Virulence of the Nine Serovar Reference Strains of Haemophilus paragallinarum

Soriano, V. E.; Longinos, G. M.; Fernandez, Rachel; Velásquez, Quiroz; Ciprían, C. A.; Salazar-García, F.; Blackall, P. J.

doi:10.1637/7188-033104r1

Cited by 32 publications

(13 citation statements)

References 8 publications

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“…paragallinarum isolates from Uganda are pathogenic to chickens, in agreement with other reports of isolates from elsewhere (Page, 1962;Reid & Blackall, 1984;Sawata et al ., 1985b;Lin et al ., 1996;Bragg, 2002a;Soriano et al, 2004). Using disease scores described by Bragg (2002b), there was no significant variation in the virulence between the isolates in chickens.…”

Section: Discussionmentioning

confidence: 96%

“…It was observed that transformation of the wild-type NAD-dependent serovar C-3 to a NAD-independent variant also decreased its virulence (Taole et al, 2002). Soriano et al (2004) demonstrated variations among the nine reference serovars of the three serogroups of Av. paragallinarum , with serovar C-1 being more virulent.…”

Section: Discussionmentioning

confidence: 99%

“…paragallinarum , although major differences have been reported among the nine serovars of the three serogroups of Av. paragallinarrum (Soriano et al, 2004). A few studies have investigated the association of the characteristics of Av.…”

Section: Introductionmentioning

confidence: 99%

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Virulence characterization ofAvibacterium paragallinarumisolates from Uganda

Byarugaba

Minga²,

Gwakisa

et al. 2007

Avian Pathology

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Avibacterium paragallinarum isolates from Uganda were characterized for their virulence by comparison of their pathogenicity and their resistance to serum. Pathogenicity was evaluated using commercial Hisex Brown layer chickens, local indigenous chickens, local turkeys and local guineafowls inoculated with 108 colony-forming units of Av. paragallinarum and comparing their overall mean disease scores over a period of 20 days. Persistence of the bacteria in the host and water was also investigated for a 60-day period by culture and polymerase chain reaction as well as use of sentinel chickens. Serum resistance was measured by comparison of the growth kinetics and survival indices at 3 and 6 h. There was no difference in the virulence of the isolates. Commercial layer chickens and local indigenous chickens were equally susceptible to challenge, while turkeys and guineafowls only showed transient mild signs and did not transmit infection. Turkeys and guineafowls did not acquire the infection when placed in contact with infected chickens. The isolates were resistant in normal chicken serum at both 3 and 6 h of incubation but were resistant at 3 h and sensitive at 6 h in turkey and guineafowl sera. The resistance of the isolates to serum correlated with their pathogenicity in the different hosts. No carrier status was demonstrated in this study using polymerase chain reaction and culture. The present study demonstrates that Ugandan Av. paragallinarum isolates are pathogenic to chickens with only transient signs in turkeys and guineafowls, and that serum resistance could be a subject for further investigation as a predictor of virulence of these bacteria. The role of turkeys and guineafowls in transmission of Av. paragallinarum was not demonstrated in the present investigation.

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Section: Discussionmentioning

confidence: 96%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Virulence characterization ofAvibacterium paragallinarumisolates from Uganda

Byarugaba

Minga²,

Gwakisa

et al. 2007

Avian Pathology

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“…Each bird was examined for clinical signs by three experienced observers and the score given to each bird was agreed unanimously by all three observers. The mean daily clinical signs score was calculated as previously reported (22) and differences in the scores were compared using the Student's t-test. Seven days after the challenge, infraorbital sinus swabs from chickens were streaked onto a BHI agar plate supplemented with 5% bovine serum and 0.01% NAD.…”

Section: Methodsmentioning

confidence: 99%

The Fimbrial Protein is a Virulence Factor and Potential Vaccine Antigen ofAvibacterium paragallinarum

Liu

Tan

et al. 2016

Avian Diseases

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Fimbriae are recognized as virulence factors and potential vaccine antigens of several pathogenic bacteria, but the function of the fimbriae from Avibacterium paragallinarum is not well known. In this study, a gene encoding the fimbrial protein FlfA was identified in A. paragallinarum . Sequencing analysis of the putative promoter region of flfA suggests that flfA expression in A. paragallinarum might be controlled by phase variation. The flfA gene from A. paragallinarum was expressed as a recombinant protein (r-FlfA) in Escherichia coli . Immunization with r-FlfA conferred chickens protection against challenge infection with A. paragallinarum . Virulence assays showed that the flfA-deficient mutants of A. paragallinarum were less virulent than their parental wild-type strains. These results indicated that the fimbrial protein FlfA is a virulence factor and potential vaccine antigen from A. paragallinarum .

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“…Infectious coryza (ICR) is an acute respiratory disease of chicken caused by Haemophilus paragallinarum, a Gram-negative bacterium (Blackall et al 2005;Blackall 1999). ICR induces nasal and lacrimal discharges, facial swelling, and diarrhea reducing the growth and egg production in chicken (Han et al 2016;Soriano et al 2004). Although ICR induces very high morbidity, it has about 1.6% CFR in chicken in Nepal.…”

Section: Infectious Coryzamentioning

confidence: 99%