Haemophilus paragallinarum
Haemophilus
Pasteurellaceae
Haemophilus influenzae
Haemophilus ducreyi
Pasteurella
Bird Diseases
Haemophilus Vaccines
Genetic analysis of a plasmid encoding haemocin production in Haemophilus paragallinarum. (1/4)
The full sequence of plasmid p250, isolated from Haemophilus paragallinarum strain HP250, has been obtained. The plasmid contains seven ORFs: a putative integrase, a putative replication protein (repB) and five ORFs similar to those from the haemocin (bacteriocin) hmcDCBAI operon from Haemophilus influenzae. Of 19 other non-plasmid-containing H. paragallinarum strains screened (11 serovar reference strains and 8 field isolates), 17 strains produced haemocin and were resistant to killing by strain HP250. These strains, unlike strain HP250, have a chromosomally encoded haemocin operon. A number of other members of the family Pasteurellaceae were tested for haemocin sensitivity. Pasteurella avium, Pasteurella volantium and Pasteurella species A, all non-pathogenic bacteria found in the respiratory tract of chickens suffering from respiratory diseases, were sensitive to H. paragallinarum haemocin. However, amongst the pathogenic Pasteurellaceae, 50 % of P. multocida isolates and all five isolates of Pasteurella haemolytica tested were sensitive to the haemocin. Given the prevalence of haemocin production in H. paragallinarum strains, it may play a role in aiding colonization by inhibiting other Gram-negative bacteria that are associated with the respiratory tract in chickens. The origin of replication from plasmid p250 has been used to generate an Escherichia coli-H. paragallinarum shuttle vector which may be useful in genetically manipulating H. paragallinarum. (+info)Reclassification of Pasteurella gallinarum, [Haemophilus] paragallinarum, Pasteurella avium and Pasteurella volantium as Avibacterium gallinarum gen. nov., comb. nov., Avibacterium paragallinarum comb. nov., Avibacterium avium comb. nov. and Avibacterium volantium comb. nov. (2/4)
This paper describes a phenotypic and genotypic investigation of the taxonomy of [Haemophilus] paragallinarum, Pasteurella gallinarum, Pasteurella avium and Pasteurella volantium, a major subcluster within the avian 16S rRNA cluster 18 of the family Pasteurellaceae. An extended phenotypic characterization was performed of the type strain of [Haemophilus] paragallinarum, which is NAD-dependent, and eight NAD-independent strains of [Haemophilus] paragallinarum. Complete 16S rRNA gene sequences were obtained for one NAD-independent and four NAD-dependent [Haemophilus] paragallinarum strains. These five sequences along with existing 16S rRNA gene sequences for 11 other taxa within avian 16S rRNA cluster 18 as well as seven other taxa from the Pasteurellaceae were subjected to phylogenetic analysis. The analysis demonstrated that [Haemophilus] paragallinarum, Pasteurella gallinarum, Pasteurella avium and Pasteurella volantium formed a monophyletic group with a minimum of 96.8 % sequence similarity. This group can also be separated by phenotypic testing from all other recognized and named taxa within the Pasteurellaceae. As both genotypic and phenotypic testing support the separate and distinct nature of this subcluster, the transfer is proposed of Pasteurella gallinarum, [Haemophilus] paragallinarum, Pasteurella avium and Pasteurella volantium to a new genus Avibacterium as Avibacterium gallinarum gen. nov., comb. nov., Avibacterium paragallinarum comb. nov., Avibacterium avium comb. nov. and Avibacterium volantium comb. nov. The type strains are NCTC 1118T (Avibacterium gallinarum), NCTC 11296T (Avibacterium paragallinarum), NCTC 11297T (Avibacterium avium) and NCTC 3438T (Avibacterium volantium). Key characteristics that separate these four species are catalase activity (absent only in Avibacterium paragallinarum) and production of acid from galactose (negative only in Avibacterium paragallinarum), maltose (negative only in Avibacterium avium) and mannitol (negative in Avibacterium gallinarum and Avibacterium avium). (+info)Prevalence of Actinobacillus pleuropneumoniae, Actinobacillus suis, Haemophilus parasuis, Pasteurella multocida, and Streptococcus suis in representative Ontario swine herds. (3/4)
Tonsillar and nasal swabs were collected from weanling pigs in 50 representative Ontario swine herds and tested for the presence of 5 important bacterial upper respiratory tract pathogens. All but 1 herd (2%) tested positive for Streptococcus suis by polymerase chain reaction (PCR); 48% of herds were S. suis serovar 2, 1/2 positive. In all but 2 herds there was evidence of Haemophilus parasuis infection. In contrast, toxigenic strains of Pasteurella multocida were detected by a P. multocida--enzyme-linked immunosorbant assay (PMT-ELISA) in only one herd. Seventy-eight percent of the herds were diagnosed positive for Actinobacillus pleuropneumoniae by apxIV PCR. Sera from finishing pigs on the same farms were also collected and tested by ELISA for the presence of A. pleuropneumoniae antibodies. Seventy percent of the herds tested had evidence of antibodies to A. pleuropneumoniae including serovars 1-9-11 (2%), 2 (4%), 3-6-8-15 (15%), 5 (6%), 4-7 (26%), and 12 (17%). This likely represents a shift from previous years when infection with A. pleuropneumoniae serovars 1, 5, and 7 predominated. At least 16% and possibly as many as 94% of the herds tested were Actinobacillus suis positive; only 3 of the 50 herds were both A. pleuropneumoniae and A. suis negative as judged by the absence of a positive PCR test for apxII. Taken together, these data suggest that over the past 10 years, there has been a shift in the presence of pathogenic bacteria carried by healthy Ontario swine with the virtual elimination of toxigenic strains of P. multocida and a move to less virulent A. pleuropneumoniae serovars. As well, there appears to be an increase in prevalence of S. suis serovar 2, 1/2, but this may be a reflection of the use of a more sensitive detection method. (+info)Development of a multiplex PCR and PCR-RFLP method for serotyping of Avibacterium paragallinarum. (4/4)
Avibacterium (Haemophilus) paragallinarum (A. paragallinarum) is a causative agent of infectious coryza in chickens and is classified into three serovars by agglutination tests. In an effort to identify the serovars easily, PCR and PCR-RFLP were employed. As the target gene for PCR, the hypervariable region of HMTp210, which encodes the HA antigen, was used. PCR using primer sets around the hypervariable region amplified 0.8, 1.1 and 1.6 kbp fragments for serovars A, B and C, respectively. Alternatively, the 1.6 kbp fragments were amplified with another primer pair encompassing the hypervariable region and was subjected to digestion with Bgl II, which resulted in the detection of serovar-specific digestion patterns. These results indicate that PCR and PCR-RFLP using the hypervariable region of HMTp210 are alternative methods to identify the serovar of A. paragallinarum. (+info)Haemophilus paragallinarum is a gram-negative, rod-shaped bacterium that is the primary cause of infectious coryza, an upper respiratory disease in birds, particularly chickens. The bacteria colonize and infect the mucosal surfaces of the upper respiratory tract, leading to clinical signs such as sneezing, coughing, nasal discharge, and difficulty breathing. In severe cases, it can result in significant economic losses for poultry farmers due to decreased egg production, poor feed conversion, and increased mortality rates. It is transmitted through direct contact with infected birds or contaminated surfaces, making biosecurity measures essential to control its spread.
Haemophilus is a genus of Gram-negative, facultatively anaerobic bacteria that are commonly found as part of the normal microbiota of the human respiratory tract. However, some species can cause infections in humans, particularly in individuals with weakened immune systems or underlying medical conditions.
The most well-known species is Haemophilus influenzae, which was originally identified as a cause of influenza (hence the name), but it is now known that not all strains of H. influenzae cause this disease. In fact, the majority of H. influenzae infections are caused by strains that produce a polysaccharide capsule, which makes them more virulent and able to evade the host's immune system.
Haemophilus influenzae type b (Hib) was once a major cause of serious bacterial infections in children, including meningitis, pneumonia, and epiglottitis. However, since the introduction of vaccines against Hib in the 1980s, the incidence of these infections has decreased dramatically.
Other Haemophilus species that can cause human infections include Haemophilus parainfluenzae, Haemophilus ducreyi (which causes chancroid), and Haemophilus aphrophilus (which can cause endocarditis).
Pasteurellaceae is a family of Gram-negative, facultatively anaerobic or aerobic, non-spore forming bacteria that are commonly found as normal flora in the upper respiratory tract, gastrointestinal tract, and genitourinary tract of animals and humans. Some members of this family can cause a variety of diseases in animals and humans, including pneumonia, meningitis, septicemia, and localized infections such as abscesses and cellulitis.
Some notable genera within Pasteurellaceae include:
* Pasteurella: includes several species that can cause respiratory tract infections, septicemia, and soft tissue infections in animals and humans. The most common species is Pasteurella multocida, which is a major pathogen in animals and can also cause human infections associated with animal bites or scratches.
* Haemophilus: includes several species that are normal flora of the human respiratory tract and can cause respiratory tract infections, including bronchitis, pneumonia, and meningitis. The most well-known species is Haemophilus influenzae, which can cause severe invasive diseases such as meningitis and sepsis, particularly in young children.
* Mannheimia: includes several species that are normal flora of the upper respiratory tract of ruminants (such as cattle and sheep) and can cause pneumonia and other respiratory tract infections in these animals. The most common species is Mannheimia haemolytica, which is a major pathogen in cattle and can also cause human infections associated with animal contact.
* Actinobacillus: includes several species that are normal flora of the upper respiratory tract and gastrointestinal tract of animals and can cause respiratory tract infections, septicemia, and localized infections in these animals. The most common species is Actinobacillus pleuropneumoniae, which causes a severe form of pneumonia in pigs.
Overall, Pasteurellaceae family members are important pathogens in both veterinary and human medicine, and their infections can range from mild to severe and life-threatening.
Haemophilus influenzae is a gram-negative, coccobacillary bacterium that can cause a variety of infectious diseases in humans. It is part of the normal respiratory flora but can become pathogenic under certain circumstances. The bacteria are named after their initial discovery in 1892 by Richard Pfeiffer during an influenza pandemic, although they are not the causative agent of influenza.
There are six main serotypes (a-f) based on the polysaccharide capsule surrounding the bacterium, with type b (Hib) being the most virulent and invasive. Hib can cause severe invasive diseases such as meningitis, pneumonia, epiglottitis, and sepsis, particularly in children under 5 years of age. The introduction of the Hib conjugate vaccine has significantly reduced the incidence of these invasive diseases.
Non-typeable Haemophilus influenzae (NTHi) strains lack a capsule and are responsible for non-invasive respiratory tract infections, such as otitis media, sinusitis, and exacerbations of chronic obstructive pulmonary disease (COPD). NTHi can also cause invasive diseases but at lower frequency compared to Hib.
Proper diagnosis and antibiotic susceptibility testing are crucial for effective treatment, as Haemophilus influenzae strains may display resistance to certain antibiotics.
Haemophilus infections are caused by bacteria named Haemophilus influenzae. Despite its name, this bacterium does not cause the flu, which is caused by a virus. There are several different strains of Haemophilus influenzae, and some are more likely to cause severe illness than others.
Haemophilus infections can affect people of any age, but they are most common in children under 5 years old. The bacteria can cause a range of infections, from mild ear infections to serious conditions such as meningitis (inflammation of the membranes surrounding the brain and spinal cord) and pneumonia (infection of the lungs).
The bacterium is spread through respiratory droplets when an infected person coughs or sneezes. It can also be spread by touching contaminated surfaces and then touching the mouth, nose, or eyes.
Prevention measures include good hygiene practices such as handwashing, covering the mouth and nose when coughing or sneezing, and avoiding close contact with people who are sick. Vaccination is also available to protect against Haemophilus influenzae type b (Hib) infections, which are the most severe and common form of Haemophilus infection.
Haemophilus ducreyi is a gram-negative, oxidase-negative, facultatively anaerobic coccobacillus that is the causative agent of chancroid, a sexually transmitted genital ulcer disease. It requires factors X and V for growth, which makes it fastidious and difficult to culture. The organism primarily infects the epithelial cells of the skin and mucous membranes, causing painful, necrotic ulcers with ragged borders and suppurative inguinal lymphadenopathy. Chancroid is a significant co-factor in the transmission of HIV. Infections caused by H. ducreyi are more common in tropical and developing regions, where it remains an important public health concern.
"Pasteurella" is a genus of Gram-negative, facultatively anaerobic coccobacilli that are part of the family Pasteurellaceae. These bacteria are commonly found as normal flora in the upper respiratory tracts of animals, including cats, dogs, and livestock. They can cause a variety of infections in humans, such as wound infections, pneumonia, and septicemia, often following animal bites or scratches. Two notable species are Pasteurella multocida and Pasteurella canis. Proper identification and antibiotic susceptibility testing are essential for appropriate treatment.
'Bird diseases' is a broad term that refers to the various medical conditions and infections that can affect avian species. These diseases can be caused by bacteria, viruses, fungi, parasites, or toxic substances and can affect pet birds, wild birds, and poultry. Some common bird diseases include:
1. Avian influenza (bird flu) - a viral infection that can cause respiratory symptoms, decreased appetite, and sudden death in birds.
2. Psittacosis (parrot fever) - a bacterial infection that can cause respiratory symptoms, fever, and lethargy in birds and humans who come into contact with them.
3. Aspergillosis - a fungal infection that can cause respiratory symptoms and weight loss in birds.
4. Candidiasis (thrush) - a fungal infection that can affect the mouth, crop, and other parts of the digestive system in birds.
5. Newcastle disease - a viral infection that can cause respiratory symptoms, neurological signs, and decreased egg production in birds.
6. Salmonellosis - a bacterial infection that can cause diarrhea, lethargy, and decreased appetite in birds and humans who come into contact with them.
7. Trichomoniasis - a parasitic infection that can affect the mouth, crop, and digestive system in birds.
8. Chlamydiosis (psittacosis) - a bacterial infection that can cause respiratory symptoms, lethargy, and decreased appetite in birds and humans who come into contact with them.
9. Coccidiosis - a parasitic infection that can affect the digestive system in birds.
10. Mycobacteriosis (avian tuberculosis) - a bacterial infection that can cause chronic weight loss, respiratory symptoms, and skin lesions in birds.
It is important to note that some bird diseases can be transmitted to humans and other animals, so it is essential to practice good hygiene when handling birds or their droppings. If you suspect your bird may be sick, it is best to consult with a veterinarian who specializes in avian medicine.
Haemophilus vaccines are vaccines that are designed to protect against Haemophilus influenzae type b (Hib), a bacterium that can cause serious infections such as meningitis, pneumonia, and epiglottitis. There are two main types of Hib vaccines:
1. Polysaccharide vaccine: This type of vaccine is made from the sugar coating (polysaccharide) of the bacterial cells. It is not effective in children under 2 years of age because their immune systems are not yet mature enough to respond effectively to this type of vaccine.
2. Conjugate vaccine: This type of vaccine combines the polysaccharide with a protein carrier, which helps to stimulate a stronger and more sustained immune response. It is effective in infants as young as 6 weeks old.
Hib vaccines are usually given as part of routine childhood immunizations starting at 2 months of age. They are administered through an injection into the muscle. The vaccine is safe and effective, with few side effects. Vaccination against Hib has led to a significant reduction in the incidence of Hib infections worldwide.