Moraxella catarrhalis бактериясы: сипаттамасы мен аурулары

Species of bacterium

Moraxella catarrhalis is a fastidious, nonmotile, Gram negative, aerobic, oxidase positive diplococcus that can cause infections of the respiratory system, middle ear, eye, central nervous system, and joints of humans. It causes the infection of the host cell by sticking to the host cell using trimeric autotransporter adhesins.

Moraxella catarrhalis is a human pathogen with an affinity for the human upper respiratory tract. Other primates, such as macaques, might become infected by this bacterium.

Moraxella catarrhalis was previously placed in a separate genus named Branhamella. The rationale for this was that other members of the genus Moraxella are rod shaped and rarely caused infections in humans. However, results from DNA hybridization studies and 16S rRNA sequence comparisons were used to justify inclusion of the species M. catarrhalis in the genus Moraxella. As a consequence, the name Moraxella catarrhalis is currently preferred for these bacteria. Nevertheless, some in the medical field continue to call these bacteria Branhamella catarrhalis. Moraxella is named after Victor Morax, a Swiss ophthalmologist who first described this genus of bacteria. Catarrhalis is derived from catarrh, from the Greek meaning "to flow down" (cata implies down; rrh implies flow), describing the profuse discharge from eyes and nose typically associated with severe inflammation in colds.

The whole genome sequence of M. catarrhalis CCUG 353 type strain was deposited and published in DNA Data Bank of Japan, European Nucleotide Archive, and GenBank in 2016 under the accession number LWAH00000000.

This bacterium has been known to cause otitis media, bronchitis, sinusitis, and laryngitis. Elderly patients and long term heavy smokers with chronic obstructive pulmonary disease should be aware that M. catarrhalis is associated with bronchopneumonia, as well as exacerbations of existing chronic obstructive pulmonary disease. The peak rate of colonization by M. catarrhalis appears to occur around 2 years of age, with a striking difference in colonization rates between children and adults (very high to very low). Moraxella catarrhalis has recently been gaining attention as an emerging human pathogen. It has been identified as an important cause in bronchopulmonary infection, causing infection through pulmonary aspiration in the upper pulmonary tract. Additionally, it causes bacterial pneumonia, especially in adults with a compromised immune system. It has also been known to cause infective exacerbations in adults with chronic lung disease, and it is an important cause in acute sinusitis, maxillary sinusitis, bacteremia, meningitis, conjunctivitis, acute purulent irritation of chronic bronchitis, urethritis, sepsis (although this is rare), septic arthritis (which is also a rare occurrence),and acute laryngitis in adults and acute otitis media in children. M. catarrhalis is an opportunistic pulmonary invader, and causes harm especially in patients who have compromised immune systems or any underlying chronic disease. Bacteremia infections caused by M. catarrhalis have a 21% mortality rate among patients. However, this may have been due to a lack of knowledge about the bacterium because of its recent recognition as a pathogen. for this genotypically diverse organism, as well as determining factors involved with virulence, e. g. complement resistance. Lipooligosaccharide is considered one possible virulence factor. The beta lactamases are produced in the cytoplasm and translocated to the periplasmic space by twin arginine translocation pathway, which is a protein secretion pathway that transports proteins across a bilipid membrane in a folded state. M. catarrhalis produces and secretes beta lactamase containing outer membrane vesicles that can function as an extracellular delivery system of beta lactam resistance that promotes the survival of otherwise beta lactam sensitive bacteria in the vicinity of M. catarrhalis. This behavior is beneficial for the other bacteria and can make the antibiotic treatment of polymicrobial infections more difficult. Also, the resistance of M. catarrhalis to other antibiotics may be attributed to beta lactamase, as well, because the use of these antibiotics has triggered an increase in development of beta lactamase, which resists antibiotics. The recognition of M. catarrhalis as a pathogen has led to studies for possible antibodies against it, which have led to a wider understanding of its composition. The outer membrane protein (OMP) profiles of different strains of M. catarrhalis are extremely similar to each other. The M. catarrhalis TAT translocase protein encoding genes tatA, tatB and tatC are located in a single tatABC locus in the bacterial chromosome and are likely to be transcriptionally and translationally linked due to a single nucleotide overlap between each gene. Multiple M. catarrhalis proteins have been predicted or tested to contain the highly conserved leader motif for translocation and to be transported by the TAT pathway. Beta lactamases BRO 1 and BRO 2 have been shown to be transported by the TAT pathway. Other potential passenger proteins include an iron dependent peroxidase like protein, a cytochrome c like protein and a phosphate ABC transporter inner membrane protein like protein. A functioning TAT pathway is necessary for the optimal growth of M. catarrhalis even in conditions without antibiotics.