The schema brings easy and highly discriminatory detection of subtype or outbreakspecific markers from whole genome sequencing data to your fingertips. Citrobacter species are differentiated by their ability to convert tryptophan to indole, ferment lactose, and use malonate. Citrobacter species are responsible for sporadic and epidemic clusters of neonatal sepsis and meningitis, and c. Two chromosomally located qnrb variants, qnrb6 and the new qnrb16, in citrobacter spp. The comparison of biochemical characteristics of the eight strains with those of some citrobacter species in bergeys manual was shown in table 1. Characterization of the chromosomal class a lactamase. The rank order by region for confirmed esblproducing enterobacter spp. Citrobacter species are enteric gramnegative bacilli. Antimicrobial resistance and cytotoxicity of citrobacter spp.
Citrobacter koseri formerly c itrobacter diversus is a motile gramnegative bacillus usually arising from urinary and gastrointestinal tracts. Subcategory citrobacter species a a braakii freundii gillenii murliniae rodenticum sedlakii werkmanii youngae b amalonaticus farmeri c koseridiversus b acollectively identified as the citrobacter freundii complex. Many citrobacter infections are nosocomially acquired. Ribosomal rnabased phylogeny is capable of distinguishing three groups of citrobacter species, of which, group i encompasses at least eight species and includes c. Citrobacter freundii is a frequent cause of nosocomial infections and a known cause of diarrheal infections, and has increasingly. Biochemical identification ofcitrobacter species defined by dna hybridization and description of citrobacter gillenii sp. The bacteria have a long rod shape with a typical length of 15. This genus was proposed in 1932 by werkman and gillen 61. Apr 22, 2011 the citrobacter species, including citrobacter freundii, are aerobic gramnegative bacilli.
In many countries including japan, the status of emerging antimicrobial resistance among serratia spp. This organism has been reported as a cellulolytic bacterium, which is biotechnologically important because it can be used as a gene donor for the ethanol and biofuel industries. Using a selection of 4 annotated, publicly available reference genomes capturing the known diversity within the citrobacter. Citrobacter youngae and pantoea agglomerans peritonitis in. Pdf biochemical identification ofcitrobacter species. It has been described as causing human disease, but is generally found as a nonpathogenic organism in human stools. These non koseri and non freundii citrobacter species can cause intraabdominal infections in immunosuppressed individuals 4. One hundred thirtysix strains were identified to species level by dna relatedness and then identified phenotypically in a blinded fashion. Draft genome sequence of citrobacter gillenii mbtc3. Citrobacter freundii is a member of the family enterobacteriaceae and is often the cause of significant opportunistic infections. Cko was found to display only 41% identity with sed. In this study, we aimed to determine the genetic diversity and relationships of citrobacter spp. Citrobacter freundii wikispecies, free species directory. They ferment glucose and other carbohydrates with the production of acid and gas.
Most cases reported have occurred in immunocompromised hosts. Prevalence of citrobacter in various clinical specimens samples total no. Citrobacter as a uropathogen, its prevalence and antibiotics. Smear made from a liquid culture tryptic soy broth. Citrobacter koseri is known to be an uncommon but serious cause of both sporadic and epidemic septicemia and meningitis in neonates and young infants. Production of cellulose and curli fimbriae by members of the. Utis caused by citrobacter species have been described in 5 to 12% of bacterial urine isolates in adults. They are rarely the source of illnesses, except for infections of the urinary tract and infant meningitis and sepsis. Biochemicalcharacteristics of the representative citrobacter strains. No transcriptional regulator was found upstream from bla cko. Formerlycitrobacter genomospecies 10 and citrobacter murliniae sp. The mortality and morbidity rate ofcitrobacter meningitis is unacceptably high. These facultative anaerobes typically are motile by means of peritrichous flagella.
Antimicrobial resistance and cytotoxicity of citrobacter. Citrobacter koseri is another classic bacterium described in neonatal neurologic infections, in particular as a cause of devastating neonatal meningitis characterized by the formation of multiple brain abscesses. Common infections are of the urinary tract, line infections, pneumonia, and in neonates cns infections. The present study assessed the prevalence and antibiotic sensitivity pattern of citrobacter. Biochemical characteristics of strain 425c1 were identical to those described for c. The gene bla cko encoding the chromosomal class a lactamase of citrobacter koseri was cloned and sequenced. In this study, we aimed to determine the genetic diversity, the antimicrobial resistance profiles and in vitro virulence properties of c. Fatal citrobacter farmeri meningitis in a patient with. Citrobacter freundii are long rodshaped bacteria typically 15. In order to determine the genetic diversity, in vitro virulence properties and antimicrobial resistance profiles of citrobacter spp. Differentiation and susceptibility of citrobacter isolates. However, little information is available about cp citrobacter spp very few studies have reported c. View enhanced pdf access article on wiley online library html view download pdf for offline viewing.
Ability of commercial identification systems to identify newly recognized species of citrobacter. The genus can be divided in 43 oserogroups, based on the o antigen of the lipopolysaccharide lps and in 20 chemogroup, based on the sugar composition of the lps. Multilocus sequence analysis based on housekeeping genes fusa, leus, pyrg, rpob and recn, showed that the two strains formed a distinct phylogenetic lineage within the genus citrobacter. They ferment mannitol with production of gaseous h 2 s, and they can also use citrate as sole carbon source. Citrobacter koseri an overview sciencedirect topics. Between 2015 and 2016, the bacteraemia rate for enterobacter spp. Citrobacter species are differentiated by their ability to convert tryptophan to indole c. Two csf specimens both grew oxidasenegative and gramnegative bacilli. Characterization of antimicrobial resistance in serratia spp. Murray pr, baron ej, pfaller ma, tenover fc, yolken rh,editors.
The genus citrobacter includes a wide variety of human and animal pathogens. Epidemiology, prevalence and identification of citrobacter. Citrobacter is a genus of gramnegative coliform bacteria in the family enterobacteriaceae the species c. These isolates were also looked at for the presence of insertion elements is 26 and orf5, which play an important role in the resistance gene pool. Significance of primary intraabdominal infection chiangching shih, yeechun chen, shanchwen chang, kwentay luh, and weichuan hsieh from the section ofinfectious disease, department of internal medicine and the department oflaboratory medicine, national taiwan university hospital, taipei, taiwan. Citrobacter is a genus of gramnegative coliform bacteria in the enterobacteriaceae family. Medical microbiology department, royal liverpool hospital, duncan building, daulby street, liverpool l69 3ga, uk. Citrobacter species are commonly found in water, soil, food, and the intestinal tracts of animals and humans. We report on a 30yearold man, with no medical past, hospitalized for infective aortic endocarditis due to c. Citrobacter is a genus of gramnegative coliform bacteria in the enterobacteriaceae family the species c. Strains 9779t and a121, recovered respectively from human faeces and well water, were compared to currently known species of the genus citrobacter using genotypic and phenotypic approaches.
Dna relatedness and phenotypic tests were used to determine how well these species can be identified. Citrobacter species, belonging to the family enterobacteriaceae, are environmental organisms commonly found in soil, water, and the intestinal tracts of animals and humans. Members of the genus citrobacter are gramnegative, nonsporeforming rods belonging to the family enterobacteriaceae and, as the name suggests, usually utilize citrate as a sole carbon source. Citrobacter sedlakii is a species of gramnegative bacteria. Approximately 80% of infants with meningitis due to citrobacter spp. Sir, urinary tract infection uti continues to be the commonest nosocomial infection according for approximately 40% of all hospital acquired infections and it is one of the most important causes of morbidity and mortality. Infective endocarditis due to citrobacter koseri in an. Gramnegative coliform bacteria in the enterobacteriaceae family. Citrobacter is a genus of gramnegative coliform bacteria in the family enterobacteriaceae. Two chromosomally located qnrb variants, qnrb6 and the new. Urine samples which yielded the growth citrobacter spp. They are rarely the source of illnesses, except for infections of the urinary tract and infant meningitis and sepsis organism. Genetic diversity, multidrug resistance, and virulence of citrobacter.
Biochemical identification ofcitrobacter species defined. No early features distinguish meningitis due to citrobacter spp. Citrobacter definition of citrobacter by medical dictionary. Citrobacter species are differentiated by their ability to convert tryptophan to. Citrobacter portucalensis is a bacterium in the genus citrobacter which has been isolated from a water well sample in portugal.
In a, 16s rrna pcr was performed using genomic dna from isolates that gave amplicons in pcr reactions using primers designed to amplify either of the citrobacter spp. Urinary tract infection utis caused by citrobacter species have been described in 5 to 12% of bacterial urine isolates in. The fatality rate associated with neonatal meningitis is 25 to 50%. Frontiers genetic diversity, multidrug resistance, and. Genetic characterization of atypical citrobacter freundii. Anthony hart medical microbiology department, royal liverpool hospital, duncan building, daulby street, liverpool l69 3ga, uk. Citrobacter was initially classified as genomospecies 5 of the 11 genomospecies in the c.
Table current species within the genus citrobacter. Silent and missense mutations were detected in four bla cko. Citrobacter freundii is a species of facultative anaerobic gramnegative bacteria of the family enterobacteriaceae. Before 1993, only three species, citrobacter freundii, citrobacter koseri citrobacter diversus, and citrobacter amalonaticus, were recognized. It is an important economic species in inland china due to its largescale processing and. Lipinski t, zatonsky gv, kocharova na, jaquinod m, forest e, shashkov as, et al. The eight isolates were gramnegative, motive, short rods. Citrobacter freundii is a frequent cause of nosocomial infections and a known cause of diarrheal infections, and has increasingly become multidrug resistant mdr.
A collection of 40 confirmed isolates of citrobacter spp. In terms of decarboxylation of lysine, which is the differential biochemical test between salmonella spp. This might be because of a lack of preventive measures during the handling of the patients in our institution. Urinary tract infection utis caused by citrobacter species have been described in 5 to 12% of bacterial urine. Characterization of antimicrobial resistance in serratia. Neonatal bacterial meningitis remains a disease with unacceptable rates of morbidity and mortality despite the availability of effective antimicrobial therapy. Recent work describing six named species and two unnamed genomospecies within citrobacter has enlarged the genus to 11 species. Plesiomonas, serratia, and other members of the enterobacteriaceae.
Citrobacter isolates were found to be third most common organism causing uti in hospitalized patients after escherichia coli and klebsiella species accounting to 9. They are mostly a nosocomial pathogen found in compromised hosts, patients over 60 years of age, and in neonates. Klebsiella, citrobacter, enterobacter and serratia spp. Citrobacter youngae and pantoea agglomerans peritonitis in a. Neonatal disease can occur as earlyonset or lateonset presentations. Citrobacter koseri, formerly known as citrobacter diversus, is a facultative anaerobe and motile, gramnegative bacillus of the family enterobacteriaceae. Species of the citrobacter, enterobacter, and serratia genera hereafter abbreviated as ces are. Citrobacter freundii fitness during bloodstream infection. Citrobacter freundii invades and replicates in human brain. Structures of two ochain polysaccharides of citrobacter gillenii o9a,9b lipopolysaccharide. Citrobacter species are straight, facultative anaerobic, gramnegative bacilli and are typically motile by means of peritrichous flagellae.
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