Detection of methicillin resistant staphylococcus aureus with reduced susceptibility to vancomycin

Background: As there is no molecular-based assays available for the detection of hVISA and VISA. However, increasing amounts of data support a number of methods for the screening and confirmation of heterogeneous vancomycin intermediate S. aureus [hVISA] and vancomycin intermediate S. aureus [VISA] infection. The vancomycin MIC result alone is unable to accurately distinguish hVISA from VSSA isolates, and the use of MIC testing alone will fail to detect h VISA strains that are relatively common among isolates of Staphylococcus aureus [S. aureus] with broth MICs of 2g per ml. of Staphlococcus aureus [S. aureus] with broth MICs of 2 g per ml

Objective: The aim of the present work was to detect the efficacy of phenotypic and automated methods for detection of MRSA with reduced susceptibility to vancomycin. It aimed also, to determine the best MIC concentration in vancomycin screening agar for detection of VISA among MRSA isolates

Methods: one hundred MRSA isolated were obtained from 100 patients from different departments of Ain Shams University Hospitals during the period from October 2015 to the end of April 2016. They were isolated from different clinical specimens; sputum, wound swabs, blood, pus, urine, and body fluid that were referred to central microbiology laboratory for routine culture and sensitivity. Detection of S. aureus with reduced susceptibility to vancomycin was done by vancomycin screening agar with different concentrations 2,4,6 ug/ml with and without casein, MIC broth microdilution method for vancomycin according to CLSI

Results: Out of 100 MRSA isolates, vancomycin screening agar 2 ug/ml with casein showed highest detection rate for VISA isolates [48%] among other screening agars. Vancomycin screening agar 6 ug/ml without casein gave the lowest detection rate [29%]. So, adding casein to vancomycin screening agar did not increase detection of VISA in any of vancomycin screening agar except for that with 2 ug/ml vancomycin. Vancomycin screening agar 2 ug/ml with casein gave the best sensitivity among all vancomycin screening agar tested. VITEK 2 system failed to detect any isolates with reduced susceptivility to vancomycin. They were sensitive to linezolid [100%] followed by tigecyclin [99%] then Quinupristin-dalfopristin [91%]. However, most of the isolates were resistant to tetracycline [85%] followed by gentamicin [80%] then ciprofloxacin [63%]

Conclusion: BHI agar with 2 ug/ml vancomycin and 16 g/l casein is a reliable, easy to perform, and inexpensive method to screen large number of S. aureus isolates for detection of reduced susceptibility to vancomycin on a daily basis. Applying quadruplicate technique in vancomycin screening agar may increase the yield for detection of VISA isolates. Although vancomycin screening agar 6 ug/ml is recommended by CLSI as a screening method for detection of VISA, yet it did not perform well and underestimated VISA isolates. VITEK 2 system is not an appropriate method for detection of S. aureus with reduced susceptibility to vancomycin [VISA]. MRSA isolates with reduced susceptibility to vancomycin can be treated effectively with Linezolid

Role of aqueous humor matrix metalloproteinase-2 and its inhibitor and connective tissue growth factor in the pathogenesis of primary open angle glaucoma and pseudoexfolliative glaucoma

To study the presence and possible quantitative differences of matrix metalloproteinase-2 [MMP2] and its endogenous inhibitor, tissue inhibitor metalloproteinase-2 [TIMP2] and connective tissue growth factor [CTGF] in aqueous humor of patients with pseudoexfoliative glaucoma [PEXG], primary open angle glaucoma [POAG] and cataract patients [serving as controls] and to determine the potential role of these elements in the pathogenesis of glaucomas. Aqueous humor samples were collected from 75 patients [25 patients with PEXG, 25 with POAG and 25 with senile cataract, who served as controls]. Glaucoma and cataract subjects underwent routine glaucoma trabeculectomy and cataract extraction surgeries respectively. MMP2, TIMP2 and CTGF levels were measured using specific enzyme immunoassay [ELISA]. Total MMP2 was detected in significantly higher concentration in aqueous samples from PEXG eyes and POAG eyes compared to control eyes. The ratio of MMP2 to its principle inhibitor TIMP2 was balanced in cataract samples as well as in samples from PEXG glaucoma patients but increased in POAG samples. The CTGF concentration in PEXG group was significantly higher compared to POAG and cataract groups. Complex changes in MMP2- TIMP2 balance in aqueous humor may promote the abnormal matrix accumulation [in PEXG] and matrix degeneration [in POAG] which may be causally involved in the pathogenesis of both glucomas. The increased CTGF concentration supports the proposed fibrotic pathology of glaucoma. Regulation of MMP2/ TIMP2 expression and anti-CTGF therapy may offer potential therapeutic avenues for controlling glaucoma

Outcome of pain management with neuroaxial opiates and local anesthetics after cesarean section

Postoperative pain produces adverse physiologic effects with manifestations on multiple organ system. Techniques using a combination of local anesthetic as ropivacaine and opioids have proved to be the most satisfactory in the majority of parturients undergoing cesarean section, because of improved intraoperative comfort. The present study aimed to compare the postoperative analgesic properties of fentanyl and morphine in conjunction with ropivacaine when administrated at apparently optimum dosage. Forty fife female patients were randomly classified into 3 groups. Group I: It consists of 15 patients who received intrathecal ropivacaine 18 mg [2.5 ml] +lml saline 0.9%, all in total volume 3.5 ml. Group II: it consists of 15 patients who received intrathecal ropivacaine 18 mg [2.5 ml] + 300 micro g morphine [1ml], all in total volume 3.5 ml. Group III: it consists of 15 patients who received intrathecal ropivacaine 18 mg [2.5 ml] +20 micro g fentanyl [1ml], all in total volume 3.5 ml. Spinal anesthesia was done to each group by 22gauge pencil-point spinal needle, using midline approach at the level of inters pace L3-4. The study drug was injected at a rate of approximately 0.2ml /sec. maternal mean arterial blood pressure [base line and every 5 minutes until arterial blood pressure became stable then every 1 hour]. Assessment of the neonatal Apgar scores at 1 and 5 min after delivery. Assessment of the onset time to sensory block, maximum sensory level, and time to sensory recovery to L5 was done. Assessment of the motor block was done immediately after sensory block using modified Bromage scale. Also motor block time was recorded. Nausea and vomiting were assessed by ordinal scale. Sedation was assessed by sedation scale. Other complications e.g. respiratory complications and pruritis were recorded. Stability of blood pressure was observed in the three groups. The maximal height of sensory block was similar in the three groups [T2 to T3]. All patients developed complete motor block of lower extremities [Bromage scale, 3] after 3.64 +/- 0.41, 3.51 +/- 0.48 and 3.66 +/- 0.44 minutes in the control, fentanyl and morphine groups respectively. The time required for complete motor recovery was not significant between the three groups, which were ranged from 123.16 to 127.46 minutes. The overall quality of intraoperative analgesia as regarding the time of the first pain sensation, post-spinal injection, was significantly better in the fentanyl [207.32 +/- 24.29 minutes] and morphine [130.18 +/- 20.33 minutes] groups compared with the control group [101.67 +/- 7.56 minutes], [P< 0.05]. There were no patients either in the fentanyl or in the morphine group's required supplementary intraoperative analgesia compared with 3 patients in the control group [P< 0.05]. Regarding the neonatal Apgar score after 1 and 5 minutes, there were no different between the three groups. In the all neonates, the Apgar score was ranging between 8-10. As regard sedation score statistically significant difference between morphine and fentanyl groups and the control group was observed. Addition of both morphine and fentanyl to local anesthetics increased its analgesic efficacy. Morphine was superior to fentanyl as it produces long-term analgesia while fentanyl caused short-term analgesia. Fentanyl may be recommended as an efficient analgesic with less side effects than morphine when injected intrathecally. Both morphine and fentanyl had no effect on neonatal Apgar scores