scholarly journals Molecular serotyping of clinical strains ofHaemophilus (Glaesserella) parasuisbrings new insights regarding Glässer’s disease outbreaks in Brazil

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6817 ◽  
Author(s):  
Julia Pires Espíndola ◽  
Natalia Balbinott ◽  
Letícia Trevisan Gressler ◽  
Gustavo Machado ◽  
Catia Silene Klein ◽  
...  
Keyword(s):  
Infectious Disease ◽  
Disease Outbreaks ◽  
Whole Cell ◽  
Prevention Of Infection ◽  
Molecular Serotyping ◽  
Glässer’S Disease ◽  
Polysaccharide Capsule ◽  
Capsule Locus ◽  
Specific Polysaccharide ◽  
Glasser's Disease

Glässer’s disease (GD) is an important infectious disease of swine caused byHaemophilus (Glaesserella) parasuis. Vaccination with inactivated whole cell vaccines is the major approach for prevention ofH. parasuisinfection worldwide, but the immunity induced is predominantly against the specific polysaccharide capsule. As a consequence, the available vaccines may not induce adequate protection against the field strains, when the capsules present in the vaccine strains are different from those in strains isolated from the farms. Therefore, it is crucial to mapH. parasuisserovars associated with regional outbreaks so that appropriate bacterin vaccines can be developed and distributed for prevention of infection. In this study, 459H. parasuisfield strains isolated from different Glässer’s disease outbreaks that occurred in 10 different Brazilian States were analyzed for serotype using PCR-based approaches. Surprisingly, non-typeable (NT) strains were the second most prevalent group of field strains and along with serovars 4, 5 and 1 comprised more than 70% of the isolates. A PCR-based approach designed to amplify the entire polysaccharide capsule locus revealed 9 different band patterns in the NT strains, and 75% of the NT strains belonged to three clusters, suggesting that a number of new serovars are responsible for a substantial proportion of disease. These results indicate that commercially available vaccines in Brazil do not cover the most prevalentH. parasuisserovars associated with GD.

scholarly journals Development and Characterization of ProtectiveHaemophilus parasuisSubunit Vaccines Based on Native Proteins with Affinity to Porcine Transferrin and Comparison with Other Subunit and Commercial Vaccines

2010 ◽  
Vol 18 (1) ◽  
pp. 50-58 ◽  
Author(s):  
Rafael Frandoloso ◽  
Sonia Martínez ◽  
Elías F. Rodríguez-Ferri ◽  
María José García-Iglesias ◽  
Claudia Pérez-Martínez ◽  
...  
Keyword(s):  
Outer Membrane Proteins ◽  
Lethal Dose ◽  
Clinical Signs ◽  
Disease Outbreaks ◽  
Haemophilus Parasuis ◽  
Histopathological Changes ◽  
Native Proteins ◽  
Glässer’S Disease ◽  
Glasser's Disease

ABSTRACTHaemophilus parasuisis the agent responsible for causing Glässer's disease, which is characterized by fibrinous polyserositis, polyarthritis, and meningitis in pigs. In this study, we have characterized native outer membrane proteins with affinity to porcine transferrin (NPAPT) fromH. parasuisserovar 5, Nagasaki strain. This pool of proteins was used as antigen to developed two vaccine formulations: one was adjuvanted with a mineral oil (Montanide IMS 2215 VG PR), while the other was potentiated with a bacterial neuraminidase fromClostridium perfringens. The potential protective effect conferred by these two vaccines was compared to that afforded by two other vaccines, consisting of recombinant transferrin-binding protein (rTbp) A or B fragments fromH. parasuis, Nagasaki strain, and by a commercially available inactivated vaccine. Five groups of colostrum-deprived piglets immunized with the vaccines described above, one group per each vaccine, and a group of nonvaccinated control animals were challenged intratracheally with a lethal dose (3 × 108CFU) ofH. parasuis, Nagasaki strain. The two vaccines containing rTbps yielded similar results with minimal protection against death, clinical signs, gross and microscopic lesions, andH. parasuisinvasion. In contrast, the two vaccines composed of NPAPT antigen and commercial bacterin resulted in a strong protection against challenge (without deaths and clinical signs), mild histopathological changes, and no recovery ofH. parasuis, thus suggesting their effectiveness in preventing Glässer's disease outbreaks caused by serovar 5.

scholarly journals Development of Serotype-Specific PCR Assays for Typing of Haemophilus parasuis Isolates Circulating in Southern China

2017 ◽  
Vol 55 (11) ◽  
pp. 3249-3257 ◽  
Author(s):  
Aiqing Jia ◽  
Ruyue Zhou ◽  
Huiying Fan ◽  
Kaijie Yang ◽  
Jianmin Zhang ◽  
...  
Keyword(s):  
Southern China ◽  
Disease Outbreaks ◽  
Specific Method ◽  
Haemophilus Parasuis ◽  
Content Type ◽  
Specific Pcr ◽  
Glässer’S Disease ◽  
Serotype 5 ◽  
Pcr Assays ◽  
Glasser's Disease

ABSTRACTThe bacteriumHaemophilus parasuisis the specific pathogenic cause of Glässer's disease in swine. Fifteen serotypes ofH. parasuishave been reported. A method to serotypeH. parasuisisolates accurately would help to prevent and control Glässer's disease outbreaks through appropriate vaccination and to understand the epidemiology in specific geographic areas. However, according to traditional serotyping, the rate of nontypeable (NT) strains is 10 to 40%, which gives low accuracy. In the present study, we developed a set of PCR assays that are able to identify all the currently knownH. parasuisserotypes, with a detection limit of 5 CFU. This PCR method is particularly useful to distinguish serotype 5 from serotype 12. We then surveyed the serotype prevalence ofH. parasuisisolates from southern China using both the traditional indirect hemagglutination (IHA) and current PCR methods. Of the 298 isolates tested, 228 (76.51%) and 281 (94.30%) were serotyped by the IHA and PCR tests, respectively, with a concordance rate of 80.87% (241/298). The most prevalent serotypes obtained by PCR were 4, 5, 12, 13, NT, and 2, and the most prevalent obtained by IHA were NT, 5, 4, 12, 13, and 2. In conclusion, the PCR assays developed in this study provide a rapid and specific method for the molecular serotyping ofH. parasuis.

scholarly journals Molecular serotyping ofHaemophilus parasuisisolated from diseased pigs and the relationship between serovars and pathological patterns in Taiwan

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e6017 ◽  
Author(s):  
Wei-Hao Lin ◽  
Hsing-Chun Shih ◽  
Chuen-Fu Lin ◽  
Cheng-Yao Yang ◽  
Yung-Fu Chang ◽  
...  
Keyword(s):  
Vaccine Development ◽  
Economic Losses ◽  
Respiratory Syndrome Virus ◽  
Swine Industry ◽  
Vaccination Programs ◽  
Polysaccharide Biosynthesis ◽  
Molecular Serotyping ◽  
Glässer’S Disease ◽  
Glasser's Disease ◽  
The Relationship

BackgroundHaemophilus parasuisis the etiological agent of Glässer’s disease, and causes severe economic losses in the swine industry. Serovar classification is intended as an indicator of virulence and pathotype and is also crucial for vaccination programs and vaccine development. According to a polysaccharide biosynthesis locus analysis,H. parasuisisolates could be classified by a molecular serotyping assay except serovars 5 and 12 detected by the same primer pair. The aim of this study was to identifyH. parasuisisolates from diseased pigs in Taiwan by using a molecular serotyping assay and to analyze the relationship between serovars and pathological patterns.MethodsFrom August 2013 to February 2017, a total of 133 isolates from 277 lesions on 155 diseased animals from 124 infected herds serotyped by multiplex PCR and analyzed with pathological data.ResultsThe dominant serovars ofH. parasuisin Taiwan were serovars 5/12 (37.6%), 4 (27.8%) and 13 (15%) followed by molecular serotyping non-typable (MSNT) isolates (13.5%). Nevertheless, the serovar-specific amplicons were not precisely the same sizes as previously indicated in the original publication, and MSNT isolates appeared with unexpected amplicons or lacked serovar-specific amplicons. MostH. parasuisisolates were isolated from nursery pigs infected with porcine reproductive and respiratory syndrome virus. The percentage of lung lesions (30.4%) showingH. parasuisinfection was significantly higher than that of serosal lesions.DiscussionCollectively, the distribution of serovars in Taiwan is similar to that found in other countries, but MSNT isolates remain due to genetic variations. Furthermore, pulmonary lesions may be optimum sites forH. parasuisisolation, the diagnosis of Glässer’s disease, and may also serve as points of origin for systemicH. parasuisinfections in hosts.

scholarly journals Infectious disease outbreaks in the African region: overview of events reported to the World Health Organization in 2018

2019 ◽  
Vol 147 ◽  
Author(s):  
F. Mboussou ◽  
P. Ndumbi ◽  
R. Ngom ◽  
Z. Kassamali ◽  
O. Ogundiran ◽  
...  
Keyword(s):  
Infectious Disease ◽  
Disease Onset ◽  
Disease Outbreaks ◽  
Case Fatality ◽  
World Health ◽  
African Region ◽  
Regional Office ◽  
Member States ◽  
Infectious Disease Outbreaks ◽  
The World

Abstract The WHO African region is characterised by the largest infectious disease burden in the world. We conducted a retrospective descriptive analysis using records of all infectious disease outbreaks formally reported to the WHO in 2018 by Member States of the African region. We analysed the spatio-temporal distribution, the notification delay as well as the morbidity and mortality associated with these outbreaks. In 2018, 96 new disease outbreaks were reported across 36 of the 47 Member States. The most commonly reported disease outbreak was cholera which accounted for 20.8% (n = 20) of all events, followed by measles (n = 11, 11.5%) and Yellow fever (n = 7, 7.3%). About a quarter of the outbreaks (n = 23) were reported following signals detected through media monitoring conducted at the WHO regional office for Africa. The median delay between the disease onset and WHO notification was 16 days (range: 0–184). A total of 107 167 people were directly affected including 1221 deaths (mean case fatality ratio (CFR): 1.14% (95% confidence interval (CI) 1.07%–1.20%)). The highest CFR was observed for diseases targeted for eradication or elimination: 3.45% (95% CI 0.89%–10.45%). The African region remains prone to outbreaks of infectious diseases. It is therefore critical that Member States improve their capacities to rapidly detect, report and respond to public health events.

scholarly journals 478. Psychological Distress among Infectious Disease Physicians during the Response to the COVID-19 Outbreak in the Republic of Korea

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S305-S305
Author(s):  
Se Yoon Park ◽  
Bongyoung Kim ◽  
Dong Sik Jung ◽  
Sook In Jung ◽  
Won Sup Oh ◽  
...  
Keyword(s):  
Infectious Disease ◽  
Psychological Distress ◽  
Infection Control ◽  
Personal Protective Equipment ◽  
Text Message ◽  
Disease Outbreaks ◽  
Maslach Burnout Inventory ◽  
Republic Of Korea ◽  
Protective Equipment ◽  
The Republic

Abstract Background This study aimed to investigate psychological distress among infectious disease (ID) physicians during the coronavirus disease (COVID-19) outbreak in the Republic of Korea. Methods Using an online-based survey link sent via text message and email, we conducted a survey from April 21 to 25, 2020, targeting all ID physicians currently working in ID (n = 265). The questionnaire was based on the Maslach Burnout Inventory-Human Services Survey and the Depression, Anxiety, and Stress Scales, and information was collected on factors protecting against psychological distress and difficulties in relation to COVID-19. Results Of 265 ID physicians, 115 (43.3%) responded, showing burnout (97, 90.4%), depression (20, 17.4%), anxiety (23, 20.0%), and stress (5, 4.3%). There were no differences in terms of distress between ID physicians who were directly involved in the care of patients with COVID-19 or not (Table 1). Greater than 50% of physicians valued their work and felt recognized by others, whereas < 10% indicated that sufficient human and financial support and private time had been provided during the outbreak. The most challenging issues concerned a lack of human resources for COVID-19 treatment or infection control, a shortage of personal protective equipment or airborne infection isolation rooms, pressure for research, and lack of guidelines for COVID-19 management (Figure 1). Table 1. Figure 1. Difficulties in response to the COVID-19 outbreak. Abbreviations: COVID-19, coronavirus disease 19; HCWs, healthcare workers; ICPs, infection control practitioners; IRB, Institutional Review Board; PPE, personal protective equipment Conclusion During the COVID-19 outbreak in the ROK, most respondents reported psychological distress. Preparing strategies for infectious disease outbreaks that support ID physicians is essential. Disclosures All Authors: No reported disclosures

Improvements to a PCR-Based Serogrouping Scheme for Salmonella enterica from Dairy Farm Samples

2015 ◽  
Vol 78 (6) ◽  
pp. 1182-1185 ◽  
Author(s):  
JEFFREY S. KARNS ◽  
BRADD J. HALEY ◽  
JO ANN S. VAN KESSEL
Keyword(s):  
Salmonella Enterica ◽  
Dairy Farm ◽  
Disease Outbreaks ◽  
In Silico Analysis ◽  
Pcr Assay ◽  
Molecular Serotyping ◽  
Reverse Primer ◽  
Pcr Method ◽  
Silico Analysis

Molecular serotyping through the use of PCR is a simple and useful technique for characterizing isolates of Salmonella enterica subsp. enterica belonging to serogroups B, C1, C2, D1, and E1, which are the majority of the isolates associated with human disease outbreaks. However, many of the Salmonella strains currently isolated from dairy farms in the northeastern United States are serovar Cerro, a group K strain not detected by this assay. Primers from a well-known PCR assay for the identification of Salmonella were added to a commonly used serotyping assay so that strains, such as Salmonella Cerro, that do not produce bands in the original assay can be confirmed as belonging to S. enterica subsp. enterica. The modified assay frequently misidentified the serogroup of Salmonella Mbandaka isolates because of failure to amplify the wzxC1 amplicon. Therefore, the reverse primer for the wzxC1 target was modified based on in silico analysis to provide consistent classification of Salmonella Mbandaka as belonging to serogroup C1. These two modifications to the serogrouping PCR method enhance the utility of the method for characterizing Salmonella isolates.

scholarly journals Statistical methods for the prospective detection of infectious disease outbreaks: a review

2011 ◽  
Vol 175 (1) ◽  
pp. 49-82 ◽  
Author(s):  
Steffen Unkel ◽  
C. Paddy Farrington ◽  
Paul H. Garthwaite ◽  
Chris Robertson ◽  
Nick Andrews
Keyword(s):  
Infectious Disease ◽  
Statistical Methods ◽  
Disease Outbreaks ◽  
Infectious Disease Outbreaks
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