence of 20.7% (95% CI = 17.1% - 24.3%) and a herd prevalence of 80.8% (95% CI = 73.8% = 87.7%) were determined. The most prevalent serovars were hardjoprajitno at 19.4%; hardjoprajitnostrain Norma at 17.4%; and hardjo-bovis at 17.4%. These results show the significance of the hardjo serovar in bovine leptospirosis cases in Minas Gerais.