Detection of methicillin-resistant Staphylococcus aureus directly by loop-mediated isothermal amplification and direct cefoxitin disk diffusion tests

We evaluated the utility of 2 methods for detection of methicillin-resistant Staphylococcus aureus [MRSA] directly from signal-positive blood culture bottles: loop-mediated isothermal amplification [LAMP] assay, and direct cefoxitin disk diffusion [DCDD] test using a 30 microg cefoxitin disk. In parallel, standard microbiological identification and oxacillin susceptibility testing with MecA PCR was performed. Of 60 blood cultures positive for Gram-positive cocci in clusters, LAMP [via detection of the FemA and MecA genes] showed 100% sensitivity and specificity for identification of MRSA/MSSA. When coagulase-negative staphylococci were tested, sensitivity for detection of methicillin resistance was 91.7% and specificity was 100%. DCDD along with direct tube coagulase assay detected only 80.6% of MRSA/MSSA. LAMP showed higher diagnostic accuracy although DCDD was more cost-effective and did not require additional reagents or supplies

High prevalence of Klebsiella pneumoniae carbapenemase-mediated resistance in K. pneumoniae isolates from Egypt

The emergence and rapid spread of antibiotic-resistant Klebsiella pneumoniae isolates harbouring the bla[KPC] gene that encodes for carbapenemase production have complicated the management of patient infections. This study in a tertiary care hospital in Egypt used real-time PCR assay to test ertapenem-nonsusceptible isolates of K. pneumoniae for the presence of the bla[KPC] gene and compared the results with modified Hodge test. Antibiotic sensitivity was performed by standard methods, and interpreted following both the old CLSI breakpoints [M100-S19] for carbapenems and the revised breakpoints [M100-S22]. From the 45 non-duplicate isolates of K. pneumoniae recovered from different clinical specimens, a high prevalence of ertapenem-nonsusceptible isolates [44.4%] was reported using the new lower CLSI breakpoints. The bla[KPC] gene was confirmed in 14/20 [70.0%] of these isolates. The high prevalence of ertapenem nonsusceptibility at a tertiary care hospital in Egypt was predominantly attributed to K. pneumoniae carbapenemase-mediated resistance mechanisms in K. pneumoniae isolates

Toxicokinetic study of a sea anemone toxin in mice after intraperitoneal injection

One of the two low molecular weight [200-300 Dalton] toxins extracted from sea anemone, Gyrostoma helianthus, from the vicinity of Hurgada, Red Sea, Egypt was subjected to a toxicokinetic study. The concentration-time profile of the acetylcholine esterase [AchE] inhibitor sea anemone toxin was characterized using 20g male mice injected with 10 mg toxin as a single dose. Serum and five tissues were collected at 8 interval points [5, 10, 20, 30, 45, 60, 75 and 90 minutes]. The toxin was extracted from these biological matrixes by acetonitrile. The Gyrostoma helianthus toxin showed short action as the half-life values vary from 4.5 to 27.5 min .The maximum time [tmax] was 30 min in serum and in all tissues except the heart which peaked at 45 min. The sea anemone toxin also showed first order kinetic

Self-evaluation of clinical-skill among dental hygiene students in King Saud University

The aim of this study was to determine whether the senior dental hygienestudents in Riyadh are able to assess accurately their own clinical skills. Thirty-five senior dental hygiene students evaluated their skills in relationto the skills of their classmates. The perceived scores were compared withactual clinical evaluations by Dental Hygiene Faculty. Results indicate thatthe chi-square homogeneity test produced different levels of significance inthe four skills. Two statistically significant values were found charting andscaling skills. P-values were 0.037, 0.59, 0.01 and 0.35 [respectively asarranged above]. The evaluation of the overall outcome of all four skills wasperformed and suggested that the null hypothesis can be rejected and thatthere are significant differences between actual and perceived skill rankingsfor the particular group of students included in this study