Threefold Increase in the Number of Drug Resistant TB Cases after Introduction of Universal Drug Susceptibility Testing: Experiences from Two South India Districts

Background: In India, tuberculosis (TB) is a major public health problem, and the advent of drug resistance TB (DR-TB) has worsened the situation. The Revised National TB Control Programme (RNTCP) has introduced universal drug susceptibility testing (UDST) for all diagnosed TB cases in 2018. We conducted this study to know the advantage of implementing UDST when compared to selective testing existent in 2017 on key diagnostic cascade parameters and to identify the challenges in the implementation of UDST. Methods: The study was conducted in two districts of Karnataka, India during January 2017-December 2018. The quantitative part consisted of before-and-after design and the qualitative part consisted of descriptive design. Results: In 2017 (during selective testing/“before” period) out of the 2440 TB patients, 80 (3%) were diagnosed with Isoniazid and Rifampicin resistance patients;in contrast in 2018 (during UDST/“after” period) of the 5129 TB patients 258 (5%) were diagnosed with Isoniazid and Rifampicin resistance. However, the proportion of eligible patients tested for rifampicin resistance during the “after” period was 60% when compared to 100% during the “before” period and median turnaround time for testing was also longer during the “after” period when compared to the “before” period (32.5 days vs 27.5 days). Major reasons for these two gaps were found to be difficulties in collecting sputum specimens and transportation. Conclusion: The rollout of UDST has led to a three-fold increase in a number of DR-TB cases detected in the region. There is a need for the programme to increase the proportion tested for DST by increasing the laboratory capacity and address the challenges in sputum collection and transportation.

Transplantation of human hepatocytes into tolerized genetically immunocompetent rats

AIM: To determine whether normal genetically immunocompetent rodent hosts could be manipulated to accept human hepatocyte transplants with long term survival without immunosuppression. METHODS: Tolerance towards human hepatocytes was established by injection of primary human hepatocytes or Huh7 human hepatoma cells into the peritoneal cavities of fetal rats. Corresponding cells were subsequently transplanted into newborn rats via intrasplenic injection within 24h after birth. RESULTS: Mixed lymphocyte assays showed that spleen cells from non-tolerized rats were stimulated to proliferate when exposed to human hepatocytes, while cells from tolerized rats were not. Injections made between 15 d and 17 d of gestation produced optimal tolerization. Transplanted human hepatocytes in rat livers were visualized by immunohistochemical staining of human albumin. By dot blotting of genomic DNA in livers of tolerized rats 16 weeks after hepatocyte transplantation, it was found that approximately 2.5 X 10(5) human hepatocytes survived per rat liver. Human albumin mRNA was detected in rat livers by RT-PCR for 15 wk, and human albumin protein was also detectable in rat serum. CONCLUSION: Tolerization of an immuno-competent rat can permit transplantation, and survival of functional human hepatocytes.

Epidemiology of Nosocomial Bacteremia Due to Bacteria from the “<i>Burkholderia cepacia</i>Complex” at Libreville University Hospital Center

Introduction: Burkholderia cepacia is a non-fermenting emergent bacterium common in nosocomial infections and can cause life-threatening infections whose multidrug resistance makes them a serious threat in hospitals. The aim of this study was to determine the prevalence of B. cepacia infections during nosocomial infections at Libreville University teaching hospital. Methodology: In this cross-sectional study, lasting 19 months, 412 blood cultures were analyzed. The BacT/ALERT 3D (Biomerieux, France) was used to detect the positivity of blood culture flasks and the Viteck 2 compact (Biomerieux, France) for the identification of germs and the study of their susceptibility to antibiotics. Results: Our study population consisted of 412 patients. The sex-ratio M/F was 1.06 in favor of the male gender (n = 201, 51%). The age of the patients varied between 0 and 82 years. The bacteremia of B. cepacia mainly affected children under 15 years of age with a prevalence of 7% (n = 28). The pediatric ward was more represented with a frequency of 36% (n = 10). The antibiotic sensitivity profile showed high resistance of 100% for aminoglycosides (amikacin, tobramycin, and gentamycin), tetracycline, beta-lactams (Amoxicillin, Imipenem, Ticarcillin, Cefoxitin and Cefotaxime), and ciprofloxacin. However, four molecules were active on B. cepacia (Levofloxacin 100%, Trimethoprim + sulfamethoxazole 92.3%, ceftazidime 80% and cefepime 35%). Conclusion: Ultimately, infection and multi-resistance due to Burkholderia cepacia calls for a review of hospital hygiene in the pediatric ward and a review of antibiotic therapy in young children.

Transplantation tolerance mediated by regulatory T cells in mice

Background With potent suppressive effect on responder T cells, CD 4 +CD 25 + regulatory T (Treg) cells have become the focus of attention only recently and they may play an important role in transplantation tolerance However, the mechanism of action is not clear This study was designed to assess the possibility of using CD 4 +CD 25 + Treg cells to induce transplantation tolerance and to investigate their mechanism of action KH*2/5DMethods CD 4 +CD 25 + Treg cells were isolated using magnetic cell separation techniques Mixed lymphocyte reactions were used to assess the ability of Treg cells to suppress effector T cells Before skin transplantation, various numbers of CD 4 +CD 25 +Treg cells, which have been induced using complex skin antigens from the donor, were injected into the host mice either intraperitoneally (0 5×10 5, 1×10 5, 2×10 5, 3×10 5, 4×10 5, or 5×10 5) or by injection through the tail vein (5×10 3, 1×10 4, 2×10 4, 5×10 4, 1×10 5, 2×10 5) Skin grafts from two different donor types were used to assess whether the induced Treg cells were antigen-specific The survival time of the allografts were observed Single photon emission computed tomography was also used to determine the distribution of Treg cells before and after transplantation Results Treg cells have suppressive effect on mixed lymphocyte reactions Grafts survived longer in mice receiving CD 4 +CD 25 + Treg cell injections than in control mice There was a significant difference between groups receiving intraperitoneal injection of either 2×10 5 or 3×10 5 CD 4 +CD 25 +Treg cells and the control group ( P <0 05, respectively) Better results were achieved when Treg cells were injected via the tail vein than when injected intraperitoneally The transplantation tolerance induced by CD 4 +CD 25 + Treg cells was donor-specific Analysis of the localization of Treg cells revealed that Treg cells mainly migrated from the liver to the allografts and the spleen KH*2/5DConclusions CD 4 +CD 25 +Treg cells can induce donor-specific transplantation tolerance Cell-to-cell contact may be the primary mechanism by which Treg cells act on effector T cells