''Christensenella hongkongensis'' is a species of clinically relevant
gram-positive
In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall.
Gram-positive bact ...
coccobacilli, first isolated from patients in Hong Kong and Canada in 2006.
Although the species remains relatively rare, it has a high mortality rate of up to 50%.
''Christensenella'' is thought to be broadly distributed globally, as it has been isolated from patient blood cultures around the world including Hong Kong, South Korea, New Zealand, Canada, Sweden, France and Italy. Fewer than 15 cases of ''C. hongkongensis'' have been observed worldwide.
Phenotypic characteristics
''C. hongkongensis'' grow on sheep blood agar as nonhemolytic pinpoint colonies after 48 h of incubation at 37 °C in an anaerobic environment. All are
catalase positive and motile, with
flagella. They produce acid from arabinose, glucose and xylose. They do not produce
indole
Indole is an aromatic heterocyclic organic compound
In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other c ...
or reduce
nitrate.
Clinical features and diagnosis
Symptoms of ''C. hongkongensis'' infection include fever, vomiting, abdominal distension and constipation. The bacteria have been present in cases of bacteraemia.
To accurately identify ''C. hongkongensis'', 16S rRNA sequencing is recommended.
Other identification methods such as
MALDI-TOF
In mass spectrometry, matrix-assisted laser desorption/ionization (MALDI) is an ionization technique that uses a laser energy absorbing matrix to create ions from large molecules with minimal fragmentation. It has been applied to the analysis of ...
, have not been able to identify the bacteria correctly.
Treatment
Antibiotic treatment is usually administered upon ''C. hongkongensis'' infection. ''C. hongkongensis'' has been shown to be susceptible to antibiotics including kanamycin,
vancomycin
Vancomycin is a glycopeptide antibiotic medication used to treat a number of bacterial infections. It is recommended intravenously as a treatment for complicated skin infections, bloodstream infections, endocarditis, bone and joint infections, ...
,
cefuroxime
Cefuroxime, sold under the brand name Zinacef among others, is a second-generation cephalosporin antibiotic used to treat and prevent a number of bacterial infections. These include pneumonia, meningitis, otitis media, sepsis, urinary tract inf ...
,
ciprofloxacin
Ciprofloxacin is a fluoroquinolone antibiotic used to treat a number of bacterial infections. This includes bone and joint infections, intra abdominal infections, certain types of infectious diarrhea, respiratory tract infections, skin inf ...
and
metronidazole
Metronidazole, sold under the brand name Flagyl among others, is an antibiotic and antiprotozoal medication. It is used either alone or with other antibiotics to treat pelvic inflammatory disease, endocarditis, and bacterial vaginosis. It i ...
.
In one case, the patient recovered without any antibiotic treatment.
References
Gram-positive bacteria
Species described in 2006
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