Mycoplasmas are widely distributed in nature. Various species of these small prokaryotic organisms cause economically important infections in domestic animals (like mammals and birds), and infect also reptiles, as well as man.
The haemoplasmas are haemotropic mycoplasmas, bacteria that parasitize red blood cells and can induce haemolytic anaemia. They are currently classified within the genus Mycoplasma in the Mycoplasmataceae family of bacteria.
Obligate intracellular Gram negative coccoid organisms of the Anaplasma, Ehrlichia and Rickettsia genera are vector-borne members of the Rickettsiales order infecting humans and a wide variety of domestic and wild animals worldwide (Allison and Little, 2013).
This beta-haemolytic Lancefield group G gram-positive bacterium is considered part of the commensal mucosal flora of the oral cavity, upper respiratory tract, genital organs and perianal region in cats. The infection seems to be sporadic in single-cat households, especially in older cats (Greene and Prescott, 2012).
Pasteurella multocida, a gram-negative, facultative anaerobic, non-spore-forming pleomorphic coccobacillus, is a commensal bacterium and part of the natural flora in the nasopharynx and upper respiratory tract of the cat (Freshwater, 2008;
Coxiella burnetii is a Gram-negative, obligate intracellular, small, pleomorphic bacterium belonging to the order Legionellales. This organism has a complicated life cycle with different morphological stadia. It may occur as a small-cell variant and a large-cell variant.
Leptospires are mobile, thin, filamentous bacteria of a size of 6.0-25.0 mm length and 0.1-0.2 mm width, that appear as fine spirals often with hook-shaped ends (Fig. 1) (Bharti et al., 2003; Adler and de la Pena Moctezuma, 2010).
The plague is currently endemic in many parts of the world and foci of plague occur in Asia, Africa and the Americas in semiarid areas where flea vectors are active all year round and rodent reservoirs are abundant (Valles et al., 2020).
Currently most of human cases occur in
This bacterial species was discovered in ground squirrels in Tulare County, California, in 1911. Tularaemia is a potentially fatal zoonosis mostly found in the Northern hemisphere.
Capnocytophaga canimorsus and C. cynodegmi are part of the normal bacterial flora in the oral cavity of dogs and cats; C. canimorsus is more pathogenic and causes more severe infections in humans.
Mycobacteria are intracellular, acid-fast, slow-growing bacilliform Gram-positive aerobic bacteria, highly resistant to environmental conditions (Greene and Gunn-Moore, 2006; Gunn-Moore, 2010). Mycobacterial taxonomy is complex, and many species can infect cats and cause different clinical presentations.
The pathogenic role of many Bartonella spp. as pathogens of humans and domestic animals is still unknown. Bartonella henselae is the causative agent of cat scratch disease (CSD) in humans, a self-limiting regional lymphadenopathy and cats are its main reservoir host.
Chlamydia felis is a Gram-negative bacterium that is an obligate intracellular parasite of cats. Chlamydia felis does not survive outside of the host so close contact between cats is required for transmission, usually via ocular discharges. Chlamydiosis typically affects young cats under 9 months of age.
Bordetella bronchiseptica (Bb) is a primary respiratory pathogen of cats, particularly in high population density conditions such as rescue shelters and multicat households.
Bordetella (B.) pertussis, B. parapertussis and Bb are closely-related Gram-negative coccobacilli that colonise the respiratory tracts of mammals. B.