Biological characterization of Pasteurella multocida present in the Saiga population.

BACKGROUND: This study provides biochemical and molecular genetic characteristics of P. multocida isolated from dead saigas in 1988, 2010-2015 on the territory of the Republic of Kazakhstan. RESULTS: Bacteriological samples taken from carcasses of saiga antelope during mortality events recorded in West Kazakhstan in both 2010 and 2011 and in Kostanay in 2012 and 2015 confirmed the presence of P. multocida, according to morphological and biochemical characterisation. Only in the event of 2015 was the agent proven to be the causative agent of the disease observed, haemorrhagic septicaemia. In the other mortality events it is not certain if the organism was a primary aetiology or an incidental finding as confirmatory pathological investigation was not undertaken. The implemented phylogenetic analysis of ribosomal RNA 16S gene allowed us to identify Pasteurella strains isolated in 2010-2015 as P. multocida subspecies multocida. Capsular typing by PCR showed that the studied strains isolated from dead saiga in 2010, 2011, 2012 and 2015 belonged to serotype B. MLST analysis showed that these strains of P. multocida are of the capsule type B and form one clonal grouping with isolates ST64, ST44, ST45, ST46, ST44, ST47 which isolated from cases of hemorrhagic septicemia of animals in Hungary, Burma, Sri Lanka, Pakistan and Spain. Sixteen virulence genes of the five strains of P. multocida, isolated from saigas were studied using multiplex PCR. ptfA, ompA, ompH, oma87, plpB, fimA, hsf-2, pfhA, exbB, tonB, hgbA, fur, nanB, nanH and pmHAS genes were detected in all strains. The toxA gene was not identified in the studied strains. The phylogenies of these isolates is compared across saiga populations and years and the 2015 isolate was compared to that of an isolate from a disease outbreak in 1988 and the findings suggest that these isolated bacteria are stable commensals, opportunistically pathogenic, being phylogenetically uniform with very little genetic variation notable over the last 4 decades. CONCLUSION: Isolation, phenotypic and genetic characterization of the P. multocida isolates inform understanding of the epidemiology of infection in saigas and predict virulent potential of these opportunistic bacteria.

Bacteremia in cirrhotic patients with upper gastrointestinal bleeding.

BACKGROUND/AIMS: Increased risk of bacterial infection is common in cirrhotic patients with upper gastrointestinal bleeding (UGIB). Our study aimed to explore the association of the bacteremia with in-hospital mortality and risk factors of bacteremia in these patients. MATERIALS AND METHODS: In our retrospective cohort study, we collected data for cirrhotic patients with UGIB admitted to our hospital between August 2010 and December 2010. The primary outcome was in-hospital mortality. The secondary outcome was bacteremia. A multivariate logistic regression analysis was performed to determine risk factors for mortality and bacteremia. RESULTS: A total of 202 patients with cirrhosis presenting with UGIB at the emergency department (ED) were enrolled. Bacteremia was associated with a higher mortality rate (adjusted odds ratio [OR]: 9.7; 95% confidence interval [CI]: 1.9-50.6, p=0.007), whereas shock (systolic blood pressure <90 mmHg at ED triage) and bandemia (>0% immature neutrophils of band form) were associated with bacteremia in cirrhotic patients with UGIB (adjusted OR: 5.3; 95% CI: 2.3-12.7, p<0.0001 and adjusted OR: 4.0; 95% CI: 1.6-9.9, p=0.0003, respectively). CONCLUSION: Bacteremia in cirrhotic patients with UGIB is one of the major risk factors leading to in-hospital mortality. On the basis of our findings, prevention of bacteremia in cirrhotic patients with UGIB, especially in those with shock and bandemia, is important; thus, adequate antibiotic treatment is suggested.

Mouse model of haemorrhagic septicaemia: dissemination and multiplication of Pasteurella multocida B:2 in vital organs after intranasal and subcutaneous challenge in mice.

Haemorrhagic septicaemia (HS) is an endemic disease of bovines, occurring in most tropical regions of Asia and Africa. In the present study, the suitability of using mice to study pathogenesis of HS was assessed using mortality, mean death time and bacterial multiplication in vital organs after infection with live P multocida. Mice were infected with 10(5), 10(3) and 10(1)cfu of P. multocida B:2 via intranasal and subcutaneous routes along with control groups. Bacterial multiplication in lung, liver and spleen of mice were determined at 24 h interval after intranasal and subcutaneous challenge. More than 80 % of challenged mice died within 48 h of inoculation, irrespective of the dose and route of inoculation. A heavy bacterial load (up to 10(8)cfu) was observed in lung, liver and spleen of mice titrated at 24 h and following death of mice. Results of the present study indicate that even ten bacteria are enough to cause mortality in mice and the organism multiplies rapidly in respiratory epithelium and disseminated to other vital organs viz liver and spleen suggesting the important role of mouse model in investigating the pathogenesis and challenge studies during vaccine development.

Construction and characterization of a live, attenuated esrB mutant of Edwardsiella tarda and its potential as a vaccine against the haemorrhagic septicaemia in turbot, Scophthamus maximus (L.).

The esrB gene of Edwardsiella tarda, which encodes a regulator protein of the type III secretion system, was mutated by the unmarked deletion method and reintroduced by allelic exchange into the chromosome of E. tarda LSE40 by means of the suicide vector pRE112. The LSE40 esrB mutant was highly attenuated when inoculated intraperitoneally into turbot Scophthamus maximus L., showing a 50% lethal dose of 10(8.1)cfu/fish. The esrB mutants were not recoverable from the internal organs at 14 days post-inoculation. Vaccination with a single dose of 10(5)-10(7) cfu/fish of the esrB mutant elicited significant protection against the wild-type strain of E. tarda LSE40 (relative percentage survival>50%). The protection correlated well with the antibody titres in the serum of vaccinated fish.

Community perceptions of important camel diseases in Lapur Division of Turkana District, Kenya.

This paper presents the results of a study conducted in Lapur Division of Turkana District, Kenya, to estimate the incidence and mortality of camel trypanosomosis using participatory methods. Four livestock camps ('adakars') were conveniently selected for the study. Four informant groups comprising 6 8 key persons were used for the participatory exercises. The camel diseases identified by the pastoralists in their order of importance according to annual incidence were: trypanosomosis (11.4%); mange (10.8%); tick infestation (7.9%); haemorrhagic septicaemia (7.7%); and non-specific diarrhoea (7.6%). Almost half (49.3%) of the camel population suffered from at least one disease over the previous year. The annual incidence and mortality rates of trypanosomosis were estimated at 15%, and 9.9%, in adult camels and 6.9% and 5.2%, in young camels, respectively. There was a seasonal occurrence of trypanosomosis, with most cases reported in the dry season. The prevalence levels of the disease reportedly declined from about 100%, in 1978 to an almost stable state of about 15% in 2002. This study revealed that camel trypanosomosis is still an important disease in Turkana District, exacting a heavy toll in terms of morbidity and mortality. The economic losses due to the disease were likely to have been great owing to the central role the camel plays in this arid district of Kenya.

Efficacy of vaccination of calves against hemorrhagic septicemia with a live aroA derivative of Pasteurella multocida B:2 by two different routes of administration.

Two groups of four calves each were immunized either intramuscularly (i.m. vaccinated) or intranasally (i.n. vaccinated) at 2 and 6 weeks of age with ca. 10(9) CFU of a derivative of P. multocida serotype B:2 strain 85020 containing a deletion in the aroA gene (strain JRMT12). Both groups of calves and three unvaccinated control calves were challenged subcutaneously at 8 weeks of age with ca. 10(7) CFU of the wild-type 85020 strain. The first and second vaccinations caused a significant pyrexia and increase in the mean demeanor score (P <0.05) in i.m. but not i.n. vaccinated calves. Serum agglutinating activity against whole cells of P. multocida strain 85020 and immunoglobulin G antibody concentrations increased after the second vaccination in i.m. but not in i.n. vaccinated animals, and this difference was statistically significant (P <0.05). Concentrations of serum amyloid A (SAA) increased significantly 3 h after both the primary (P <0.05) and booster (P <0.001) i.m. vaccinations, but not in i.n. vaccinated calves. All four i.m. vaccinated calves were solidly immune to challenge with wild-type P. multocida B:2. However, the mean rectal temperatures, demeanor scores, and serum SAA concentrations of i.n. vaccinated and control calves increased significantly (P <0.01). Three i.n. vaccinated and two control calves were killed for humane reasons within 14 h postchallenge, and postmortem examination revealed pathological lesions consistent with hemorrhagic septicemia. These data showed that the aroA mutant strain, given i.m. as two doses 4 weeks apart, acted as an effective live-attenuated vaccine strain to protect calves against challenge with the virulent parent strain.

Septicemic pasteurellosis in elk (Cervus elaphus) on the United States National Elk Refuge, Wyoming.

Septicemic pasteurellosis caused by Pasteurella multocida is believed responsible for the deaths of 48 elk (Cervus elaphus) on the National Elk Refuge near Jackson, Wyoming (USA) during 1986 and 1987. Clinical signs included depression and salivation; necropsy findings included congestion and petechial and ecchymotic hemorrhages in lymph nodes, diaphragm, lungs and endocardium. Pasteurella multocida was isolated from femur marrow of eight carcasses and a variety of tissues from eight others.

Mortality among cattle and buffaloes in Sri Lanka due to haemorrhagic septicaemia.

Data on the mortality of cattle and buffaloes in 62 epizootics of haemorrhagic septicaemia (HS) in the HS enzootic and non-enzootic regions of Sri Lanka was collected and subjected to statistical analysis. It was found that the overall mortality for buffaloes was higher than for cattle (45.2 and 15.8% respectively, P less than 0.001). For buffaloes in enzootic areas only the overall mortality was 29% whilst in non-enzootic areas it was 64.5% (P less than 0.05). In the enzootic areas deaths were mainly confined to young animals whereas in the non-enzootic areas when sporadic outbreaks of HS occurred deaths were scattered over all age groups. The vaccines used, vaccination schedules adopted and the coverage of vaccination in these herds did not appear to influence the mortality among buffaloes in enzootic areas to a statistically significant degree.