scholarly journals OBTAINING A GENETIC ATTENUATED AROA MUTANT STRAIN PASTEURELLA MULTOCIDA

Author(s):  
N.K. Dalbaev ◽  
D.N. Kaysenov ◽  
K.T. Sultankulova ◽  
E.T. Taylakova ◽  
O.V. Chervyakova ◽  
...  
Vaccine ◽  
1997 ◽  
Vol 15 (2) ◽  
pp. 203-208 ◽  
Author(s):  
Preecha Homchampa ◽  
Richard A. Strugnell ◽  
Ben Adler

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Zui Wang ◽  
Li Li ◽  
Peng Liu ◽  
Chen Wang ◽  
Qin Lu ◽  
...  

Abstract Background Pasteurella multocida is responsible for a highly infectious and contagious disease in birds, leading to heavy economic losses in the chicken industry. However, the pathogenesis of this disease is poorly understood. We recently identified an aspartate ammonia-lyase (aspA) in P. multocida that was significantly upregulated under iron-restricted conditions, the protein of which could effectively protect chicken flocks against P. multocida. However, the functions of this gene remain unclear. In the present study, we constructed aspA mutant strain △aspA::kan and complementary strain C△aspA::kan to investigate the function of aspA in detail. Result Deletion of the aspA gene in P. multocida resulted in a significant reduction in bacterial growth in LB (Luria-Bertani) and MH (Mueller-Hinton) media, which was rescued by supplementation with 20 mM fumarate. The mutant strain △aspA::kan showed significantly growth defects in anaerobic conditions and acid medium, compared with the wild-type strain. Moreover, growth of △aspA::kan was more seriously impaired than that of the wild-type strain under iron-restricted conditions, and this growth recovered after supplementation with iron ions. AspA transcription was negatively regulated by iron conditions, as demonstrated by quantitative reverse transcription-polymerase chain reaction. Although competitive index assay showed the wild-type strain outcompetes the aspA mutant strain and △aspA::kan was significantly more efficient at producing biofilms than the wild-type strain, there was no significant difference in virulence between the mutant and the wild-type strains. Conclusion These results demonstrate that aspA is required for bacterial growth in complex medium, and under anaerobic, acid, and iron-limited conditions.


2004 ◽  
Vol 32 (02) ◽  
pp. 88-91
Author(s):  
Susanne Kloß ◽  
A. Wehrend ◽  
Astrid König ◽  
H. Bostedt

Zusammenfassung: Gegenstand und Ziel: Im Gegensatz zur Hündin liegen bei der Katze bisher wenige Studien über die genitale Keimflora geschlechtsgesunder Tiere vor. Ziel der Untersuchung war daher, physiologische Daten über die aerobe Vaginalflora bei dieser Spezies zu gewinnen. Material und Methoden: Für die vorliegende Studie standen 26 gesunde, anöstrische Katzen zur Verfügung, die zu einer Ovariohysterektomie vorgestellt wurden. Nach einer klinischen Untersuchung wurden von allen Probanden unter sterilen Bedingungen Vaginaltupfer entnommen. Ergebnisse: In allen Proben konnte ein Bakterienwachstum mit durchschnittlich zwei verschiedenen Bakterienspezies nachgewiesen werden. Die Gesamtkeimgehalte wurden bei 50% der Vaginaltupferproben als gering-, bei 15% als mittel- und bei 35% als hochgradig beurteilt. Vorherrschend waren Mischkulturen aus zwei bis vier verschiedenen Keimarten. Monokulturen wurden aus 38% der Tupferproben isoliert. Am häufigsten gelang der Nachweis von E. coli variatio haemolytica (E. coli var. haem.) (58%) und Staphylococcus epidermidis (42%). Als weitere Spezies wurden E. coli, α-, β-hämolysierende Streptokokken, anhämolysierende Streptokokken, aerobe Bazillen, Staphylococcus aureus, Staphylococcus intermedius, Pasteurella multocida sowie Klebsiellen isoliert. Auffällig ist die hohe Nachweisrate von E. coli var. haem. mit 35% in Mischkulturen und 23% in Reinkultur. Schlussfolgerungen: Die physiologische Mikroflora der felinen Vaginalschleimhaut differiert deutlich von der der anöstrischen Hündin. Besonders die Dominanz von E. coli var. haem. in 38% der Mischkulturen und 23% der Monokulturen bei der Katze ist hervorzuheben. Klinische Relevanz: Die vorliegenden Ergebnisse geben eine erste Grundlage für die Interpretation mikrobiologischer Befunde feliner Vaginaltupfer.


2007 ◽  
Vol 34 (S 2) ◽  
Author(s):  
D Anhuf ◽  
T Klockgether ◽  
A Hartmann

2018 ◽  
Vol 24 (1) ◽  
Author(s):  
SHAMIM AKHTER CHOUDHARY

In the present study, an attempt was made to study the effect of plant extract on Sexual behaviour of Mutant Strain (Curled) of Drosophila melanogaster. The LC50 has been estimated with 1% of the food media. The virgin females and males were isolated and fed with normal food media for three days. Then sub-lethal concentrations of 0.625 μl / 100 ml food, 1.2 μl /100 ml food, 2.5μl /100 / food of nicotine were mixed in food medium and allowed in flies to feed for two days. Then appropriate combination of untreated / treated males and females were introduced into the mating chamber. Courtship latency, mating latency and copulation duration were studied. After observation of the behaviour, mated flies were allowed to produce progeny. The sexual behaviour of bachelor male and virgin female obtained in the progeny was also studied. The pooled data were analyzed by student t-test and the result indicates p-value significant at 0.05 levels. The courtship latency was affected by in treatment but it is neither dose dependent nor sex dependent.


2003 ◽  
Author(s):  
Charles Thomas Parker ◽  
Dorothea Taylor ◽  
George M Garrity

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