Background: Bacillus species are widely distributed in all environments including health care settings and represent one of the highly resistant organisms. Objective: This study aimed to find out the prevalence, molecular characterization of genetic diversity among studied Bacillus species in Egyptian hospitals environment and their antibiotic susceptibility profile. Methods: A total 528 swab samples were collected from different hospitals environment. Isolation and identification were performed according to conventional bacteriological methods, semi-automated and molecular characterization methods. Antimicrobial susceptibility was carried against different groups of antimicrobial agents. Results: The most isolated microorganism was Bacillus spp. (43.2%), followed by coagulase-negative Staphylococci (19.2%), Staphylococcus aureus (15.2%), Enterococus spp. (10.1%), Gram-negative rods (8.9%), and Micrococcus spp.(3.4 %). The most prevalent species, were Bacillus cereus (46.6%) followed by Bacillus subtilus (38.1%) while, Bacillus pumilus was the least (1.1%). A majority of Bacillus isolates (25.6%) were isolated in Internal medicine department followed by Emergency department (18.8%) while operating rooms showed the lowest prevalence rate (4.5%). Antimicrobial susceptibility testing revealed high resistance of Bacillus isolates to βlactams and tetracycline antibiotics. Multi-drug resistance (MDR) isolates which resistance to three or more antibiotics was (21.6%). Susceptibility reports of the 176 Bacillus isolates revealed 45 antibitypes and the most common was antibiotype 31, which included 32 isolates (18.2%), that is resistant to both penicillin and cefoxitin. Conclusions: This study revealed that, dissemination of Bacillus species in study hospital environments with high resistance to β-lactams and tetracycline antibiotics. The molecular analysis revealed the existence of genetic diversity among studied Bacillus isolates. Thus, monitoring the hospital environment is an important tool in the prevention of hospital-associated infection by Bacillus species.

Universally Primed-PCR (UP-PCR) and Internal Transcribed Spacer-PCR (ITS-PCR) based genomic fingerprinting techniques are considered a good methods that rely on specifically targeted primers. These techniques, which analyse the rDNA, have been shown to be relatively robust and discriminatory. This study was designed to investigate and characterize the molecular variation among Cladosporium strains collected at different sites in Cairo by using two different fingerprinting methods, Universally Primed-PCR (UP-PCR) and Internal Transcribed Spacer (UP-PCR) technique. The Cladosporium isolates investigated were isolated from air of Cairo by settle plate method. The samples were then purified and identified by using culture based techniques, microscopical methods, and biochemical reactions followed by confirmation in the regional center for mycology and biotechnology (RCMB). Molecular fingerprinting, and genetic similarities among Cladosporium species populations depending on microsatellites-polymerase chain reaction (ITS-PCR). Primers used are ITS4, and ITS5. PCR products were digested with 3 restriction enzymes and separated by agarose electrophoresis. Restriction patterns generated by CfoI, MspI and RsaI. In addition, we have applied the Universally Primed PCR (UP-PCR) technique using two primers L21 and Fok1.The current work showed prominent discriminatory power given by amplification of internal transcribes spacers PCR regions followed by restriction with CfoI enzyme than other endonucleases. moreover, Fok1 primer revealed minor variability among Cladosporium strains using UP-PCR genotyping technique.