Microbiologie médicale et diagnostic

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Colostrum was shown to protect children against gastrointestinal and respiratory infections and to exhibit chronobiological variations in cellular and soluble components. However, circadian variations in the activity of these colostral elements are only partially understood. This study compared colostrum samples collected in the diurnal and nocturnal periods by assessing phagocytic activity against enteropathogenic Escherichia coli (EPEC) and Streptococcus pneumoniae ( S. pneumoniae ) as well as the role of colostral cells and soluble elements. Colostrum samples were collected from 30 mothers during both day and night. Superoxide anion release, phagocytosis and bactericidal activity by colostral mononuclear (MN) and polymorphonuclear (PMN) phagocytes in the presence of EPEC or S. pneumoniae were determined. Colostrum samples collected in the diurnal period had higher superoxide release in opsonized than in non-opsonized EPEC and S. pneumoniae , whereas in nocturnal samples it was increased in PMN phagocytes incubated with serum-opsonized S. pneumoniae . MN and PMN phagocytes in colostrum collected in both periods exhibited phagocytic activity for the bacteria tested. The highest EPEC killing by MN phagocytes was observed in samples collected in the diurnal period. The bactericidal activity of PMN phagocytes against EPEC was higher when bacteria were opsonized and in samples collected in the diurnal period. For opsonized S. pneumoniae , phagocytes had similar bactericidal activity, irrespective of colostrum collection period. These data support the hypothesis that there is a fluctuation in the functional activity of colostral phagocytes, which is dependent on synchronization among feeding time, pathogen features and infection area.

Human Immunodeficiency Virus (HIV) infection, with the complexity of disease and its progression has become a challenge to human beings. HIV infection leads to variable disease course in different people, amongst them are long term non-progressors, who survive more than 10 years after getting infected. Due to the chronicity of the disease and the extent of morbidity it causes, management of such individuals has become a challenge for physicians treating HIV infected patients. Traditionally HIV disease progression is monitored using TCD4+ cell counts and HIV/RNA viral load. Resource poor countries which cannot afford such expenses are looking forward to tests that can be done easily and are cost effective to monitor HIV disease progression and treatment response. We therefore evaluated certain biochemical parameters in both HIV seropositive treatment naive and those on HAART. Significant differences are observed in the plasma concentration of CK-MB (p<0.01), AST (p<0.05), LDH (p<0.01), Total Cholesterol: HDL ratio were (p<0.001), HDL:LDL ratio (p<0.001), A/G ratio (p<0.001), ALT (p<0.02), Serum Albumin (p<0.001), and Serum Globulin (p<0.001) levels. Serum albumin (r = -0.191), Albumin:Globulin ratio (r= -0.162), Total protein (r= -0.029), LDH (r= -0.264), CK/MB (r= -0.027), HDL (r= -0.0380 and LDL:HDL ratio (r= -0.032) were found negatively correlating with TCD4+ cell counts in HIV seropositive patients who are antiretroviral therapy naive. A paired t test of various parameters before and after HAART showed significant results with TCD4+ cells (p <0.0001), CK/MB ( p= 0.0451) and LDL:HDL ratio (p=0.0341). The results reemphasize the significance of evaluating certain biochemical parameters in HIV seropositive individuals and their usefulness in the management of disease progression and treatment response.

Background/Objective:The present study was conducted to assess the seroprevalence of Toxoplasma gondiiin and around Tirunelveli, Tamil Nadu, India by in-house IgG assay, using MAT.

Methods:Serum samples from 175 immunodeficient and 175 immunocompetent patients were collected at Tirunelveli District, Tamil Nadu from May 2006 to October 2007. They were subjected to in-house IgG assay using Modified Direct Agglutination test (MAT).

Results:Out of 350 patients tested by MAT, 39 patients (11.41%) had antibodies for toxoplasmosis with mean MAT titre of 53.85 ± 55.28 and the titre ranged from 1:20 to 1:160. Among the immunocompetent group of 175 patients, 18 patients (10.29%) had antibodies to toxoplasmosis whereas in immunodeficient group of 175 patients, 21 patients (12%) had antibodies for toxoplasmosis. The sensitivity, specificity of IgG MAT in detecting toxoplasmosis was 80 and 90 % respectively.

Statistical analysis: The results were analysed by using the statistical software SPSS.

Conclusions:The overall seroprevalence of toxoplasmosis in and around Tirunelveli District of Tamil Nadu was 11.41% based on IgG MAT. The study has proved that MAT is recommended as the most convenient method for serodiagnosis of toxoplasmosis and has the additional advantage of not requiring species-specific conjugates.

Background/Objective : Febrile illnesses have continued to escalate in South-Western Uganda despite using many multidisciplinary studies and interventions (weakened by poor resources) to control the syndrome. To appraise the burden of typhoid in regional febrile illnesses, this laboratory based retrospective analytical study was undertaken to outline the distribution of community acquired typhoid fever among febrile patients attending clinics in Bushenyi, Uganda.

Methods: After ethical approval and with standard methods, six hundred and eighty seven data-files (311 from males and 376 from females) of recruited febrile, typhoid positive hospital attendees in Bushenyi were analyzed with particular attention to socio-demographic impact on typhoid distribution.

Results: From the age bracket 10-19 years, males, with 36.6% typhoid, attending Bushenyi Medical center and females, with 33.8% typhoid attending Comboni hospital had the highest typhoid distribution in this survey. Other results include males: 10-19years and above 60 years old from Comboni hospital with 28.6% and 22.2% typhoid distribution, including 24.6% typhoid distribution shown among males 20-29years old attending Ishaka Adventist Hospital. However, females above 60years and 10-19 years old attending Bushenyi medical center had 32.8% and 25% typhoid distribution respectively; including 24.7% typhoid among females aged 20-29years old, attending Comboni hospital. Typhoid: was highest in the low-income class, lowest in the high-income class and uniformly distributed from January to December.

Conclusions: Typhoid is highly (36.6%) prevalent among febrile patients aged (10-29 years old) attending clinics in Bushenyi and spread depends on age, sex, socio-economic status and season. The strategic impact of typhoid on the teenage and early adulthood aged- 10-29 years is noteworthy. Hygiene education and monitoring of the street-food trade are recommended typhoid control measure.