ABSTRACT
Objective To investigate the antimicrobial resistance of Haemophilus influenzae in Peking Union Medical College Hospital for rational clinical treatment.Methods A total of 223 strains of H .influenzae were collected from patients from Jan-uary 2008 to December 2011.The antimicrobial susceptibility was tested by Kirby-Bauer method.Production of beta-lactamase was detected using nitrocefin disks.WHONET 5.6 software was used to analyze the data of susceptibility testing.Results Tri-methoprim-sulfamethoxazole and tetracycline were the two antimicrobial agents to which the H .influenzae strains were most resistant.Theβ-lactamase positive ampicillin resistant strains accounted for 15.9 %,andβ-lactamase negative ampicillin resist-ant strains accounted for 8.9%.Conclusions H .influenzae is mainly isolated from respiratory specimens.Majority of the anti-microbial agents still show good antibacterial activity against H .influenzae strains.However,H .influenzae isolates are highly resistant to trimethoprim-sulfamethoxazole and tetracycline.
ABSTRACT
One hundred and seventy-two ampicillin-resistant E. coli strains isolated from commercial chickens in Enugu State, Nigeria, were screened for beta-lactamase production using the broth method with nitrocefin® as the chromogenic cephalosporin to detect enzyme production. Beta-lactamase producing strains were further examined for extended-spectrum beta-lactamase (ESBL) production using the Oxoid combination discs method. One hundred and seventy (98.8 percent) of the 172 ampicillin-resistant E. coli strains produced beta-lactamase enzyme. Sixteen (9.4 percent) beta-lactamase producers were phenotypically confirmed to produce ESBLs. Six of the ESBL producing strains were only detected with ceftazidime versus ceftazidime/clavulanate combination while ten of the ESBL producers were detected with cefotaxime versus cefotaxime/clavulanate combination. Chicken may serve as a reservoir of ESBL-producing E. coli strains which could be transferred to man and other animals.
Cento e setenta e duas cepas de Escherichia coli resistentes a ampicilina isoladas de frangos em Enugu State, Nigéria, foram avaliadas quanto à produção de beta-lactamase através do uso de método em caldo com nitrocefin® como indicador cromogênico da produção da enzima. Em seguida, as cepas produtoras de beta-lactamase foram examinadas quanto à produção de beta-lactamase de espectro expandido (ESBL) através do método de discos combinados Oxoid. Entre as cepas de Escherichia coli resistentes a ampicilina, cento e setenta (98,8 por cento) produziram beta-lactamase. Testes fenotípicos indicaram que dezesseis (9,4 por cento) das cepas produtoras de beta-lactamase produziram ESBL. Seis cepas produtoras de ESBL foram detectadas apenas com a combinação ceftazidima versus cefotaxime/clavulanato, enquanto dez cepas produtoras de ESBL foram detectadas com a combinação cefotaxime versus cefotaxime/clavulanato. Frangos podem ser reservatório de cepas de E.coli produtoras de ESBL, que podem ser transferidos para o homem e outros animais.