Pathogenic analysis and drug resistance of pathogenic bacteria causing infectious keratitis

Abstract

Objective To analyze the pathogen distribution and drug sensitivity test results of the corneal ulcers patients who diagnosed as infectious keatitis. Methods The corneal ulcers of the 91 patients with infectious keratitis treated in the department of ophthalmology in the hospital from February 2014 to October 2015 were collected and the specimen was sent for the fungal and bacteria culture and drug sensitivity test of the pathogens. The culture result of corneal ulcers of the patients with infectious keratitis and the drug susceptibility testing result were summarized. Results Among the 91 patients with infectious keratitis, the fungal keratitis were 57 cases accounted for 62.2%; the bacterial keratitis 33 cases accounted for 36.3%; acanthamoeba keratitis 1 case accounted for 1.1%. Among the 57 patients with fungal keratitis, Fusarium species were 27 cases accounted for 47.4%, Alternaria species 21 cases accounted for 36.8%, No-spore species 6 cases accounted for10.5%. Among the 33 patients with bacterial keratitis, gram positive cocci and gram negative bacilli were the commonest pathogens accounted for 72.7% and 21.2%, respectively. Streptococcus pneumoniae was the main pathogen among the gram positive cocci accounted for42.4%. The results of bacteria drug sensitivity tests showed the Streptococcus had the high susceptibility to Cephalosporins, levofloxacin and ofloxacin which was more than 70%. The susceptibility to vancomycin was 100%. The results of fungal drug sensitivity tests showed the terbinafine had 100% susceptibility to the five fungi, Fusarium had the higher susceptibility to the Fluconazole and ketone which was more than 70%. The lower susceptibility was to the amphotericin and voriconazole which was less than 50%. Alternaria species had the higher susceptibility to the four antifungal drugs (terbinafine ketone amphotericin and voriconazole) which was more than 80%, the lower susceptibility to Fluconazole which was 38.1%. No-spore species had the 100% susceptibility to the four antifungal drugs except for voriconazole. Conclusions Fusarium species is the first pathogen of infectious keatitis, Fusarium is the main pathogen and always take the top spot in fungal keratitis. Streptococcus pneumoniae from gram positive cocci is the major pathogen in bacterial keratitis. The Cephalosporins, levofloxacin and ofloxacin can be the conventional drugs because they have the higher susceptibility to the bacterial keratitis caused by Streptococcus. Terbinafine can be the empirical antifungal drugs. Key words: Fungal keratitis; Bacteria keratitis; Drug resistance; Acanthamoeba keratitis