الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Microbial contamination of pharmaceuticals has been an everlasting problem for researchers as well as pharmaceutical manufacturers worldwide. This contamination can result in the spoilage of pharmaceutical formulas, serious health threats to consumers, as well as product recall and thus economic losses for the manufacturing company. Despite the implementation of proper measures for the preservation and packaging of pharmaceutical products, in addition to a well-established GMP compliance, the main concern of researchers and manufacturers nowadays is to develop rapid, accurate and advanced methods for the microbiological quality testing of pharmaceuticals. Earlier detection of microbial contamination allows rapid implementation of proper corrective actions resulting in optimization of risk assessment.
In this investigation, the aim was to identify various bacterial contaminants, isolated from different pharmaceuticals, using biochemical methods (conventional tests and API kits) as well as molecular methods (PCR assays and DNA sequencing). We then compared between both methods with respect to time and cost required for the recovery and identification of pharmaceutical bacterial contaminants, in addition to their minimum detection limit (MDL).
Among the 85 tested pharmaceuticals (pharmaceutical preparations, cosmetic preparations, herbal products and raw materials), a total of 41 bacterial contaminants were successfully isolated from 31 preparations. These bacterial contaminants were identified as follows: 13 Gram-positive cocci (12 coagulase-negative staphylococci (CNS) and 1 Kocuria varians), 1 Gram-positive rod (Microbacterium paraoxydans), 16 Bacillus spp., in addition to 11 Gram-negative rods (10 enterobacteria and 1 Pseudomonas stutzeri).
Conventional biochemical methods helped us to conclusively identify 3 (out of 12) CNS to the species level (16A, 20B and 57A as S. epidermidis), and these results were corroborated using the API Staph kit. Moreover, the API Staph kit enabled the successful identification of 2 more CNS (isolate 36 as S. warneri and isolate 23 as S. haemolyticus). However, both biochemical methods showed inconclusive or contradictory identification results for the remaining 7 CNS. On that score, PCR-based methods and 16S rRNA sequencing proved to be superior in the identification of these 7 CNS to the species level (isolates 20A and 52, S. epidermidis; isolates 17, 22, 44 and 62, S. warneri; and isolate 16B, S. saprophyticus).
Identification of the Kocuria isolate (24A) to the species level was achieved by biochemical methods, without the need to resort to a PCR-based assay. On the other hand, the Microbacterium isolate (24B) was identified with the help of PCR, followed by sequencing of the conserved 16S rRNA gene, since no biochemical methods were available for its identification.
Concerning the 16 Bacillus isolates, and due to the great physiological versatility within the genus Bacillus, biochemical identification was not useful for their identification. Nonetheless, a PCR-based method using primer pairs specific to the 3 most common and/or pathogenic Bacillus spp., was relatively useful for the identification of 13 (81.2%) of them.