title: Genospecies and virulence factors of Aeromonas species in different sources in a North African country.
abstract: Aeromonads of medical importance have been reported from numerous clinical, food, and water sources, but identification of genospecies and virulence factors of Aeromonas species from countries in North Africa and the Middle East are few.
  
  
  
  In total 99 Aeromonas species isolates from different sources (diarrheal children [n=23], non-diarrheal children [n=16], untreated drinking water from wells [n=32], and chicken carcasses [n=28]) in Tripoli, Libya, were included in the present investigation. Genus identification was confirmed by biochemical analysis, and genospecies were determined using a combination of 16S rDNA variable region and gyrB sequence analysis. Polymerase chain reaction (PCR) was used to detect genes encoding toxins from 52 of the isolates.
  
  
  
  We identified 44 isolates (44%) as A. hydrophila (3 [3.0%] subspecies anaerogenes, 23 [23%] subspecies dhakensis, and 18 [18%] subspecies ranae); 27 isolates (27%) as A. veronii; 23 isolates (23%) as A. caviae; and 5 isolates (5.0%) as other genospecies. The genes encoding aerolysin (aer), cytolytic enterotoxin (act), and A. hydrophila isolate SSU enterotoxin (ast) were detected in 45 (87%), 4 (7.7%), and 9 (17%) of the 52 isolates tested, respectively. The gene encoding an extracellular lipase (alt) was not detected.
  
  
  
  The majority of aeromonads from Libya fall within three genospecies (i.e. A. hydrophila, A. veronii, and A. caviae), and genes coding for toxin production are common among them.
authors.affiliation: El-Nakheel Compound, Cairo, Egypt; ghenghesh_micro@yahoo.com.
authors.forename: Khalifa Sifaw
authors.initials: KS
authors.lastname: Ghenghesh
authors.affiliation: United States Naval Medical Research Unit-3, Cairo, Egypt.
authors.forename: Salwa F
authors.initials: SF
authors.lastname: Ahmed
authors.affiliation: Department of Biomedical Sciences, Sassari University, Sassari, Italy.
authors.forename: Piero
authors.initials: P
authors.lastname: Cappuccinelli
authors.affiliation: United States Naval Medical Research Unit-3, Cairo, Egypt.
authors.forename: John D
authors.initials: JD
authors.lastname: Klena
mesh_terms: D000333:Aeromonas / Q000302:isolation & purification* / Q000472:pathogenicity; D002648:Child; D002675:Child, Preschool; D004275:DNA, Ribosomal; D003967:Diarrhea / Q000453:epidemiology / Q000382:microbiology*; D005243:Feces / Q000382:microbiology*; D006801:Humans; D007223:Infant; D008002:Libya / Q000453:epidemiology; D008460:Meat / Q000382:microbiology*; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D037521:Virulence Factors; D014871:Water Microbiology
chemical_list: D004275:DNA, Ribosomal; D037521:Virulence Factors
keywords: Aeromonas; Libya; genospecies; virulence factors