The in-vitro activity of sitafloxacin against the most common bacterial pathogens isolated from the clinical samples

BACKGROUND

Sitafloxacin exhibited a broad antibacterial spectrum and excellent antimicrobial activity against common bacterial pathogens causing different infections. Sitafloxacin has also exhibited excellent clinical efficacy in patients who had failed to respond to other antibacterial therapy. However, sitafloxacin has not been available in Vietnam yet, so that the local information of the in-vitro spectrum of this antibiotic to the most common bacterial pathogens isolated from Vietnam

AIMS

Using the microdilution method to determine ratio of sensitivity and the MIC₉₀ of Sitafloxacin and other common used antibiotics against the most common bacterial pathogens isolated from the clinical samples collected from patients with acute lower respiratory tract infections and with acute urinary tract infections

MATERIALS – METHODS

The objectives of the study are the bacterial pathogens isolated from sputum including S. pneumoniae, H. influenzae, M. catarrhalis, S. aureus, K. pneumoniae, P. aeruginosa, and A. baumannii; and from the urine including E. coli, P. mirabilis, E. faecalis, E. faecium, A. baumannii, P. aeruginosa, and K. pneumoniae. For each pathogen, at least 30 isolates are collected. The isolates are collected from different hospitals in Ho Chi Minh City and in Ha Noi for one year (2015). The determination of the MIC of the antibiotics against the bacterial pathogens were carried out by the broth microdilution method following CLSI 2015. To carry-out the MIC, the plates with 96 wells containing the dry antibiotics with serial concentration custom fabricated and supplied by Eiken Chemical Co., Ltd. (Dry Plate Eiken, Tokyo, Japan) were used.

RESULTS - DISCUSSIONS

From 1/2015 to 12/2015, 682 isolates were collected from 4 hospitals in Ho Chi Minh and 1 hospital in Ha Noi including 457 isolates from lower respiratory tract infection and 225 isolates from urinary tract. The in-vitro activity of sitafloxacin to the most common Gram [-] rod were demonstrated in the tables 1 and 2 bellows:

Against the most common community bacterial pathogens the received results demonstrated that 100% of H. influenzae were sensitive to sitafloxacin, equivalent to amoxicillin/clavulanic acid, cefotaxime, ceftriaxone, and imipenem, however sitafloxacin gave the very low MIC₉₀, only 0.12µg/ml, the lowest versus other antibiotics. Against S. pneumoniae, 100% of the isolates were sensitive to sitafloxacin and the MIC₉₀ was 0.06µg/ml, the lowest versus other antibiotics. Sitafloxacin was among the antibiotics with very high sensitivity ratio to M. catarrhalis (96.2%) and gave the lowest MIC₉₀

CONCLUSION

This is the first trial to find-out the in-vitro activity of Sitafloxacin against the different bacterial pathogens isolated from clinical samples in Viet Nam. The results collected from the study demonstrated that Sitafloxacin exhibited excellent in-vitro antibacterial activity against both Gram-positive and Gram-negative bacteria that are mostly encountered in the clinical fields of infections. This result can confirm that Sitafloxacin can be considered as one of the most powerful antibiotics that doctor can use to treat various infections caused by antibiotic resistant bacterial pathogens.