Background Cholera is a disease of significant public concern in the Democratic Republic of the Congo. Cholera is typically diagnosed using culture and biochemistry. However, the genes responsible for cholera's toxigenicity can only be identified using molecular techniques that are not readily available. Here, we applied two polymerase chain reaction (PCR) methods to detect the ctxA and tcP genes and determined the antibiotic sensitivity of V. cholerae isolated in DR Congo.
ResultsFindings from agglutination tests demonstrated that all 31 samples belonged to the biotype El Tor, serogroup O1. Antibiotic susceptibility tests showed an acceptable susceptibility to Doxycycline (70.9%), an excellent susceptibility to Ciprofloxacin (93.4%) and Gentamicin (100%), and 100% resistance to Sulfamethoxazole-Trimethoprim (Bactrim). Real-time PCR identified the gene ctxA in 100% of pure culture samples and 72.2% of polymicrobial samples. Duplex-PCR simultaneously identified ctxA and tcP in 100% and 18.8% of all pure and polymicrobial samples, respectively.
ConclusionThe molecular tests applied in this study detected the genes responsible for the pathogenicity in V. cholerae in all pure culture and polymicrobial samples with variable sensitivity. The trait of increased anti-microbial resistance (AMR) highlights the need for regular monitoring of the genetic composition of V. cholerae.
Keywords: cholera, ctxA (Cholera toxin unit A), tcP (toxin coregulated pilus), Polymerase Chain Reaction, antibiotics susceptibility, Democratic Republic of the Congo.