''Glaesserella parasuis'' (formerly known as ''Haemophilus parasuis'') is a

Gram-negative Gram-negative bacteria are bacteria that, unlike gram-positive bacteria, do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. Their defining characteristic is that their cell envelope consists ...

bacterium belonging to the family

Pasteurellaceae The Pasteurellaceae comprise a large family of Gram-negative bacteria. Most members live as commensals on mucosal surfaces of birds and mammals, especially in the upper respiratory tract. Pasteurellaceae are typically rod-shaped, and are a notabl ...

. It is best known as the causative agent of Glässer's disease in

pigs The pig (''Sus domesticus''), also called swine (: swine) or hog, is an omnivorous, domesticated, even-toed, hoofed mammal. It is named the domestic pig when distinguishing it from other members of the genus '' Sus''. Some authorities cons ...

History and taxonomy

Originally described as ''Haemophilus parasuis'' by Biberstein and White in 1969, it was reclassified into the newly created genus ''Glaesserella'' in 2020 based on comprehensive

phylogenomic Phylogenomics is the intersection of the fields of evolution and genomics. The term has been used in multiple ways to refer to analysis that involves genome data and evolutionary reconstructions. It is a group of techniques within the larger fields ...

analyses.

Morphology

''Glaesserella parasuis'' is a

coccobacillus Bacterial cellular morphologies are the shapes that are characteristic of various types of bacteria and often key to their identification. Their direct examination under a light microscope enables the classification of these bacteria (and archae ...

. Cells typically appear as short rods or coccobacilli, often forming pairs or short chains. It is non-motile and non-spore-forming.

Growth conditions

The bacterium requires enriched media containing NAD (V factor) and exhibits optimal growth under aerobic conditions at 37 °C. Colonies typically appear small, smooth, and translucent on

chocolate agar Chocolate agar (CHOC) or chocolate blood agar (CBA) is a nonselective, Growth medium#Enriched media, enriched growth medium used for isolation of pathogenic bacteria. It is a variant of the blood agar plate, containing red blood cells that have ...

blood agar An agar plate is a Petri dish that contains a growth medium solidified with agar, used to Microbiological culture, culture microorganisms. Sometimes selective compounds are added to influence growth, such as antibiotics. Individual microorganism ...

supplemented with NAD.

Clinical significance

''Glaesserella parasuis'' is the causative agent of Glässer's disease, an infectious condition characterized by

polyserositis Familial Mediterranean fever (FMF) is a hereditary inflammatory disorder. FMF is an autoinflammatory disease caused by mutations in the Mediterranean fever (MEFV) gene, which encodes a 781–amino acid protein called pyrin. While all ethnic ...

(inflammation of serosal surfaces),

arthritis Arthritis is a general medical term used to describe a disorder that affects joints. Symptoms generally include joint pain and stiffness. Other symptoms may include redness, warmth, Joint effusion, swelling, and decreased range of motion of ...

meningitis Meningitis is acute or chronic inflammation of the protective membranes covering the brain and spinal cord, collectively called the meninges. The most common symptoms are fever, intense headache, vomiting and neck stiffness and occasion ...

, and

pneumonia Pneumonia is an Inflammation, inflammatory condition of the lung primarily affecting the small air sacs known as Pulmonary alveolus, alveoli. Symptoms typically include some combination of Cough#Classification, productive or dry cough, ches ...

, primarily affecting young piglets.

Epidemiology

The bacterium commonly colonizes the

upper respiratory tract The respiratory tract is the subdivision of the respiratory system involved with the process of conducting air to the alveoli for the purposes of gas exchange in mammals. The respiratory tract is lined with respiratory epithelium as respiratory ...

of pigs, and outbreaks of disease typically occur when piglets are under stress or have compromised

immunity Immunity may refer to: Medicine * Immunity (medical), resistance of an organism to infection or disease * ''Immunity'' (journal), a scientific journal published by Cell Press Biology * Immune system Engineering * Radiofrequence immunity ...

, such as during

weaning Weaning is the process of gradually introducing an infant human or other mammal to what will be its adult diet while withdrawing the supply of its mother's milk. In the United Kingdom, UK, weaning primarily refers to the introduction of solid ...

Clinical signs

Affected animals may exhibit

fever Fever or pyrexia in humans is a symptom of an anti-infection defense mechanism that appears with Human body temperature, body temperature exceeding the normal range caused by an increase in the body's temperature Human body temperature#Fever, s ...

respiratory distress Shortness of breath (SOB), known as dyspnea (in AmE) or dyspnoea (in BrE), is an uncomfortable feeling of not being able to breathe well enough. The American Thoracic Society defines it as "a subjective experience of breathing discomfort that c ...

lameness A limp is a type of asymmetric abnormality of the gait. Limping may be caused by pain, weakness, neuromuscular imbalance, or a skeletal deformity. The most common underlying cause of a painful limp is physical trauma; however, in the absence ...

joint swelling A joint effusion is the presence of increased intra-articular fluid. It may affect any joint. Commonly it involves the knee (see knee effusion). Diagnostic approach The approach to diagnosis depends on the joint involved. While aspiration o ...

, and

neurological Neurology (from , "string, nerve" and the suffix -logia, "study of") is the branch of medicine dealing with the diagnosis and treatment of all categories of conditions and disease involving the nervous system, which comprises the brain, the s ...

symptoms. Mortality rates can be significant without appropriate treatment or preventive measures.

Diagnosis

Diagnosis involves clinical observations,

necropsy An autopsy (also referred to as post-mortem examination, obduction, necropsy, or autopsia cadaverum) is a surgical procedure that consists of a thorough examination of a corpse by dissection to determine the cause, mode, and manner of death ...

findings (such as fibrinous polyserositis), and laboratory confirmation through bacterial isolation and molecular techniques such as PCR.

Treatment and prevention

Treatment typically involves

antibiotics An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting pathogenic bacteria, bacterial infections, and antibiotic medications are widely used in the therapy ...

. Preventive measures include

vaccination Vaccination is the administration of a vaccine to help the immune system develop immunity from a disease. Vaccines contain a microorganism or virus in a weakened, live or killed state, or proteins or toxins from the organism. In stimulating ...

, good

biosecurity Biosecurity refers to measures aimed at preventing the introduction or spread of harmful organisms (e.g. viruses, bacteria, plants, animals etc.) intentionally or unintentionally outside their native range or within new environments. In agricult ...

practices, and stress minimization, particularly during weaning.

References

External links

NCBI Taxonomy Browser: Glaesserella parasuis

BacDive – The Bacterial Diversity Metadatabase
{{Taxonbar, from=Q110111511 Pasteurellales Gram-negative bacteria Bacteria described in 1969