Molecular identification of TEM-1 beta-lactamase in a Pasteurella multocida isolate of human origin.

Two clinical strains of Pasteurella multocida were isolated from an HIV-infected patient who developed arthritis. Strain FB-1, which was isolated from a dog-bite wound, was resistant to narrow-spectrum penicillins. The second strain, FB-2, which was present in blood cultures as well as the dog-bite wound, was susceptible to all beta-lactam agents. Arbitrarily primedpolymerase chain reaction and pulsed-field gel electrophoresis revealed that these two isolates were genetically indistinguishable. 16S rDNA gene sequencing facilitated identification at the subspecies level. Amoxicillin resistance determinant was located on a highly unstable 4.3-kb plasmid, pFAB-1. Isoelectrofocusing and polymerase chain reaction amplification followed by sequencing revealed the presence of a pI 5.4 TEM-1 beta-lactamase. This description is the first of a TEM-1 Beta-lactamase' in a Pasteurella multocida strain of human origin.