ABSTRACT
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
ABSTRACT
Background: Pandrug resistant Gram-negative organisms [PDRGNs] have emerged, as a major threat to hospitalized patients. They have been associated with mortality rates ranging from 30 to 70%. Because of the high morbidity and mortality rates of severe pandrug resistant acinetobacter spp infections, combination therapies, as opposed to monotherapy, are suggested. A synergistic effect may be developed when antibiotics are used in combination. Through this synergistic effect, treatment efficacy can be improved and resistance can be prevented
Aim of the work: To investigate the use of in vitro antibiotic synergy test [checkerboard] for pandrug resistant acinetobacter species with a clinical feedback on the most synergistic antimicrobial combination
Materials and Methods: During this study, one hundred isolate of drug resistant acinetobacter species identified by routine culture and sensitivity using disc diffusion susceptibility test, were collected from critically ill patients admitted to Ain Shams University Internal Medicine Intensive Care Units. The isolates were subjected to: [i] Determination of MIC using Vitek 2 automated system to confirm resistance of acinetobacter species to all commercially available antibiotics, [ii] Broth micro-dilution method [BMD] for determination of tigecycline susceptibility, and [iii] Determination of antimicrobial synergy by broth micodilution [Checkerboard method]
Results: Vitek 2 system results showed that, all of the 100 isolates were resistant to all antibiotics included in the study. On the other hand, 100% of the isolates were sensitive [S] to Colistin. As regards the results by Broth microdilution antibiotic susceptibility method, all 100 isolates [100%] were resistant to ampicillin/sulbactam, meropenem and ciprofloxacin, whereas 95 isolates [95%] were resistant to amikacin, whereas all 100 isolates [100%] tested were sensitive to tigecycline. The results of the antibiotic combinations were as follows; the activity of ampicillin/sulbactam in combination with amikacin showed synergy in [48%], addition in [42%] and indifference in [10%]. The activity of ampicillin/sulbactam in combination with ciprofloxacin showed, synergy in [36%], addition in [52%] and indifference in [12%]. The activity of meropenem in combination with amikacin showed, synergy in [26%], addition in [53%] and indifference in [21%]. No antagonistic activity was detected between any of the antibiotic combinations used
Conclusion: The prevalence of XDR/PDR resistant Acinetobacter spp. was highest in blood samples [43%] followed by sputum samples [35%] recovered from critically ill patients admitted to Ain Shams University Internal Medicine Intensive Care Units. Vitek 2 system showed that, all of the 100 isolates were resistant to all antibiotics included in the study. On the other hand, 100% of the isolates were sensitive [S] to colistin. Broth microdilution antibiotic susceptibility method showed that, all 100 isolates [100%] were resistant to ampicillin/sulbactam, meropenem and ciprofloxacin, whereas 95 isolates [95%] were resistant to amikacin, whereas all 100 isolates [100%] tested were sensitive to tigecycline, indicating that acinetobacter spp. did not attain resistance to tigecycline yet. The broth microdilution antibiotic synergy test [Checkerboard method], being the reference method for assessing antimicrobial synergy, showed that the highest synergic activity belongs to ampicillin/sulbactam and amkacin [48%], and the lowest synergic activity belongs to meropenem and amikacin [26%]
ABSTRACT
Background: Infections of central nervous system [CNS], such as encephalitis, meningitis, and meningoencephalitis are potentially life-threatening syndromes. They are caused by a diverse array of infectious causes. Despite being relatively uncommon, the morbidity, mortality, and costs are substantial. Of major importance are the herpes simplex virus [HSV]-2 and varicella zoster virus [VZV] in meningitis, and HSV-1 in encephalitis. Human herpes virus 6 [HHV-6] infection can induce severe encephalitis cases, particularly in immunocompromised. Human herpes viruses [HHVs] can cause CNS disease following primary infection, reactivation or recurrence
Purpose: To estimate the frequency of four common neurotropic herpes viruses: HHV-1 [HSV-1], HHV-2 [HSV-2], HHV-3 [VZV] and HHV-6 as causative agents for viral encephalitis and aseptic meningitis
Patients and Methods: The study was conducted on sixty five [65] CSF samples selected from the CSF of patients clinically diagnosed with acute encephalitis or meningitis. The samples belonged to 39[60.0%] males and 26[40.0%] females. Their ages ranged from 12 days to 62 years old. All CSF samples included in the study were subjected to white cell count, estimation of the level of protein and glucose, direct macroscopic and microscopic examination and culture on blood, chocolate and MacConkey agar plates. All samples had a CSF leukocytic count >/= 5 cells/ mm3 and all were negative for bacterial culture. Real time PCR for the following viruses: HHV-1 [HSV-1], HHV-2 [HSV-2], HHV-3 [VZV] and HHV-6 was done for each sample
Results: The results of the PCR showed that twenty six [40%] were positive: twenty two [34%] were positive for a single infection; HSV-1 was positive in seven [10.8%], HSV-2 in eight [12.3%], VZV in one [1.5%] and HHV-6 in six [9.2%] of the cases. Four [6.2%] samples showed co-infection with two viruses. VZV was common in all cases of co-infection, together with HSV-2 in two [3%], HSV-1 in one [1.5%] and HHV-6 in one [1.5%]. Thirty nine cases [60.0%] were negative for the four viruses
Conclusion: The four herpes viruses [HSV-1, HSV-2, VZV and HHV-6] tested by PCR are causative agents in 40% of the tested cases of CNS infections. The most frequently detected virus by PCR was HSV-2 followed by HSV-1. In case of encephalitis, the most frequently detected virus was HSV-1, while HSV-2 was the most frequent in case of aseptic meningitis. VZV was common in all cases of co-infections
ABSTRACT
Background: Dermatophytes are responsible for the majority of the fungal infections involving skin, hair and nails. There has been a remarkable increase in the number of fungal infections especially in those people whose immune system is compromised by aging, HIV infection, organ transplantation or cancer therapy
Objective: The aim of this study was to compare both broth microdilution method and disk diffusion method for in-vitro activity of some antifungal drugs [Terbinafine, Fluconazole, Itraconazole] against different species of dermatophytes
Patients and Method: This study was performed on 50 dermatophyte isolates recovered from various clinical specimens [skin, hair and nail] collected from dermatology outpatient clinic of Ain Shams University Hospital. All samples were cultured on sabarouds. Isolates recovered from SDA were subcultured on Potato Dextrose Agar [PDA] and incubated at 28 degree C for 7 days to enhance sporulation. The growth was harvested in sterile saline and the conidial and hyphal suspension was adjusted to 0.5 macfarland. Then antifungal susceptibility was done using: Disk diffusion [DD] method and Broth micro dilution [BMD] method
Results: There was a highly significant agreement between the antifungal susceptibility testing of fluconazole, itraconazole and terbinafine by disk diffusion method and Broth micro-dilution method. In our study agreement between both methods for itraconazole was 1.00 [kappa], for terbinafine was 0.947, and for fluconazole was 0.878. The factors that may affect the results of BMD or DD are type and size of inoculum, composition of the media, temperature and duration of incubation and disc strength
Conclusion: There was a highly significant agreement between the antifungal susceptibility testing of fluconazole, itraconazole and terbinafine by disk diffusion method and Broth micro-dilution method