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A satisfactory investigation of buffaloes hemorrhagic septicemia was obtained in the marshes of Dhi Qar governorate in southern Iraq. Has described the clinical and pathological symptoms and exterior morphology of bacterial colonies and biochemical behavior of Pasterulla multocida. Gross and histopathological changes were recorded also in 13 samples collected from infected and dead animals.

Hemorrhagic septicemia (HS) caused by Pasteurella multocida B:2 and E:2 is among the fatal bacterial diseases in cattle and buffaloes that are economically valuable in Asian and African countries. The current work aims to study the prevalence of HS among buffaloes, cattle, sheep, and goats in 41 countries in 2005–2019. The data analysis revealed that 74.4% of the total infection rate in the world was distributed among cattle, followed by buffaloes (13.1%). The mortality of HS among cattle and buffaloes increased in 2017–2019 compared to the period between 2014 and 2016. The best measure to control the disease is through vaccination programs. Current commercial vaccines, including live-attenuated vaccines and inactivated vaccines, have some shortcomings and undesirable effects. Virus-like particles (VLPs) have more potential as a vaccine platform due to their unique properties to enhance immune response and the ability to use them as a platform for foreign antigens against infectious diseases. VLPs-based vaccines are among the new-generation subunit vaccine approaches that have been licensed for the human and veterinary fields. However, most studies are still in the late stages of vaccine evaluation. [ABSTRACT FROM AUTHOR]

Epizootic hemorrhagic disease virus (EHDV), an arthropod-borne orbivirus (family Reoviridae), is an emerging pathogen of wild and domestic ruminants closely related to bluetongue virus (BTV). EHDV serotype 6 (EHDV6) has recently caused outbreaks close to Europe in Turkey and Morocco and a recent experimental study performed on calves inoculated with these two EHDV6 strains showed that the young animals have remained clinically unaffected. The aim of this study was to investigate the pathogenicity of an EHDV6 strain from La Reunion Island in adult Holstein (18-month-old heifers). This EHDV6 strain has induced clinical signs in cattle in the field. Samples taken throughout the study were tested with commercially available ELISA and real-time RTPCR kits. Very mild clinical manifestations were observed in cattle during the experiment although high levels of viral RNA and virus were found in their blood. EHDV was isolated from the blood of infected animals at 8 dpi. Antibodies against EHDV were first detected by 7 dpi and persisted up to the end of the study. Virus was detected in various tissue samples until 35 dpi, but was not infectious. In view of the recent circulation of different arboviruses in Europe, this study demonstrates what the EHD induces a strong viraemia in adult Holstein cattle and shows that a spread of EHD on European livestock cattle is possible. [ABSTRACT FROM AUTHOR]

Viral Hemorrhagic Septicemia virus (VHSv) is one of the world's most serious fish pathogens, infecting >80 marine, freshwater, and estuarine fish species from Eurasia and North America. A novel and especially virulent strain – IVb – appeared in the Great Lakes in 2003, has killed many game fish species in a series of outbreaks in subsequent years, and shut down interstate transport of baitfish. Cell culture is the diagnostic method approved by the USDA-APHIS, which takes a month or longer, lacks sensitivity, and does not quantify the amount of virus. We thus present a novel, easy, rapid, and highly sensitive real-time quantitative reverse transcription PCR (qRT-PCR) assay that incorporates synthetic competitive template internal standards for quality control to circumvent false negative results. Results demonstrate high signal-to-analyte response (slope = 1.00±0.02) and a linear dynamic range that spans seven orders of magnitude (R2 = 0.99), ranging from 6 to 6,000,000 molecules. Infected fishes are found to harbor levels of virus that range to 1,200,000 VHSv molecules/106actb1 molecules with 1,000 being a rough cut-off for clinical signs of disease. This new assay is rapid, inexpensive, and has significantly greater accuracy than other published qRT-PCR tests and traditional cell culture diagnostics. [ABSTRACT FROM AUTHOR]

Vibrio anguillarum expresses several virulence factors and causes hemorrhagic septicemia accompanied by serious losses in marine fish. Transferrin is a glycoprotein, also known as a multitasking protein, which is mainly synthesized by the liver. It has a fundamental role in the immune system. In the present study, the transferrin gene expression of sea bass (Dicentrarchus labrax) was investigated during an experimental infection with V. anguillarum. Fish samples were examined by hematological and serological methods as well as real-time polymerase chain reaction. The infection was performed via water. The sampled fish displayed vibriosis infection symptoms, both internally and externally. The transferrin saturation in the diseased fish serum decreased dramatically and the transferrin gene expression increased during the first 2 days; however, it decreased in the subsequent days. [ABSTRACT FROM AUTHOR]

Viral haemorrhagic septicaemia ( VHS), caused by the novirhabdovirus viral haemorrhagic septicaemia virus ( VHSV), causes significant economic problems to European rainbow trout, Oncorhynchus mykiss ( Walbaum), production. The virus isolates can be divided into four distinct genotypes with additional subgroups. The main source of outbreaks in European rainbow trout farming is sublineage Ia isolates. Recently, this group of isolates has been further subdivided in to two subclades of which the Ia-2 consists of isolates occurring mainly in Continental Europe outside of Denmark. In this study, we sequenced the full-length G-gene sequences of 24 VHSV isolates that caused VHS outbreaks in Polish trout farms between 2005 and 2009. All these isolates were identified as genotype Ia-2; they divided however into two genetically distinct subgroups, that we name Pol I and Pol II. The Pol I isolates mainly caused outbreaks in the southern part of Poland, while Pol II isolates predominantly were sampled in the north of Poland, although it seems that they have been transmitted to other parts of the country. Molecular epidemiology was used for characterization of transmission pathways. This study shows that a main cause of virus transmission appears to be movement of fish. At least in Polish circumstances trading practices appear to have significant impact on spreading of VHSV infection. [ABSTRACT FROM AUTHOR]

This study describes the ultrastructural changes and distribution of P. multocida B:2 in the respiratory and gastrointestinal tracts of buffalo calves following oral exposure and compared with intratracheal exposure. Nine 8-month old buffalo calves were divided into 3 groups. At the start of the experiment, dexamethasone (1mg/kg) was injected intramuscularly into buffaloes of all groups for three consecutive days. Then, calves of Group 1 were exposed orally to 50ml of the inoculum containing 109 colony-forming unit (CFU)/mL of live P. multocida B:2. Calves of Group 2 were exposed intra-tracheal to the same inoculum while calves of Group 3 were exposed orally to PBS. Transient and mild clinical signs were observed in calves of Groups 1 and 2. Pasteurella multocida B:2 was isolated from the nasal mucosa for up to 5 days post-infection. Only calf that was killed at 48 h post-infection had P. multocida B:2 in both respiratory and gastro-intestinal tracts showing ultrastructural changes typical of acute cellular injury, with degeneration of endothelium and vascular walls. There were deciliation in the respiratory and microvilli degeneration in the gastrointestinal tracts. The study concludes that oral exposure may not play major role in the development of hemorrhagic septicemia. Nevertheless, the buffalo calf that succumbed to hemorrhagic septicemia carried P. multocida B:2 in the gastro-intestinal organs. [ABSTRACT FROM AUTHOR]

Two experiments were performed to determine the persistence of viral hemorrhagic septicemia virus (VHSV) genotype IVb on WalleyeSander vitreuseggs. Fertilized Walleye eggs were exposed for 30 min to 105plaque-forming units/mL VHSV genotype IVb, and control eggs were exposed to phosphate-buffered saline. In the first experiment, the eggs were treated with 0 and 50 mg/L iodophor and incubated at 12±1°C until the first fry emerged. In the second experiment, a treatment of 100 mg/L iodophor was also tested. Periodic samples were taken during embryo development and tested for VHSV by viral isolation and quantitative reverse-transcription polymerase chain reaction (qRT-PCR). The effect of tannic acid, an inhibitor of qRT-PCR testing, was evaluated in the second experiment. In both experiments no virus was detected in any control eggs by either test. In the first experiment, virus was isolated in 0-mg/L iodophor-treated eggs up to 3 d postinfection (DPI). Virus was also isolated in the 50-mg/L iodophor-treated group at 1 DPI. Testing by qRT-PCR detected viral RNA at all time points throughout the first experiment. In the second experiment, no VHSV was isolated after the initial 0-DPI sample. Viral RNA was again detected at all time points, including samples collected at the end of the experiment. Inhibition was found in 34 of 36 samples at 0 DPI and 21 of 36 samples at 1 DPI. The number of inhibited samples decreased over time, but virus was still detected in three samples at 24 DPI. These experiments show that VHSV persists on Walleye eggs for longer than was previously known. At early time points VHSV was still detected despite disinfection, and viral RNA was detected at all time points; however, it is unknown whether the virus detected by this qRT-PCR is viable. These experiments reinforce the need for careful disinfection of eggs. Received November 28, 2011; accepted February 26, 2012 [ABSTRACT FROM PUBLISHER]

Abstract: Pasteurella multocida serogroup B:2, a causative agent of haemorrhagic secpticaemia (HS) in cattle and buffalo especially in tropical regions of Asia and African countries, is known to possess a type IV fimbriae (pili) as one of the virulent factors. In the present study, ptfA gene encoding for type IV fimbrial subunit of P. multocida serogroup B:2 (strain p52), an Indian HS vaccine strain, has been cloned and over-expressed in recombinant Escherichia coli. The recombinant type IV fimbrial subunit protein (∼31kDa) including N-terminus histidine tag was purified under denaturing condition and confirmed by western blotting. A homology model of HS causing P. multocida serogroup B:2 fimbrial subunit has also been discussed. The study indicated the potential possibilities to use the recombinant fimbrial protein in developing HS subunit vaccine along with suitable adjuvant. [Copyright &y& Elsevier]

The article discusses the development of DNA vaccine for the treatment of viral haemorrhagic septicaemia virus (VHSV) and infectious haematopoietic necrosis virus (IHNV). It says that Oncorhynchus mykiss was vaccinated with one μg of either viral haemorrhagic septicaemia (VHS) or IHN vaccine. It mentions that subsamples of fish were removed from each holding tank to determine the relative protection of the treatments against VHS.

The efficacy of an intranasal haemorrhagic septicaemia vaccine containing live gdhA derivative Pasteurella multocida B:2 was tested in buffaloes in Sabah. Sixty buffaloes, kept grazing in the field with minimal human intervention were devided into three groups of buffaloes per group. Buffaloes of group 1 were exposed intranasal to 5 ml vaccine containing 106 CFU/ml of live gdhA derivative P multocida B:2. Buffaloes of group 2 were not exposed to the vaccine but exposed to PBS and were allowed to commingle and graze in the same field as the buffaloes of group 1 while buffaloes of group 3 were similarly exposed to PBS and were grazing separately. Booster was on group 1, two weeks later. Twelve months after the first vaccination, three buffaloes from each group were brought into the experimental house and challenged subcutaneously with 109 CFU/ml of live wild-type P multocida B:2. All challenged buffaloes of groups 1 and 2 survived with only mild, transient signs while all control unvaccinated buffaloes developed severe signs of haemorrhagic septicaemia and were euthanased between 28 hours and 38 hours postchallenge with signs and lesions typical of haemorrhagic septicaemia. These data showed that the gdhA mutant strain, given intranasally as two doses two weeks apart, successfully induced systemic immunity in exposed buffaloes and also led to spread of vaccine strain to the in-contact animals, where it acted as an effective live vaccine to protect both exposed buffaloes and in-contact buffaloes against challenge with the virulent parent strain. [ABSTRACT FROM AUTHOR]

Abstract: The olive flounder (Paralichthys olivaceus) shows a high rate of mortality to viral haemorrhagic septicaemia virus (VHSV) in the winter and spring but has zero mortality over 20 °C. In this experiment, we studied the effect of rearing temperature on viral replication, viral transcription and antiviral apoptotic immune response in VHSV-infected olive flounder by real-time polymerase chain reaction. Olive flounder were given intra-peritoneal injections of VHSV (107.8 TCID50/ml) and were reared at 15 °C or 20 °C. Five fish were randomly sampled for head kidney at 3, 6 and 12 h post-infection (hpi) and 1, 2, 4 and 7 days post-infection (dpi). Total RNA extracted from the tissue was reverse transcribed and used as template for real-time PCR. In the 15 °C group, the number of viral gRNA copies peaked after 2 dpi and remained high through 7 dpi, while in the 20 °C group, the copy number was at the highest at 1 dpi but drastically declined at later stages. Viral mRNA levels in the 15 °C group gradually increased starting at 3 hpi to reach their maximum value at 12 hpi and remained high until 2 dpi, whereas the other group showed much lower copy numbers that were undetectably low at 4 and 7 dpi. Type II IFN expression increased as the viral copies increased and the 20 °C group showed quicker and stronger expression than the 15 °C group. The MHC class I and CD8 expression was high in both the groups at early stage of infection (3–6 hpi) but at later stages (2–7 dpi) in 15 °C group expression reduced below control levels, while they expressed higher to control in 20 °C group. The expression of granzyme in 15 °C fish showed a single peak at 2 dpi, but was consistently expressing in 20 °C fish. Individuals expressed very high levels of perforin expressed very high levels of caspase 3. In 15 °C fish, TNFα, FasL and p53 expressed significantly higher than 20 °C only at initial stages of infection (3–6 hpi). Caspase 3 expression found to be low in 15 °C fish whereas it was significantly elevated in 20 °C group. Interestingly individual fish with high caspase 3 expression contained very low viral RNA. Thus, from our experiment, we can conclude that an effective apoptotic immune response in VHSV-infected olive flounder plays a crucial role in the survival of the host at higher temperatures. [Copyright &y& Elsevier]

Abstract: Turbot (Scophthalmus maximus) is a high-value farmed marine flatfish with growing demand and production levels in Europe susceptible to turbot-specific viral haemorrhagic septicaemia virus (VHSV) strains. To evaluate the possibility of controlling the outbreaks of this infectious disease by means of DNA vaccination, the gpG of a VHSV isolated from farmed turbot (VHSV860) was cloned into an expression plasmid containing the human cytomegalovirus (CMV) promoter (pMCV1.4-G860). In our experimental conditions, DNA immunised turbots were more than 85% protected against VHSV860 lethal challenge and showed both VHSV-gpG specific and neutralizing antibodies. To our knowledge this is the first report showing the efficacy of turbot genetic immunisation against a VHSV. Work is in progress to determine the contribution of innate and adaptive immunity to the protective response elicited by the immunization. [Copyright &y& Elsevier]

Abstract: Edwardsiella tarda is a Gram-negative broad-host-range pathogen that causes hemorrhagic septicemia in many commercially important fish species. Its ability to adapt to and thrive in diverse environments outside and inside of its hosts prompts us to investigate the roles of the previously identified 33 putative two-component signal transduction systems (TCSs) in E. tarda. In this work, we successfully constructed deletion mutations in each of the response regulator genes, suggesting that none of the TCSs are essential for cell viability in E. tarda. The mutants were further examined for roles in biofilm formation, antibiotic resistance, stress response, expression and secretion of proteins involved in either the type III secretion system (T3SS) or type VI secretion system (T6SS), as well as virulence. Through these assays, we identified four regulators of biofilm development, two regulators of antibiotic resistance, and four regulators involved in stress responses. We found that two regulators, EsrB and PhoP, are essential for the pathogenicity of E. tarda and further demonstrated that these two regulators have codependent and independent contributions to E. tarda virulence. Mutation of EsrB resulted in the complete loss of both the T3SS and T6SS proteins, while PhoP partially regulated the expression of T3SS and T6SS genes through EsrB, and was essential for resistance to antimicrobial peptides. This work suggested that these two response regulators are involved in the regulation of the complex virulence network of this bacterium and merit as candidate genes for live attenuated vaccine construction. [Copyright &y& Elsevier]

Abstract: Vibrio anguillarum is a fish pathogen that causes vibriosis, a serious hemorrhagic septicemia, in wild and cultured fish. Many serotype O1 strains of this bacterium harbor the 65kb plasmid pJM1 carrying the majority of genes encoding the siderophore anguibactin iron transport system that is one of the most important virulence factors of this bacterium. We previously identified a replication region of the pJM1 plasmid named ori1. In this work we determined that ori1 can replicate in Escherichia coli and that the chromosome-encoded proteins DnaB, DnaC and DnaG are essential for its replication whereas PolI, IHF and DnaA are not required. The copy number of the pJM1 plasmid is 1–2, albeit cloned smaller fragments of the ori1 region replicate with higher copy numbers in V. anguillarum while in E. coli we did not observe an obvious difference of the copy numbers of these constructs which were all high. Furthermore, we were able to delete the ori1 region from the pJM1 plasmid and identified a second replication region in pJM1 that we named ori2. This second replication region is located on ORF25 that is within the trans-acting factor (TAFr) region, and showed that it can only replicate in V. anguillarum. [Copyright &y& Elsevier]

An outbreak of a respiratory disease occurred in the dromedary population of Greater Cholistan desert, which was quite foreign to the locale. The duration of outbreak was more than a month (from the mid of November 2010 to the mid of December 2010). Prevalence, cumulative mortality and case fatality of outbreak were 0.79, 0.018 and 0.023, respectively. The disease was characterized by pyrexia (up to 107.4°F), severe dyspnea due to choking of nasal cavity with thick gummy material and abortion during late gestation. The disease ran a clinical course of 5-7 days. Febrile carcasses showed congestion of all visceral organs, petechial hemorrhages on the serosal surfaces, serosanguineous fluid in the thoracic and abdominal cavities and pneumonia. Postmortem findings indicated septicemia. Pasteurella multocida subsp. multocida was isolated from representative clinical and morbid specimens. Treatment trial on clinical cases indicated ciprofloxacin, ceftiofur hydrochloride, gentamicin + tylosin and thiamphenicol + tylosin to be highly efficacious. [ABSTRACT FROM AUTHOR]

Fifty-five clinical isolates of avian pathogenic Escherichia coli (APEC) from seven outbreaks of acute haemorrhagic septicaemia in turkeys were characterized by serotyping, plasmid profiling including restriction analysis with HindIII, ribotyping with EcoRI and HindIII, multilocus sequence typing (MLST) and virulence profiling. A clonal relationship was demonstrated for each outbreak according to serotype, plasmid profiling, ribotyping, and MLST. In addition, isolates demonstrated highly similar virulence profiles, as all isolates were positive for F11 pili and possessed genes encoding aerobactin (iucD), increased serum survival (iss), temperature-sensitive haemagglutinin (tsh) and colicin V plasmid operon genes (cva/cvi). However, only 20% of the isolates produced colicin V and 42% exhibited serum resistance. All strains with O group O111 and a single O18ac strain (demonstrating non-clonal DNA profiles) were positive for enteroaggregative heat-stabile toxin (EAST1), while isolates of a single outbreak all possessed the enteroaggregative toxin gene (astA). All isolates were negative for genes encoding verocytotoxins (vtx/stx), iron-repressible protein (irp2), P-fimbria (papC), invasion plasmid antigen (ipaH), attaching and effacing gene (eae), enterohaemolysin (ehxA), and enterotoxins LT, STIa (STp) and STIb (STh). In conclusion, highly similar virulence profiles were demonstrated for isolates of E. coli associated with a single well-defined lesion type of colibacillosis in turkeys; acute haemorrhagic septicaemia. The isolates obtained, however, demonstrated a different phylogenetic background, underlining the importance of using well-defined strain collections for characterization of APEC pathotypes. [ABSTRACT FROM PUBLISHER]

ABSTRACT Background and aim: Pasteurella multocida B:2, which causes hemorrhagic septicemia of ruminants, is believed to enter the host via respiratory and oral routes. While the role of respiratory route of infection has been established, the present study describes the clinical and pathological alterations following oral exposure of buffalo calves to live wild-type Pasteurella multocida B:2. Methods: Nine 8-month-old buffalo calves were selected and divided into three groups. Calves of group 1 were exposed orally to 50 mL of the inoculums containing 109 colony-forming unit (CFU)/mL of live Pasteurella multocida B:2. Calves of group 2 were exposed intra-tracheal to 5 mL of the same inoculums while calves of group 3 were exposed orally to 50 mL of phosphate-buffered saline. Results: Only one calf had to be euthanized at 48 h post-intra-tracheal exposure due to persistent clinical signs of hemorrhagic septicemia. The mean respiratory rate and rectal temperature had significantly increased in calves of groups 1 and 2. The pathological alterations included submandibular and brisket edema, generalized lymphadenopathy, acute fibrinous pneumonia, acute colitis and hemorrhagic typhilitis and proctitis. Nevertheless, oral infection with 109 CFU/mL of live wild-type P. multocida B:2 failed to produce a typical clinical disease. However, P. multocida B:2 was present along the gastro-intestinal tract, including the rectum of the calf that succumbed to the infection at 48 h post-intra-tracheal exposure. Conclusions: The presence of P. multocida B:2 along the gastro-intestinal tract is of concern since transmission via the gastro-intestinal tract of diseased animals is strongly possible. [ABSTRACT FROM AUTHOR]

Abstract: The process of “Poly(I:C) immunization” involves immunization of fish with a pathogenic live virus, followed by administration of Poly(I:C), which induces a transient, non-specific antiviral state. As a result, fish in an antiviral state survive the initial immunization with live virus. Moreover, these fish are able to mount a specific protective immune response against the injected pathogenic virus. In the present study, we investigated the optimum temperature for Poly(I:C) immunization of Japanese flounder Paralichthys olivaceus with live viral hemorrhagic septicemia virus (VHSV). It was revealed that the optimum temperature was around at 17°C for Poly(I:C) immunization in Japanese flounder. Furthermore, the protection efficacy of Poly(I:C) immunization was significantly decreased by elevation of fish rearing temperature, and no efficacy was observed at a fish rearing temperature of 25°C. Interestingly, no mortality by VHSV infection was observed in fish reared at 21°C and 25°C even when those fish were not administered Poly(I:C). All of the survivors from the first VHSV-challenge at 21°C were strongly protected from re-challenge with VHSV. However, almost all of the survivors (≥82.6%) from the first challenge at 25°C were lost by the second challenge with VHSV. It was thus concluded that by rearing fish at 21°C and challenging with live VHSV, it is possible to induce strong specific immunity in Japanese flounder without Poly(I:C) administration. [Copyright &y& Elsevier]

Vibrio anguillarum, also known as Listonella anguillarum, is the causative agent of vibriosis, a deadly haemorrhagic septicaemic disease affecting various marine and fresh/brackish water fish, bivalves and crustaceans. In both aquaculture and larviculture, this disease is responsible for severe economic losses worldwide. Because of its high morbidity and mortality rates, substantial research has been carried out to elucidate the virulence mechanisms of this pathogen and to develop rapid detection techniques and effective disease-prevention strategies. This review summarizes the current state of knowledge pertaining to V. anguillarum, focusing on pathogenesis, known virulence factors, diagnosis, prevention and treatment. [ABSTRACT FROM AUTHOR]

Movements of commodity fish present a potential risk of transferring pathogens. Within a study to estimate the risk from imported rainbow trout Oncorhynchus mykiss carcases, fry were exposed to tissue homogenates from market size rainbow trout infected experimentally with viral haemorrhagic septicaemia (VHS) by waterborne exposure to VHS virus (VHSV, isolate of genotype Ia). Tissues were collected from fish that showed clinical signs and from recent mortalities. Homogenates of (i) internal organs, (ii) brain/gills and (iii) muscle tissue were prepared and added to tanks holding the fry. Virus transmission occurred from all tissues tested, causing high mortality of the fry. The results underline the potential risk of introduction of VHSV through the trade of fish products. [ABSTRACT FROM AUTHOR]

Hemorrhagic septicemia (HS), an acute, fatal and septicemic disease of cattle and buffaloes caused by Pasteurella multocida, is important in tropical regions of the world, especially in African and Asian countries. The prevalence of disease has been well documented with predominant isolation of P. multocida serotypes B:2 and E:2. Conventional methods of identification such as serotyping, biotyping, antibiogram determination and pathogenicity as well as molecular methods (P. multocida-specific polymerase chain reaction (PCR), a serogroup B-specific PCR assay, multiplex capsular typing system and loop-mediated isothermal amplification techniques) and characterization (restriction endonuclease analysis, randomly amplified polymorphic DNA analysis, repetitive extragenic palidromic PCR and enterobacterial repetitive intergenic consensus PCR analysis) are applied in parallel for rapid epidemiological investigations of HS outbreaks. Although several vaccine formulations including alum precipitated, oil adjuvant and multiple emulsion vaccines are commercially available, the quest for suitable broadly protective HS vaccines with long-lasting immunity is on the upsurge. Concurrently, attempts are being made to unravel the mysteries of the pathogen and its virulence factors, pathogenesis and determinants of protective immunity as well as diversity among strains of P. multocida. This review highlights the advances in these various aspects of HS. [ABSTRACT FROM PUBLISHER]

A strain of bacteria was isolated from the spleen tissue of moribund Amur Sturgeon ( Acipenser schrenckii) which suffered from a hemorrhagic septicemia disease. An experimental infection model was established fulfilling the Koch's postulate. In the initial artificial infection test and the regressive infection test the typical disease symptoms were experimentally reproduced by intraperitoneal injection with isolated bacterium suspension. These symptoms were identical with those observed in naturally infected fish. The result of the infection test showed the lethal dose that killed 50% of the exposed individuals (LD) was 1.17 × 10 cfu ml. Considering the results of the Gram's staining, VITEK Bacterial Automatic Identification System, sequencing of 16S rDNA gene and phylogenetic analysis, the isolated pathogen was identified as Aeromonas hydrophila. The test on the susceptibility to antibiotics revealed that the isolated pathogen was sensitive to sensitive to Amikacin, Ciprofloxacin, Gentamicin, etc., and were resistant to Ampicilin, Sulbactam, Cefazolin, etc. [ABSTRACT FROM AUTHOR]

In an outbreak of hemorrhagic septicemia in buffalo calves in Pakistan, 31.48% mortality was recorded. Mortality significantly peaked on 8th day (37%). Elevated body temperature (40.63±0.70°C), profuse salivation, dyspnea, respiratory sound "rales", ocular discharge, mucus nasal discharge and restlessness were observed. Grossly, head, neck and inter-mandible region were congested and edematous. Subserosal petechial hemorrhages throughout the body and blood-tinged fluid in thoracic and abdominal cavities were seen. Lungs showed pneumonic changes. Kidneys were swollen and hyperemic. There were petechial hemorrhages on the epicardium. Histopathologically, extensive lung edema, emphysema, thickened alveolar septa, congestion, and edema fluid in bronchioles were observed. Kidneys exhibited glomerulus atrophy, congestion, presence of casts in tubules along with pyknosis, condensation of nuclei and necrosis of tubular epithelium. [ABSTRACT FROM AUTHOR]

Abstract: The protection conferred by antiviral DNA vaccines in fish is known to rely greatly on innate immune responses. Since oligodeoxynucleotides (ODNs) containing unmethylated CpG dinucleotides (CpG motifs) have been shown to induce potential innate immune responses, we have introduced several copies (either two or four) of a fragment containing multiple CpG sequences of known immunostimulatory effects into a DNA vaccine against viral hemorrhagic septicemia virus (VHSV). We have determined the effects of this introduction on the vaccine immunogenicity, measured as immune gene induction, serum neutralizing activity and antigen-dependent proliferation. When comparing the effects of the vaccine containing 2 copies of this CpG fragment (pVHSV-2CpG) or that containing 4 copies of the fragment (pVHSV-4CpG) with the original VHSV DNA vaccine (pVHSV), we found that the levels of expression of type I interferon (IFN) were significantly up-regulated in muscle and spleen when the CpG fragments were introduced. An up-regulation in the levels of MHC-I expression in spleen were also observed in response to the modified vaccines, whereas, the levels of transcription of interleukin 1β (IL-1β) were strongly reduced in comparison to the original vaccine. Important but very variable differences were also observed concerning the vaccine induction of IFN-γ. Moreover, the serum neutralizing capacity was strongly increased as fish were vaccinated with plasmids containing more CpG fragments. Taken together, all these results demonstrate a strongly increased immunogenicity of the VHSV DNA vaccine, through the introduction of this multicopy CpG fragment. [ABSTRACT FROM AUTHOR]

Surface de-adhesion and disinfection of eggs at hatcheries are critical steps in successful fry culture; however, little is known about the effects of the combination of these compounds on the efficacy of egg surface disinfection. We examined the effect of tannic acid on detection of viral hemorrhagic septicemia virus (VHSV) type IVb alone and in the presence of iodophor under in vitro conditions. We confirmed that tannic acid inhibits the quantitative reverse-transcriptase polymerase chain reaction assay developed in our laboratory and that it binds to VHSV, reversibly decreasing infectivity. Surprisingly, we also found that when combined with iodophor, tannic acid destroys the ability of either compound to inhibit infectivity. While we still strongly encourage the use of iodophor for its antiviral, bactericidal, and fungicidal properties, our results suggest that when tannic acid is used prior to disinfection with iodophor, it must be very thoroughly rinsed to ensure that it does not interfere with the disinfectant properties of iodophor. [ABSTRACT FROM AUTHOR]

Abstract: Zebrafish were used to investigate the expression levels of several antiviral and inflammatory genes (IL-1β, iNOS, TNF-α, TLR3, IFN-I, IFNγ, IRF3, MDA-5, Mx) constitutively and after viral stimulation during early development. We also determined how their expression was affected by changes in the temperature. The antiviral genes were almost completely inhibited at 15°C with the exception of TLR3. In contrast, IL-1β, iNOS and TNF-α expression was not obviously different between the two temperatures. At 15°C, most of the genes examined did not differ following stimulation with poly I:C or viral hemorrhagic septicemia virus (VHSV). However, at 28°C, all of the genes showed significant differences in at least some of the sampling points after poly I:C treatment with the largest differences observed for Mx. Mx expression in adult zebrafish was not significantly altered by temperature and poly I:C treatment led to a smaller increase in gene expression when compared to larval Mx levels. Thus, Mx seems to play an important role in viral immunity in larvae, when the adaptive immune response is not fully functional. [ABSTRACT FROM AUTHOR]

With the recent emphasis on funding and training opportunities for global health and humanitarian aid and the increased interest in the field, many health care workers and medical researchers are traveling from resource-replete to resource-limited settings. This type of travel brings unique disease risks not routinely considered for the business or vacationing traveler. This review provides practical advice for this special population of travelers, targeted to specific health care-related risks (needlestick, hemorrhagic fever viruses, severe viral respiratory disease, and tuberculosis), with suggestions for risk mitigation. [ABSTRACT FROM AUTHOR]

The recently identified type VI secretion system (T6SS) is implicated in the virulence of many Gram-negative bacteria. Edwardsiella tarda is an important cause of hemorrhagic septicemia in fish and also gastro- and extra-intestinal infections in humans. The E. tarda virulent protein (EVP) gene cluster encodes a conserved T6SS which contains 16 open reading frames. EvpC is one of the three major EVP secreted proteins and shares high sequence similarity with Hcp1, a key T6SS virulence factor from Pseudomonas aeruginosa. EvpC contributes to the virulence of E. tarda by playing an essential role in functional T6SS. Here, we report the crystal structure of EvpC from E. tarda PPD130/91 at a 2.8 Å resolution, along with functional studies of the protein. EvpC has a β-barrel domain with extended loops. The β-barrel consists of 11 anti-parallel β-strands with an a-helix located on one side. In solution, EvpC exists as a dimer at low concentration and as a hexamer at higher concentration. In the crystal, the symmetry related EvpC molecules form hexameric rings which stack together to form a tube similar to Hcp1. Structure based mutagenesis revealed that N-terminal negatively charged residues, Asp4, Glu15 and Glu26, and C-terminal positively charged residues, Lys161, Lys162 and Lys163, played crucial roles in the secretion of EvpC. Moreover, the localization study indicates the presence of wild type EvpC in cytoplasm, periplasm and secreted fractions, whereas the N-terminal and C-terminal mutants were found mostly in the periplasmic region and was completely absent in the secreted fraction. Results reported here provide insight into the structure, assembly and function of EvpC. Further, these findings can be extended to other EvpC homologs for understanding the mechanism of T6SS and targeting T6SS mediated virulence in Gram-negative pathogens. [ABSTRACT FROM AUTHOR]

This study was undertaken for the evaluation of efficacy of hypertonic saline solution (HSS) in combination with ceftiofur HCl and flunixin meglumine (FM) in septicemic pasteurellosis in buffaloes. For this purpose, 50 buffaloes suffering from septicemic pasteurellosis were selected from the field and randomly divided into two equal groups (A and B). Group A served as control and treated with ceftiofur HCl, IM and flunixin meglumine, IV @ 6 and 2 mg/kg BW, respectively. While buffaloes of group B were administered with rapid intravenous infusion of hypertonic saline solution (7.5% NaCl) @ 4 ml/kg BW followed by normal saline solution @ 10 ml/kg BW along with ceftiofur HCl and flunixin meglumine. Treatments were started after application of cold water on head for 15 minutes. Ceftiofur HCl and flunixin meglumine were repeated after 12, 24 and 48 hours in both the groups. Animals were then monitored for 24 hours after initiation of treatment. Haematological parameters, serum electrolytes and serum biochemical profiles were measured at baseline, 1, 3, 6, 12 and 24 hours after treatment and survival index was recorded at interval of one week. The survival percent was 50 and 80 amongst animals treated respectively with protocol A and B, respectively. In terms of reduction of severity of disease, group B showed significant difference (P < 0.05) over group A. The treatment protocol B exploiting the use of hypertonic saline solution in combination with cephalosporin (ceftiofur HCl) plus a non-steroidal antiinflammatory drug (flunixin meglumine) was more effective than the conventional treatment i.e. ceftiofur HCl and flunixin meglumine alone for the treatment of haemorrhagic septicaemia. It was concluded from the study that administration of hypertonic saline solution in combination with ceftiofur HCl and flunixin meglumine has beneficial effects in the treatment of haemorrhagic septicaemia in buffaloes. [ABSTRACT FROM AUTHOR]

The present study was planed to determine the effect of prophylactic application of levamisole in hemorrhagic septicemia (HS) vaccinated buffalo calves. For this purpose sixty 5 month old buffalo-calves were randomly selected from Livestock Production Research Institute Bhadurnagar (LPRI) Okara, Pakistan. These calves were divided into three equal groups viz; G1, G2 and G3. Animals in G1 group received 3ml (I/M) injection of HS bacterin (Oil based NAIB,HS vaccine) while animals in G2 received levamisole @0.5mg/kg body weight two days prior to HS bacterin (Oil based NAIB,HS vaccine) administration (3ml,I/M) and group G3 served as nonvaccinated and nonmedicated control. The antibody titers against Pasteurella multocida was measured by Indierct Haemagglutination (IHA) test. The evaluation criteria included Geometric Mean Titer (GMT) and Lymphocytes Proliferation Assay (LPA). The values of GMT titers were significantly higher (P>0.05) in G2 group (21.5) as compared to that of G1 (14.79) and G3 (2.5) groups. Lymphocytes Proliferation Assay (LPA) values were significantly higher in G2 group (0.317±0.041) than that of G1 (0.049±0.003) and G3 (0.043±0.002) groups. The results of present study indicated that prophylactic application of levamisole helps in achieving efficient immunization in buffalo calves. [ABSTRACT FROM AUTHOR]

The article discusses a study on a monoclonal antibody against viral haemorrhagic septicaemia virus (VHSV) genotype IVa that was developed for the establishment of immunochemical methods to discriminate genotype IVa from other VHSV genotypes. Viral haemorrhagic septicaemia (VHS) is a disease of Oncorhynchus mykiss rainbow trout in Europe. The procedure of the study was comprised of several steps including immunization of mice, cell fusion, and immunoglobin class determination. It was found that the monoclonal antibody (MAb) VHS-10 recognizes a nonlinear genotype IVa-specific epitope on the VHSV N-protein.

Pasteurella multocida B:2 is an etiological agent of hemorrhagic septicemia in cattle and buffaloes. It is commonly fatal and considered as one of the most economically important cattle diseases in Southeast Asia. This study describes the pathological changes in the lungs of calves following intra-tracheal challenge with wild-type P. multocida B:2. For this purpose, six calves of 8-month old were selected and divided into two groups of 3 calves. Calves of Group 1 were challenged with intra-tracheal 5ml inoculum containing 109 cfu/ml of wild-type P. multocida B:2, while the calves of Group 2 were similarly administered with PBS. All the challenged calves of Group 1 showed slight dullness and were found to be inactive within 72 hours after inoculation, but none died. Meanwhile, their lungs showed petechiations and patches of acute pneumonia affecting few lobules. Histological examinations revealed the presence of haemorrhages into the alveoli, whereas some sections showed thickened inter-alveolar septa due to congestion and the presence of neutrophils. However, pulmonary oedema was absent. P. multocida B:2 was successfully isolated from all the calves of Group 1. [ABSTRACT FROM AUTHOR]

Background: Immune function after hemorrhagic shock and subsequent sepsis is characterized by an early proinflammatory burst of IL-6, and high IL-6 levels have been linked to high mortality after trauma and in sepsis. Trans-signaling is defined as the activation of cells that do not express the membrane bound IL-6 receptor by the complex of IL-6 and the soluble IL-6 receptor (sIL-6R). Gp130-Fc is able to bind the IL-6/sIL-6R complex, and beneficial effects of IL-6 blockade in chronic inflammatory diseases have been shown. The first aim of this study was to investigate the potential effect of a gp130 blockade via the gp130-Fc antibody causing impairment of IL-6 signaling. The second aim was to find out what role the IL-6/sIL-6R complex can play in the context of hemorrhagic shock and subsequent sepsis as an acute inflammatory disease. Material and Methods: Male CBA/J mice were subjected to hemorrhagic shock (35±5 mmHg for 90min and fluid resuscitation) or sham operation. At resuscitation each animal received either 0.5mg gp130-Fc or placebo (PL) i.p. At 48 h after resuscitation, both splenocytes and peritoneal macrophages (pMφ) were harvested or polymicrobial sepsis was induced by cecal ligation and puncture. Survival over 10 d was determined. Release of IL-6, TNF-α, and IL-10 of pMφ and release of IL-2, IL-10, and IFN-γ of splenocytes was assessed by ELISA. Proliferation of splenocytes and their morphologic damage were determined. Results: Binding of the IL-6/sIL-6R complex by gp130-Fc led to significant lower IL-6 levels compared with placebo treated animals. Placebo treated males showed depressed proinflammatory immune response (IL-2, IL-6) after hemorrhagic shock. While splenocyte proliferation was significantly reduced directly after hemorrhagic shock and restored after 48 h by gp130-Fc, pMφ cytokine release was not influenced. Finally, survival appeared to be unaffected. Conclusion: Transsignaling does not seem to play a pivotal role in the development of the immune dysfunction and mortality in our model of hemorrhage and subsequent sepsis. [Copyright &y& Elsevier]

Abstract: Pasteurellosis is one of the most prevalent diseases of sheep, but the involvement of Pasteurellae in genital pathology of rams has been described rarely. One hundred and eighty-four rams showing palpable lesions in testes, epididymides or scrotum were submitted to bacteriological studies, and seven mature rams found infected with bacterial species belonging to the Pasteurella cluster (i.e., Mannheimia, Pasteurella and Bibersteinia (M/P/B)). The M/P/B cultures obtained were pure and/or heavy, and were confirmed after necropsy in the five M/P/B infected rams that could be slaughtered for further pathological examinations. Pasteurella multocida infected rams exhibited fibrinous exudate and generalized adhesions between the vaginal and the external scrotal layers. Testicular atrophy and epididymal sperm granulomas were also evident in these rams. Microscopically, epithelial hyperplasia with intraepithelial cysts, fibrosis and spermatic granulomas were present in the epididymis, while testis showed sperm stasis foci, microcalcifications and fibrosis. Mannheimia haemolytica infected rams showed severe unilateral epididymitis and testicular atrophy, being microscopically similar to the lesions found in P. multocida infected rams. The ram found infected with B. threalosi had severe unilateral lesions in testis, epididymis and scrotum. Microscopically, abscesses in epididymis and testis, and severe fibrosis and interstitial round cells infiltrates in testis were observed. Further studies should be conducted to determine properly the role played by the Pasteurella cluster in the pathogenesis of genital lesions in rams. [Copyright &y& Elsevier]

In this study 60 local calves breed (30 animals of with otitis externa and 30 without otitis externa) of both sexes, three weeks to six months old were examined clinically and bacteriologically for isolaltion and identification of the bacterial agents from external otic canal. The main clinical signs observed in animals with otitis externa included auricular discharge (unilateral in 23 and bilateral in 7 calves), cough, nasal discharge, anorexia, and emaciation. Results revealed isolation of (9) bacterial species from external otic canal in both calves with otitis externa and without otitis externa. The predominant species found in calves with otitis externa were Pasteurella multocida, Mannheimia hemolytica and Staphylococcus aureus, while in the calves without otitis externa were Escherichia coli, Klebsiella pneumonia, and Staphylococcus epidermis. Results also indicated that the most bacterial isolated from calves with otitis externa were resistance to the bactericidal effect of the calf normal serum and produced hydroxymate siderophore in comparison with bacterial isolated from calves without otitis externa. [ABSTRACT FROM AUTHOR]

Abstract: Pasteurella multocida serotype B:2 is the causative agent of haemorrhagic septicaemia (HS), a fatal disease of cattle and buffaloes. As a step towards the identification of individual antigens that may protect against HS, proteins present in a sonicated cell extract (SCE) and outer-membrane protein (OMP) preparation of a wild-type P. multocida serotype B:2 were investigated by immunoblotting with sera from calves which had been protected against challenge with a virulent strain of P. multocida B:2 by vaccination with a live-attenuated aroA derivative of the challenge strain. Five proteins in SCE, of approximately 50, 37, 30, 26 and 16kDa, were recognised by the sera. In an OMP preparation, two bands, at 37 and 50kDa, were recognised as strongly immunogenic. Mass spectrometry analysis of proteins corresponding in size to those detected by immunoblotting identified the 37kDa band as OmpA, but the band at 50kDa was not identified with certainty. A major 30kDa OMP, identified as OmpH, was not strongly immunogenic. [Copyright &y& Elsevier]