ABSTRACT
Heterogeneous, intermediate-vancomycin-resistant Staphylococcus aureus (hVISA) represents a threat of an incurable infection since the first report in 1997. The method used to detect hVISA isolates is a population analysis profile (PAP); however, it is impractical for routine laboratory analysis. We therefore tested a simple, reliable and inexpensive method for the detection of hVISA. Eighteen isolates of hVISA and 22 of vancomycin-sensitive S. aureus (VSSA) were included. The organisms were tested by the disk diffusion method, using 15-microg vancomycin disks on four different media: Mueller-Hinton agar (MHA), MHA plus 2% NaCI (MHAS), Brain Heart Infusion agar (BHA), and BHA plus 2% NaCl (BHAS). In addition, two different inoculum sizes, bacterial suspensions adjusted to 0.5 and 2.0 McFarland, were tested. The inhibition zone was read independently by three medical technologists after incubation at 37 degrees C for 24 and 48 hours. The use of MHAS with an inoculum size of 2.0 McFarland and 48-hour incubation period yielded the highest sensitivity (94.4%), specificity (81.8%), positive predictive value (80.9%), and negative predictive value (94.7%). The disk diffusion test with 15-microg vancomycin disk is simple and may be used as a screening method for the detection of hVISA.
Subject(s)
Culture Media , Disk Diffusion Antimicrobial Tests/methods , Predictive Value of Tests , Sensitivity and Specificity , Staphylococcus aureus/isolation & purification , Vancomycin ResistanceABSTRACT
Brucellosis is a zoonotic disease prevalent in many countries, but it has been reported only once in Thailand, 36 years ago. We describe here two consecutive cases of brucellosis in Bangkok, Thailand. Both cases presented with prolonged fever and weight loss. Blood cultures taken from 2 patients yielded Brucella melitensis. The slide agglutination test of blood samples were also positive, with a titer of 1:64 for antibodies to Brucella. The first patient responded to a combination of doxycycline, gentamicin, and ciprofloxacin; the other responded to doxycycline and rifampicin. Brucellosis is a potential public health threat, therefore, preventive measures should be actively implemented. This clinical syndrome should be included in the differential diagnosis of patients presenting with prolonged fever, particularly those with contact to animals which could serve as reservoirs.
Subject(s)
Adult , Agglutination Tests , Anti-Bacterial Agents , Biopsy, Needle , Brucella melitensis/isolation & purification , Brucellosis/diagnosis , Communicable Diseases, Emerging/diagnosis , Drug Therapy, Combination/therapeutic use , Follow-Up Studies , Humans , Immunohistochemistry , Male , Middle Aged , Risk Assessment , Severity of Illness Index , Thailand , Treatment OutcomeABSTRACT
A 35-year-old woman who presented with acute purulent meningitis and hearing loss was reported. No bacteria was seen with Gram' s stain of cerebrospinal fluid (CSF). CSF grew Streptococcus viridans, which was subsequently identified to be S. sanguis. The patient improved after treatment, including hearing.