scholarly journals Chlamydia gallinacea: genetically armed as a pathogen however a phenotypical commensal?

2020 ◽  
Author(s):  
Marloes Heijne ◽  
Martina Jelocnik ◽  
Alexander Umanets ◽  
Michael S.M. Brouwer ◽  
Annemieke Dinkla ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Clinical Signs ◽  
Chlamydia Psittaci ◽  
Pathogenic Potential ◽  
Animal Pathogens ◽  
The Family ◽  
Chicken Eggs ◽  
Sequence Types ◽  
Embryonated Chicken ◽  
Infection Experiments

AbstractChlamydia gallinacea is an obligate intracellular bacterium that has recently been added to the family of Chlamydiaceae. C. gallinacea is genetically diverse, widespread in poultry and a suspected cause of pneumonia in slaughterhouse workers. In poultry, C. gallinacea infections appear asymptomatic, but studies about the pathogenic potential are limited. In this study two novel sequence types of C. gallinacea were isolated from apparently healthy chickens. Both isolates (NL_G47 and NL_F725) were closely related to each other and showed 99.1% DNA sequence identity to C. gallinacea Type strain 08-1274/3. To gain further insight in the pathogenic potential, infection experiments in embryonated chicken eggs and comparative genomics with Chlamydia psittaci were performed. C. psittaci is an ubiquitous zoonotic pathogen of birds and mammals, and infection in poultry can result in severe systemic illness. In experiments with embryonated chicken eggs C. gallinacea induced mortality was observed, potentially strain dependent but lower compared to C. psittaci induced mortality. Comparative analyses confirmed all currently available C. gallinacea genomes possess the hallmark genes coding for known and potential virulence factors as found in C. psittaci albeit to a reduced number of orthologues or paralogs. The presence of (potential) virulence factors and the observed mortality in embryonated eggs indicates C. gallinacea should rather be considered as a (conditional) pathogen than an innocuous commensal.ImportanceChlamydiaceae are a family of bacteria comprising human and animal pathogens including the recently recognized Chlamydia gallinacea. C. gallinacea is widespread in poultry without causing clinical signs, which raises questions about its pathogenic potential. To assess this potential, two novel C. gallinacea strains were isolated, tested in infection experiments in embryonated chicken eggs and compared to C. psittaci. C. psittaci infection in poultry can result in severe systemic illness, depending on the conditions, and infections can be transmitted to humans. In the experiments C. gallinacea infection induced mortality of the embryo, but to a lower extent than infection with C. psittaci. Subsequent genome comparisons confirmed both C. gallinacea strains possess potential virulence genes typical for chlamydia, but fewer than C. psittaci. These results indicate C. gallinacea does have a pathogenic potential which warrants further research to elucidate its role as a poultry pathogen.

scholarly journals Genetic and phenotypic analysis of the pathogenic potential of two novel Chlamydia gallinacea strains compared to Chlamydia psittaci

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marloes Heijne ◽  
Martina Jelocnik ◽  
Alexander Umanets ◽  
Michael S. M. Brouwer ◽  
Annemieke Dinkla ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Opportunistic Pathogen ◽  
Chlamydia Psittaci ◽  
Phenotypic Analysis ◽  
Pathogenic Potential ◽  
The Family ◽  
Chicken Eggs ◽  
Sequence Types ◽  
Insight Into ◽  
Embryonated Chicken

AbstractChlamydia gallinacea is an obligate intracellular bacterium that has recently been added to the family of Chlamydiaceae. C. gallinacea is genetically diverse, widespread in poultry and a suspected cause of pneumonia in slaughterhouse workers. In poultry, C. gallinacea infections appear asymptomatic, but studies about the pathogenic potential are limited. In this study two novel sequence types of C. gallinacea were isolated from apparently healthy chickens. Both isolates (NL_G47 and NL_F725) were closely related to each other and have at least 99.5% DNA sequence identity to C. gallinacea Type strain 08-1274/3. To gain further insight into the pathogenic potential, infection experiments in embryonated chicken eggs and comparative genomics with Chlamydia psittaci were performed. C. psittaci is a ubiquitous zoonotic pathogen of birds and mammals, and infection in poultry can result in severe systemic illness. In experiments with embryonated chicken eggs, C. gallinacea induced mortality was observed, potentially strain dependent, but lower compared to C. psittaci induced mortality. Comparative analyses confirmed all currently available C. gallinacea genomes possess the hallmark genes coding for known and potential virulence factors as found in C. psittaci albeit to a reduced number of orthologues or paralogs. The presence of potential virulence factors and the observed mortality in embryonated eggs indicates C. gallinacea should rather be considered as an opportunistic pathogen than an innocuous commensal.

scholarly journals Molecular epidemiology and phylogenomic analysis of Mycobacterium abscessus clinical isolates in an Asian population

2021 ◽  
Vol 7 (11) ◽  
Author(s):  
Ka Lip Chew ◽  
Sophie Octavia ◽  
Roland Jureen ◽  
Oon Tek Ng ◽  
Kalisvar Marimuthu ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Type Species ◽  
Asian Population ◽  
Bioinformatic Analysis ◽  
Mycobacterium Abscessus ◽  
Phylogenomic Analysis ◽  
Pathogenic Potential ◽  
Content Type ◽  
Link Type ◽  
Sequence Types

Mycobacterium abscessus comprises three subspecies: M. abscessus subsp. abscessus , M. abscessus subsp. bolletii , and M. abscessus subsp. massiliense . These closely related strains are typically multi-drug-resistant and can cause difficult-to-treat infections. Dominant clusters of isolates with increased pathogenic potential have been demonstrated in pulmonary infections in the global cystic fibrosis (CF) population. An investigation was performed on isolates cultured from an Asian, predominantly non-CF population to explore the phylogenomic relationships within our population and compare it to global M. abscessus isolates. Whole-genome-sequencing was performed on M. abscessus isolates between 2017 and 2019. Bioinformatic analysis was performed to determine multi-locus-sequence-type, to establish the phylogenetic relationships between isolates, and to identify virulence and resistance determinants in these isolates. A total of 210 isolates were included, of which 68.5 % (144/210) were respiratory samples. These isolates consisted of 140 (66.6 %) M . abscessus subsp. massiliense , 67 (31.9 %) M . abscessus subsp. abscessus, and three (1.4 %) M . abscessus subsp. bolletii . Dominant sequence-types in our population were similar to those of global CF isolates, but SNP differences in our population were comparatively wider despite the isolates being from the same geographical region. ESX (ESAT-6 secretory) cluster three appeared to occur most commonly in ST4 and ST6 M. abscessus subsp. massiliense , but other virulence factors did not demonstrate an association with isolate subspecies or sample source. We demonstrate that although similar predominant sequence-types are seen in our patient population, cross-transmission is absent. The risk of patient-to-patient transmission appears to be largely limited to the vulnerable CF population, indicating infection from environmental sources remains more common than human-to-human transmission. Resistance and virulence factors are largely consistent across the subspecies with the exception of clarithromycin susceptibility and ESX-3.

Control of African Swine Fever and Avian Spirochaetosis

2021 ◽  
pp. 329-353
Author(s):  
Charles Muleke Inyagwa ◽  
Erick O. Mungube
Keyword(s):  
Life Cycle ◽  
Clinical Signs ◽  
African Swine Fever ◽  
Economic Importance ◽  
Morphological Features ◽  
Historical Background ◽  
Direct Damage ◽  
Animal Pathogens ◽  
The Family ◽  
Veterinary Importance

Ticks are distributed worldwide and have an enormous medical and veterinary importance owing to the direct damage they cause and indirectly as vectors of a large variety of human and animal pathogens. The family Argasidae (soft ticks) comprises five genera and with about 193 species. Among all the argasid ticks, only four Argas and two Ornithodoros species are competent to transmit diseases. This chapter describes the various ticks of the argasidae family, diseases they transmit, and strategies for their control. A description of the two important genera, Ornithodorus and Argas, that belong to the family argasidae are provided. Emphasis is on the mammalian hosts affected, tick species involved, morphological features (with relevant pictorials), geographic distribution, life cycle, and economic importance. A detailed description of the two most important diseases transmitted by argasidae ticks namely African swine fever (ASF) and avian spirochaetosis is given. Emphasis is laid on the historical background, epidemiology, clinical signs, and strategies for their control.

scholarly journals Characterisation of some Ornithobacterium rhinotracheale strains and examination of their transmission via eggs

2001 ◽  
Vol 49 (2) ◽  
pp. 125-130 ◽  
Author(s):  
J. Varga ◽  
L. Fodor ◽  
L. Makrai
Keyword(s):  
Clinical Signs ◽  
Polymyxin B ◽  
Penicillin G ◽  
Post Inoculation ◽  
Biochemical Characteristics ◽  
High Concentrations ◽  
Egg Shell ◽  
Chicken Eggs ◽  
Embryonated Chicken ◽  
Ornithobacterium Rhinotracheale

The biochemical characteristics and antibiotic susceptibility of 12 Ornithobacterium rhinotracheale strains isolated from chickens and turkeys suffering from respiratory clinical signs and the survival of some isolates on egg-shell and within chicken eggs during hatching were examined. All O. rhinotracheale strains showed typical biochemical characteristics. Among the 16 drugs examined, penicillin G, ampicillin (MICs ranging from ≤ 0.06 μg/ml to 1 μg/ml), ceftazidim (with MICs from ≤ 0.06 μg/ml to 0.12 μg/ml), erythromycin, tylosin, tilmicosin (with some exceptions MICs ranged from ≤ 0.06 μg/ml to 1 μg/ml) and tiamulin (MICs varied from ≤ 0.06 μg/ml to 2 μg/ml) were the most effective. Lincomycin, oxytetracycline and enrofloxacin also gave good inhibitions, but with most strains in a higher concentration (MICs ranged in most cases from 2 μg/ml to 8 μg/ml). The other antibiotics inhibited the growth of O. rhinotracheale only in very high concentrations (colistin) or not at all (apramycin, spectinomycin, polymyxin B). At 37 °C, O. rhinotracheale did not survive on egg-shell for more than 24 hours, while upon inoculation into embryonated chicken eggs it killed embryos by the ninth day, and from the 14th day post-inoculation no O. rhinotracheale could be cultured from the eggs at all. These results suggest that O. rhinotracheale is not transmitted via eggs during hatching.

scholarly journals Teratogenicity of the Palyam serogroup orbiviruses in the embryonated chicken egg model

1991 ◽  
Vol 106 (1) ◽  
pp. 179-188 ◽  
Author(s):  
T. Whistler ◽  
R. Swanepoel
Keyword(s):  
Statistical Analysis ◽  
Yolk Sac ◽  
Serological Tests ◽  
Pathogenic Potential ◽  
Chicken Egg ◽  
Congenital Deformities ◽  
Teratogenic Potential ◽  
Chicken Eggs ◽  
Virus Isolates ◽  
Embryonated Chicken

SUMMARYEmbryonated chicken eggs were used as a model for assessing the teratogenic potential of several Palyam serogroup orbiviruses. Infection of 4-day-old embryonated chicken eggs via the yolk sac with eight of the viruses resulted in deaths or congenital deformities which included retarded development, arthrogryposis and reduced feathering. Statistical analysis showed that the viruses could be divided into three groups: those that caused death (Gweru virus isolates 866/77 and 1726/7776 and Apies River virus), those that caused deaths only when large amounts of virus were inoculated (Gweru isolate AR11869 and Marondera virus) and those that caused death and deformities (Abadina, Kasba, Nyabira, Petevo and Vellore viruses). Differences in pathogenic potential were noted between isolates identified as the same serotype by serological tests.

scholarly journals Susceptibility of various animals to the vesiculoviruses Isfahan and Chandipura

1986 ◽  
Vol 97 (2) ◽  
pp. 359-368 ◽  
Author(s):  
C. R. Wilks ◽  
J. A. House
Keyword(s):  
Clinical Signs ◽  
Neutralizing Antibody ◽  
Post Inoculation ◽  
Serum Samples ◽  
Pathogenic Potential ◽  
Adult Mice ◽  
Antibody Titres ◽  
The Right ◽  
Chicken Eggs ◽  
Old Mice

SummaryTo determine the pathogenic potential of the vesiculoviruses Isfahan Chandipura for domestic animals, two ponies, two steers, three and three pigs were inoculated with each virus intradermally in the tongue or, in the case of the pigs, in the snout, heel and coronary band The Ponies were also inoculated intradcrmally in the right commissure o the mouth Animals inoculated with each virus were housed in one room and allowed to mingle freely with an equal number of uninoculated contact animals of each species.Clinical signs of infection, consisting of ulcers at the inoculation sites, were observed in the Chandipura study in two inoculated ponies, one inoculated steer and one inoculated goat. No elevated temperature was observed. Virus was isolated from the ulcerated tongue tissue but not from serial blood samples, oesophagcal-pharyngeal mucus samples, or from the tissues which were collected at necropsy. Precipitating antibody was not detected by the immunoelectro osmophoresis(IEOP) test in any of the pre- or post-serum samples except from two inoculated sheep at 29 days post-inoculation (D.P.I.). Low levels of neutralizing activity were dtedted in pre-inoculation serum from all steers, pigs, contact sheep, and one contact goa. By 15 D.P.I. all inoculated animals and contact ponies and steers exhibited increased neutralizing antibody titres.In studies with the Isfahan virus, lesions developed only at the inoculation sites in the two ponies, and the virus was isolated. No virus was isolated from any blood, oesophageal-pharyngeal mucus samples or tisues collected at necropsy. All pre-inoculation sera were negative for neutralizing and precipitating antibodies. By 14 D.P.I. all inoculated animals exhibited neutralizing antibody, while all the contacts remained negative. The IEOP test remained negative for all animals throughout the experiment. A subpassage of a suspension of Isfahan-infected tongue tissue injected in to ponies and steers also yielded only firm swellings of lesser extent than the original reaction at the inoculation sites.With both viruses, lethal infections were produced by intraacranial or intraperitoneal inoculation of day-old mice and hamsters, and by allantoic inoculation of embryonating chicken eggs. Adult mice, hamsters, guinea-pigs and rabbits produced serum antibodies but lacked clinical signs.

scholarly journals Susceptibility of various animals to the vesiculovirus Piry

1984 ◽  
Vol 93 (1) ◽  
pp. 147-155 ◽  
Author(s):  
C. R. Wilks ◽  
J. A. House
Keyword(s):  
Elevated Temperature ◽  
Adult Female ◽  
Specific Antibody ◽  
Clinical Signs ◽  
Neutralizing Antibody ◽  
Domestic Animals ◽  
Post Inoculation ◽  
Pathogenic Potential ◽  
Vesicular Stomatitis ◽  
Chicken Eggs

SUMMARYTo determine the pathogenic potential of the vesiculovirus Piry for domestic animals, two ponies, two steers, three sheep, three goats and three pigs were inoculated intradermally in the tongue or, in the case of the pigs, in the snout, heel and coronary band. Inoculated animals were housed in one room and allowed to mingle freely with an equal number of uninoculated contact animals of each species. Clinical signs of infection, consisting of elevated temperature and ulcers at the inoculation sites, were only observed in the ponies, but all inoculated animals developed specific antibody following inoculation. In addition, one of the contact sheep had neutralizing antibody to Piry at 7 and 29 days post inoculation suggesting a contact infection. Virus was not demonstrated in tissues, other than tongue, of any animal.The failure of Piry virus to produce lesions in steers, sheep, goats and pigs and only limited ulcerations in ponies suggests that this virus is not similar pathogenically to New Jersey and Indiana strains of vesiculoviruses which produce classical vesicular stomatitis.Lethal infections were produced by inoculation into suckling mice and hamsters, adult hamsters and embryonating chicken eggs. Further, lethal infections followed contact of adult female hamsters with their inoculated litters.

scholarly journals Pathogenicity, Epidemiology and Virulence Factors of Salmonella species: A Review

2017 ◽  
Vol 9 (4) ◽  
pp. 460-466 ◽  
Author(s):  
Tamègnon Victorien DOUGNON ◽  
Boris LEGBA ◽  
Esther DEGUENON ◽  
Gildas HOUNMANOU ◽  
Jerrold AGBANKPE ◽  
...  
Keyword(s):  
Public Health ◽  
Virulence Factors ◽  
Meat Products ◽  
Health Problems ◽  
Molecular Techniques ◽  
Salmonella Spp ◽  
Salmonella Infections ◽  
The Family ◽  
The World ◽  
Salmonella Control

Salmonella infections are major public health problems worldwide. The hereby review aimed to establish an overview on the pathogenicity, epidemiology and virulence factors of Salmonella spp. in the world. A systematic search was conducted online using the keywords ‘Salmonella’, ‘Salmonella spp.’, ‘Salmonella spp. Epidemiology’, ‘virulence factors of Salmonella spp. in the world’, ‘bacteria responsible for the contamination of meat products’, ‘non-typhoid salmonella’. These keywords were entered into databases such as PubMed and Google Scholar using mainly French language. The obtained articles were included based on the reliability of their source, the study area (usually Benin and Africa) and the subject. The review revealed that Salmonella spp. is motile Gram-negative rod-shaped bacteria, of the family Enterobacteriaceae, currently counting more than 2,600 serovars. Human contamination occurs through the ingestion of contaminated water and food and can cause gastroenteritis or typhoid fever, which are two serious public health problems. A gene set constituting the pathogenicity islands determines the pathogenesis of Salmonella spp. The diagnosis is based on bacteriological, serological and molecular techniques. Salmonella infections are usually treated using antibiotics; however, emergence of antibiotic resistance in these microorganisms suggests that the anti-salmonella control should explore new sources such as medicinal plants

scholarly journals Simplified Method for Efficient Intravascular Inoculation of Chicken Embryos

1976 ◽  
Vol 4 (1) ◽  
pp. 104-105
Author(s):  
C. L. Kelling ◽  
I. A. Schipper
Keyword(s):  
Vascular Trauma ◽  
Chicken Embryos ◽  
Simplified Method ◽  
Chicken Eggs ◽  
Embryonated Chicken ◽  
Embryonic Death

The simple syringe-stabilizer unit described in this note provides a means for rapid intravascular inoculation of embryonated chicken eggs with minimal embryonic death from vascular trauma.

Vaccine Production

2021 ◽  
Author(s):  
Frederick Porter
Keyword(s):  
Cultured Cells ◽  
Animal Cell ◽  
Infectious Agents ◽  
Vaccine Production ◽  
Expression Systems ◽  
Subunit Vaccines ◽  
Gene Vectors ◽  
Viral Vaccines ◽  
Chicken Eggs ◽  
Embryonated Chicken

Introduction Vaccines are biological products that elicit a protective immune response. The details of the manufacturing processes are varied depending on the particular characteristics of the vaccine. There are classically, three basic types of vaccines against viral and bacterial pathogens (For mRNA-, DNA- and vector-vaccines see Chapters 7, 8, 9): Live-attenuated. Killed (non-live). Subunit. “Classical” Vaccine Production The basic classical process includes 5 phases: expression, harvest, inactivation, purification, formulation. The expression systems for viral and bacterial vaccines are distinct. Bacterial expression is performed in fermenters. Viral vaccines are produced in animal cell culture or embryonated chicken eggs. Processes for whole viral or bacterial vaccines often involve only limited processing after expression. Subunit vaccines routinely require the most purification to separate the product from other contaminants. Challenges Challenges for bacterial vaccines include testing to ensure the safety and efficacy of the product. Inactivation procedures need to be carefully controlled. Live attenuated vaccines need to be tested to ensure the vaccine strains are still safe and effective. Viral vaccines require testing to ensure foreign infectious agents are not introduced during processing. Both cultured cells and egg present risks for infection. Live viral vaccines and gene vectors need to be carefully engineered and tested to minimize safety concerns. Highly variable vaccine targets such as influenza need to be re-adapted to current circulating strains.

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