No abstract

The aim of the present study was to determine the prevalence of Coxiella burnetii antibodies in small ruminants in Southeast Iran. A total of 368 small ruminant blood samples (241 caprine blood samples and 127 ovine blood samples) were collected from January to May of 2011 in Southeast Iran. A commercial ELISA test kit was employed to identify specific antibodies against C. burnetii in the sheep and goats. Seropositivity in the examined counties ranged from 17.1% to 39.2%. Of the animals tested, 97 animals (26.4%), including 43 sheep (33.9%) and 54 goats (22.4%), had antibodies to C. burnetii. The results of the current study reveal the high prevalence of antibody positivity in small ruminants in Southeast Iran. Thus, sheep and goats are important reservoirs in this area. Additionally, we performed a logistic regression to the identify risk factors for positivity and concluded that age was an important risk factor (P<0.001).

No abstract

Background Clostridium perfringens (C. perfringens), a major enteric pathogen, can lead to both clinical and subclinical disease in broiler chickens. 1 This bacterium was divided to five types (A, B, C, D and E) based on the presence of major toxins (α, β, ε and ι). It produced some important minor toxins such as enterotoxin, beta 2 , necrotic enteritis toxin B (NetB), TpeL and perfringolysin O (PFO). 2 C. perfringens is responsible for causing necrotic enteritis (NE) of poultry, especially by type A and rarely type C. 3 C. perfringens type A is the most frequently isolated clostridial type from NE cases. 4,5 NE is an economically important disease with severe gastro-intestinal signs in commercial broiler farms and was reported for the first time by Parish. 6 Two forms of NE were described: clinical and subclinical. 7 Clinical NE, primarily in young chickens (between two to six weeks), is characterized by severe necrosis in the mucosa of proximal jejunum and associated with high mortality rates. 8 Subclinical NE is led to a decreased performance (reduced growth, reduced feed efficiency) without mortality, due to the extensive mucosal damage. 9 Keyburn et al discovered a pore forming toxin of C. per-fringens which they named NetB and the encoding gene, netB and recognized this gene in C. perfringens isolates recovered from chickens. They showed the relationship between presence of netB gene and NE outbreaks and reported that NetB is critical to the development of NE, in chickens. 10 To our knowledge, there were not published data about NE outbreaks and responsible toxins for causing this disease in organic broiler farms. Objectives This study was firstly aimed to genotype the pathogenic C. perfringens isolates in organic broiler farms and secondly to assess the presence of netB gene among them and its occurrence with respect to the disease NE. Materials and Methods Sampling A total of 103 intestinal samples of broiler chickens, clinically suspected to NE, were obtained from eight organic farms. Samples were collected aseptically in plastic bags in the post-mortem examination of chickens and quickly transported to the laboratory in ice-cooled containers.

Background Clostridium perfringens (C. perfringens) is a gram positive, sporulating bacterium that is extremely pathogenic and responsible for a wide spectrum of anaerobic diseases in animals and humans. This bacterium is widely spread in the soil and the gastrointestinal tract of animals and is classified into five toxinotypes (A, B, C, D, and E) based on the production of one or more of the four main toxins (α, β, ε, and ι) 1 which are responsible for specific enterotoxemia in animals. 2 Enterotoxaemia is one of the most widespread lethal diseases in ruminants. This disease is indicated when a high level of toxins produced in the gut contents may be absorbed into the general circulation. 3,4 Typing C. perfringens strains is important, because different types of bacteria are associated with specific enteric diseases in animals. 5 Traditional methods have some limitations for bacterium typing. Serum neutralization test, enzyme-linked immunosorbent assay (ELISA), and polymerase chain reaction (PCR) have been previously used for the classification of C. perfringens, 5 among which PCR is the best choice for typing and sub-typing. Various PCR protocols have been established for the typing of C. perfringens isolates. 6 PCR has been applied in several studies and highlighted as a rapid and accurate method for the detection of low copy numbers of genes. This method is more accurate and faster than conventional methods. 7 Objectives To the best of our knowledge, there is a lack of data on the prevalence and typing of C. perfringens strains in Yazd ruminant farms. Therefore, we used PCR for typing toxigenic C. perfringens strains in this field. Materials and Methods Samples In total, 485 fecal and intestinal samples were investigated from the following species: domestic sheep (n = 206), goat (n = 129), and cow (n = 150). Collection and preparation of the samples was performed as previously described by Alimolaei, et al. 8 Bacterial strains were isolated from the samples and the isolated colonies were analyzed according to the shape, color, type of hemolysis, and gram staining smears as described by MacFaddin. 9 Biochemical identification of the catalase negative colonies presenting C. perfringens characteristics was performed as described

The alpha-toxin is one of the virulence factors of Clostridium perfringens for gas gangrene in humans and animals or necrotic enteritis in poultry. The C-terminal domain of this toxin ( cpa ) was synthesized and cloned into pT1NX vector to construct the pT1NX-alpha plasmid. This surface-expressing plasmid was electroporated into Lactobacillus casei ATCC 393, generating the recombinant L. casei strain expressing alpha-toxoid (LC-α strain). Expression of this modified alpha-toxoid was confirmed by SDS-PAGE, immunoblotting, and direct immunofluorescence microscopy. BALB/c mice, immunized orally by the recombinant LC-α strain, elicited mucosal and significantly humoral immune responses (p< 0.05) and developed a protection against 900 MLD/mL of the standard alpha-toxin. This study showed that this recombinant LC-α strain could be a promising vaccine candidate against gas gangrene and necrotic enteritis.

No abstract

No abstract