Serum Levels of Interferon Gamma in Patients with Brucellosis in a Saudi Hospital.

Background: Brucellosis is a major zoonotic disease that is endemic in Saudi Arabia and it remains a major health problem that has not been eradicated in the country yet. Place and Duration of Study: This retrospective study was conducted in a Saudi Hospital at Al Madinah city during the period of 1 November, 2010 to 31 October, 2011. Methodology: All sera of patients suspected to have brucellosis (n= 65) and 18 healthy subjects were tested for brucella antibody using slide latex agglutination (SAT) and ELISA. Quantitation of IFN-ɣ was also done using ELISA. Results: Brucellosis was detected in all age groups but the incidence was higher and reached 33.3% in age group (40- <50) years with average of 43.9±2.53 years. Male to female ratio in infected patients was 2:1 by using SAT. The incidence of seropositive cases was high (80.1%) in the three months (April, May and June), with the highest peak in May (46.7%). Drinking raw milk was the most encountered risk factor with a prevalence of 66.1% followed by consumption of milk products (11.9%). The most prevalent species among the examined cases was B. melitensis (93.3%). Among the studied cases, 60 cases (92.3%) were serologically positive for brucellosis by SAT. Among the 60 cases yielding significant titers against brucella, 14 sera (23.3%) had agglutinin levels of 1:80, 34 sera (56.7%) had titers of 1:160 and 12 sera (20%) had titers of 1:320. By estimating IgM and IgG levels in the sera of examined cases using ELISA, 52 cases (80%) had brucellaIgM while 42 cases (64.6%) had brucella IgG. Sensitivities of SAT, IgM ELISA and IgG ELISA were 91.5%, 88.1% and 71.2%, respectively compared with combined ELISA. Mean IFN-ɣ levels ± SD in the subacute phase was 136.7±70.07pg/ml, 120.2±54.25pg/ml in the acute phase, and 121.3±51.09 pg/ml in the chronic phase of brucellosis. Conclusion: The sensitivity and specificity of ELISA to diagnose human brucellosis was higher when combined ELISA (IgM/IgG or both) was used. Mean IFN-ɣ levels were lower, but not significantly, in the chronic phase of the disease than in the sub acute phase and healthy subjects.

Comparison of four methods for rapid identification of Staphylococcus aureus directly from BACTEC 9240 blood culture system.

Purpose: Differentiation of Staphylococcus aureus (S. aureus) from coagulase-negative staphylococci is very important in blood stream infections. Identification of S. aureus and coagulase-negative staphylococci (CoNS) from blood cultures takes generally 18-24 h after positive signaling on continuously monitored automated blood culture system. In this study, we evaluated the performance of tube coagulase test (TCT), slide agglutination test (Dry Spot Staphytect Plus), conventional polymerase chain reaction (PCR) and LightCycler Staphylococcus MGrade kit directly from blood culture bottles to achieve rapid identification of S. aureus by using the BACTEC 9240 blood culture system. Materials and Methods: A total of 129 BACTEC 9240 bottles growing gram-positive cocci suggesting Staphylococci were tested directly from blood culture broths (BCBs) with TCT, Dry Spot Staphytect Plus, conventional PCR and LightCycler Staphylococcus MGrade kit for rapid identification of S. aureus. Results: The sensitivities of the tests were 99, 68, 99 and 100%, respectively. Conclusion: Our results suggested that 2 h TCT was found to be simple and inexpensive method for the rapid identification of S. aureus directly from positive blood cultures.