Haemophilus

Haemophilus
	Haemophilus influenzae on a Chocolate agar plate.
Scientific classification
Kingdom:	Bacteria
Phylum:	Proteobacteria
Class:	Gammaproteobacteria
Order:	Pasteurellales
Family:	Pasteurellaceae
Genus:	Haemophilus; Winslow et al. 1917
Species
	H. aegyptius; H. ducreyi; H. felis; H. haemoglobinophilus[1]; H. haemolyticus; H. influenzae; H. parainfluenzae; H. paracuniculus; H. parahaemolyticus; H. paraphrohaemolyticus[1]; H. pittmaniae; H. piscium[1]; H. segnis; H. sputorum[1];

Haemophilus is a genus of Gram-negative, pleomorphic, coccobacilli bacteria belonging to the family Pasteurellaceae.[2][3] While Haemophilus bacteria are typically small coccobacilli, they are categorized as pleomorphic bacteria because of the wide range of shapes they occasionally assume. These organisms inhabit the mucous membranes of the upper respiratory tract, mouth, vagina, and intestinal tract.[4] The genus includes commensal organisms along with some significant pathogenic species such as H. influenzae—a cause of sepsis and bacterial meningitis in young children—and H. ducreyi, the causative agent of chancroid. All members are either aerobic or facultatively anaerobic. This genus has been found to be part of the salivary microbiome.[5]

Metabolism

Members of the genus Haemophilus will not grow on blood agar plates, as all species require at least one of these blood factors for growth: hemin (X-factor) and/or nicotinamide adenine dinucleotide (V-factor). They are unable to synthesize important parts of the cytochrome system needed for respiration, and they obtain these substances from the heme fraction, known as the X factor, of blood hemoglobin. The culture medium must also supply the cofactor nicotinamide adenine dinucleotide (from either NAD+ or NADP+), which is known as the V factor. Clinical laboratories use tests for the requirement of the X and V factors to identify the isolates as Haemophilus species.[4]

Chocolate agar is an excellent Haemophilus growth medium, as it allows for increased accessibility to these factors.[6] Alternatively, Haemophilus is sometimes cultured using the "Staph streak" technique: both Staphylococcus and Haemophilus organisms are cultured together on a single blood agar plate. In this case, Haemophilus colonies will frequently grow in small "satellite" colonies around the larger Staphylococcus colonies because the metabolism of Staphylococcus produces the necessary blood factor byproducts required for Haemophilus growth.

Strain[7]	Needs X-Factor	Needs V-Factor	Hemolysis on HB/Rabbit blood
H. aegyptius	+	+	–
H. ducreyi	+	–	–
H. influenzae	+	+	–
H. haemolyticus	+	+	+
H. parainfluenzae	–	+	–
H. parahaemolyticus	–	+	+

gollark: Connect it to `bash` and implement BF virii.

gollark: There is ongoing work to encrypt that, too, to make TLS connections basically utterly opaque to firewalls.

gollark: Yeß. Also, there's a bit of TLS-level negotiation stuff.

gollark: HTTP extensions don't care whether they're going over HTTPS or not, mostly.

gollark: In any case my webserver doesn't support it yet.

References

LPSN lpsn.dsmz.de
Holt JG, ed. (1994). Bergey's Manual of Determinative Bacteriology (9th ed.). Williams & Wilkins. ISBN 0-683-00603-7.
Kuhnert P; Christensen H, eds. (2008). Pasteurellaceae: Biology, Genomics and Molecular Aspects. Caister Academic Press. ISBN 978-1-904455-34-9. .
Tortora, Gerard J; Funke, Berdell R; Case, Christine L (2016). Microbiology: An Introduction (12th ed.). Boston: Pearson. p. 301. ISBN 978-0321929150. OCLC 892055958.
Wang, Kun; Lu, Wenxin; Tu, Qichao; Ge, Yichen; He, Jinzhi; Zhou, Yu; Gou, Yaping; Nostrand, Joy D Van; Qin, Yujia; Li, Jiyao; Zhou, Jizhong; Li, Yan; Xiao, Liying; Zhou, Xuedong (10 March 2016). "Preliminary analysis of salivary microbiome and their potential roles in oral lichen planus". Scientific Reports. 6 (1): 22943. doi:10.1038/srep22943. PMC 4785528. PMID 26961389.
Ryan KJ; Ray CG, eds. (2004). Sherris Medical Microbiology (4th ed.). McGraw Hill. ISBN 0-8385-8529-9.
McPherson RA; Pincus MR, eds. (2011). Henry's Clinical Diagnosis and Management by Laboratory Methods (22nd ed.). Elsevier. ISBN 978-1437709742.

External links

Haemophilus chapter in Baron's Medical Microbiology (online at the NCBI bookshelf).
Raw Living Radio Interviews Dr Robert Cassar as part of a 3 Show Series in HD 2014 from the EarthShiftProject.com, an educational and informational research organization

This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.

[Haemophilus-1] LPSN lpsn.dsmz.de

[Bergeys-2] Holt JG, ed. (1994). Bergey's Manual of Determinative Bacteriology (9th ed.). Williams & Wilkins. ISBN 0-683-00603-7.

[KuhnertChristensen-3] Kuhnert P; Christensen H, eds. (2008). Pasteurellaceae: Biology, Genomics and Molecular Aspects. Caister Academic Press. ISBN 978-1-904455-34-9. .

[microbiology-4] Tortora, Gerard J; Funke, Berdell R; Case, Christine L (2016). Microbiology: An Introduction (12th ed.). Boston: Pearson. p. 301. ISBN 978-0321929150. OCLC 892055958.

[5] Wang, Kun; Lu, Wenxin; Tu, Qichao; Ge, Yichen; He, Jinzhi; Zhou, Yu; Gou, Yaping; Nostrand, Joy D Van; Qin, Yujia; Li, Jiyao; Zhou, Jizhong; Li, Yan; Xiao, Liying; Zhou, Xuedong (10 March 2016). "Preliminary analysis of salivary microbiome and their potential roles in oral lichen planus". Scientific Reports. 6 (1): 22943. doi:10.1038/srep22943. PMC 4785528. PMID 26961389.

[Sherris-6] Ryan KJ; Ray CG, eds. (2004). Sherris Medical Microbiology (4th ed.). McGraw Hill. ISBN 0-8385-8529-9.

[Henry's-7] McPherson RA; Pincus MR, eds. (2011). Henry's Clinical Diagnosis and Management by Laboratory Methods (22nd ed.). Elsevier. ISBN 978-1437709742.