Microbiological studies on bacterial isolates from penicillins filling cleanroom

Abstract

Aseptic processing is a critical method for the preparation of thermolabile sterile parenteral drug products. Sterile β-lactam antibiotics are extremely deactivated by heat, so the method of choice for their processing is through aseptic filling. The consequences of contamination on aseptically-filled products are harmful to the patient and having financial risk to the manufacturer. The aim of this work is isolation of bacterial contaminants from Classes A and B of aseptic penicillins filling area in Pharco Pharmaceuticals Egypt, studying the ability of these contaminants to produce penicillinase and studying the sensitivity of these contaminants to biocides. In addition, possible interaction between the commonly used biocides was checked. Thirty-one bacterial isolates were collected from cleanroom class A and seventy isolates from class B. Isolates were identified using macroscopic, microscopic examination, and the identity was confirmed by biochemical methods. Staphylococcus sp. were the predominant microorganism isolated, which include S. epidermidis (50%) and S. aureus (5%), followed by Micrococcus sp. (27%) then Corynebacterium sp. (10%). Bacillus sp. and P. aeroginosa were in the same proportion (4%). Isolates showed a heterogeneous susceptibility toward β-lactams when applying Kirby-Bauer disk diffusion technique. Accordingly, isolates were introduced into the aseptic area through different sources. Fifty-two isolates were found to be penicillinase producers. The effectiveness of biocides was tested according to modified suspension method and surface contact method. Isolates had different sensitivity toward the tested biocides. Based on the suspension method, at five minutes contact time, 1% Minncare was effective against 23 isolates out of 27 tested. While 1% Kleencare DS607 was effective against 21 isolates out of 27 tested and 70% isopropyl alcohol was effective against 23 isolates out of 27 tested. Two hard surfaces were selected for surface contact test, aluminum foil and powder free sterile surgical gloves. Results were similar to a great extent when biocides were applied to either aluminum surface or rubber surface, except an intangible difference in few cases. The concomitant use of at least two biocides within the cleanroom is necessary. Interactions between the selected biocides were also examined using macrodilution checkerboard method. No interaction between hydrogen peroxide and DS 607 was observed. The effectiveness of isopropyl alcohol was enhanced when DS607 present as 6.25 ppm in isopropyl alcohol. The activity of hydrogen peroxide and isopropyl alcohol was reduced when mixed to each other.