الفهرس 
REVIEW OF LITERATUREOnly 14 pages are availabe for public view
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Abstract
A
ccurate identification of the Streptococci to the species level is important to determine the pathogenic potential of individual species and monitor trends in antimicrobial susceptibility and emerging infections.
Virulent species such as Streptococcus pyogenes and Streptococcus pneumoniae are associated with diverse syndromes of superficial infection, invasive infection and exotoxin production. Less virulent species such as Viridans streptococci are common harmless human commensals but are frequently cultured from clinical samples.
Many species of Streptococci, including Strep pyogenes (group A), Strep agalactiae (group B), and the Enterococci (group D), are characterized by combinations of features that include: colony growth characteristics, hemolysis patterns on blood agar (hemolysis [α or β] or no hemolysis), antigenic composition of group-specific cell wall substances, and biochemical reactions. Strep pneumoniae types are further classified by the antigenic composition of the capsular polysaccharides.
Phenotypic identification of Streptococci remains routinely problematic in clinical diagnostic laboratories and most of the isolates remain identified only to the genus level. Accurate identification of the Streptococci clinical isolates is important for treatment purposes.
The present study was conducted during the period between August 2021 and February 2022 in Ain shams university hospitals. A total of 50 Streptococcal isolates were recovered from different clinical specimens submitted to the main Microbiology Laboratory, Ain Shams University Hospitals for routine culture and antimicrobial susceptibility testing.
Isolates of Streptococcus spp. Were presumptively identified phenotypically following the microbiology laboratory procedures (Gram stain and catalase) and were subjected to further subspecies identification by API20 Strep and Vitek 2 ID cards.
In a comparison of the Vitek2 and the API20 strep identification results, there was 90% agreement (45/50 isolates) for all isolates tested. It was noticed that Vitek2 failed to identify 2 isolates and 3 isolates were mismatched between the two methods. This shows highly statistically significant agreement between ¬API vs. Vitek2.
CONCLUSION
S
treptococci are important primary pathogen. Timely identification, proper clinical correlation and appropriate therapeutic intervention can lead to favorable outcome.
Identification by the Vitek2 and the API20 Strep showed 90% agreement with kappa value 0.9.
Automated systems such as API20 strep and Vitek2 are of a limited utility for identification of Mitis Streptococci.
RECOMMENDATIONS
A
lthough Parallel comparison between Vitek2 and API20 strep micro system showed excellent agreement, we recommend the use of Vitek2 in identification of Streptococci as it is faster, less costy and objective.
We also recommend that further studies to be done with large number of isolates especially on VGS strains.