Chlamydiales, rickettsiales, mycoplasma

• Chlamydiales are the smallest bacteria in size, followed by Rickettsiales, Coxiella, and Mycoplasma.
• Chlamydiales, Coxiella, and Mycoplasma are spread long distance by air, while Anaplasma, Ehrlichia, Rickettsia, and Coxiella are spread by arthropods.
• Intracellular Pathogens II: Rickettsiales
• Biology of Ticks Volume 2
• Anaplasma marginale and Anaplasma phagocytophilum: Rickettsiales pathogens of veterinary and public health significance
• Dr. Reta D. Abdi
• Genetic diversity of Anaplasma species major surface proteins and implications for anaplasmosis serodiagnosis and vaccine development
• All four groups of bacteria are intra-cellular pathogens of animals and arthropods.
• All four groups of bacteria infect diverse vertebrate species, with Rickettsiales also infecting arthropods.
• All four groups of bacteria are obligate intracellular bacteria, with Mycoplasma living both in intracellular and extracellular environments.
• The reasons for seeking intracellular lifestyle in animal cells include ATP shortage, essential amino acids, cholesterol demand, and protection from the host cell cytoplasm, which is highly permeable.
• Anaplasma bovis in monocyte Mycoplasma colonies need a living cell culture to grow them.
• Mycoplasma colonies grow on bacteriological culture media, but are highly fastidious and slow growing, causing chronic disease.
• Rickettsiales have a tough transmission cycle between diverse arthropods, domestic animals, and wild vertebrate animals.
• Several tick genera and species can transmit Anaplasma, Ehrlichia, and Rickettsia in nature.
• Diagnosis of Anaplasma, Ehrlichia, and Rickettsia can be done through isolation and identification methods in animals as well as ticks.
• Serology includes IFA, ELISA, and IH.
• The most effective therapy for all three kinds of typhus is the antibiotic doxycycline.
• Offspring from an infected arthropod are not free from Rickettsia.
• Control and prevention of Anaplasma, Ehrlichia, and Rickettsia involves using Tetracycline, Doxycycline, and Chloramphenicol.
• Rickettsia is a long-term carrier that persists in nature.
• Treatment of Anaplasma, Ehrlichia, and Rickettsia cases includes chloramphenicol, Tetracycline, and Doxycycline, with Doxycycline being the most effective drug.
• PCR is a quick, convenient method for detection of Anaplasma, Ehrlichia, and Rickettsia.
• Reservoir vertebrate hosts for Rickettsiales are widely distributed, serving as a source of infection.
• Chlamydiales are transmitted mainly by airborne & contagious transmission using its spore-like particle (elementary body).
• Ehrlichia causes lysis of RBC, WBC and endothelium.
• Coxiella causes endothelial cell lysis and phagocytes.
• Anaplasma causes lysis of RBC, platelets and WBC.
• Rickettsia causes endothelial cell lysis/bleeding (rash).
• Chlamydia, Coxiella & Mycoplasma have tropism to similar cells (mucosal epithelium); hence; infect similar body sites: mucus membranes & cause similar mucosal diseases.
• Chlamydia is a gram-negative cocci bacteria, however, its cell wall has a tiny or no peptidoglycan, so it is best stained by Giemsa stain than Gram stain and is best treated by tetracycline and chloramphenicol than beta-lactams.
• Mycoplasma are transmitted mainly by airborne & contagious transmission using its spore-like particle (elementary body).
• Rickettsiales are transmitted by arthropod vectors such as ticks, and their predilection sites are red blood cells (RBC), white blood cells (WBC) or blood vessels.
• Both Chlamydiales and Coxiella produce two life forms: a spore-like particle during an extracellular life, which is the infective form, and actively replicative cells during intracellular life, which is the host cell destructive form.
• Ehrlichia is a problem of white blood cells in ruminants and canines.
• Rab7 protein is involved in the mechanisms of spread to the adjacent cells from infected blood/endothelial cells.
• Ruminant Ehrlichiosis is a disease of ruminants caused by Ehrlichia spp.
• ECH0825 inhibits ROS production in mitochondria.
• Anaplasma is a problem of red blood cells in ruminants except two Anaplasma spp.
• Phospholipase A2 helps to lyse infected cells.