Frequency and Geographic Distribution of <i>gyrA</i> and <i>gyrB</i> Mutations Associated with Fluoroquinolone Resistance in Clinical <i>Mycobacterium Tuberculosis</i> Isolates: A Systematic Review

<div><p>Background</p><p>The detection of mutations in the <i>gyrA</i> and <i>gyrB</i> genes in the <i>Mycobacterium tuberculosis</i> genome that have been demonstrated to confer phenotypic resistance to fluoroquinolones is the most promising technology for rapid diagnosis of fluoroquinolone resistance.</p><p>Methods</p><p>In order to characterize the diversity and frequency of gyrA and gyrB mutations and to describe the global distribution of these mutations, we conducted a systematic review, from May 1996 to April 2013, of all published studies evaluating Mycobacterium tuberculosis mutations associated with resistance to fluoroquinolones. The overall goal of the study was to determine the potential utility and reliability of these mutations as diagnostic markers to detect phenotypic fluoroquinolone resistance in Mycobacterium tuberculosis and to describe their geographic distribution.</p><p>Results</p><p>Forty-six studies, covering four continents and 18 countries, provided mutation data for 3,846 unique clinical isolates with phenotypic resistance profiles to fluoroquinolones. The gyrA mutations occurring most frequently in fluoroquinolone-resistant isolates, ranged from 21–32% for D94G and 13–20% for A90V, by drug. Eighty seven percent of all strains that were phenotypically resistant to moxifloxacin and 83% of ofloxacin resistant isolates contained mutations in gyrA. Additionally we found that 83% and 80% of moxifloxacin and ofloxacin resistant strains respectively, were observed to have mutations in the gyrA codons interrogated by the existing MTBDR<i>sl</i> line probe assay. In China and Russia, 83% and 84% of fluoroquinolone resistant strains respectively, were observed to have gyrA mutations in the gene regions covered by the MTBDR<i>sl</i> assay.</p><p>Conclusions</p><p>Molecular diagnostics, specifically the Genotype MTBDR<i>sl</i> assay, focusing on codons 88–94 should have moderate to high sensitivity in most countries. While we did observe geographic differences in the frequencies of single gyrA mutations across countries, molecular diagnostics based on detection of all gyrA mutations demonstrated to confer resistance should have broad and global utility.</p></div

Heat map of Reviewed Studies that Evaluated <i>gyrA</i> Gene Mutations in <i>Mtb</i>.

<p>Heat map of individual papers indicating the number of isolates and the region of the <i>gyrA</i> gene studied. The number of isolates testes ranges from 8 (light grey) to 227 (black). Red indicates that a mutation has been found.</p

Individual and community factors contributing to anemia among women in rural Baja California, Mexico

<div><p>Introduction</p><p>Anemia is a public health concern among women in rural Baja California, Mexico. The purpose of this study was to identify the individual and community factors contributing to the disproportionately high prevalence of anemia among women in this region.</p><p>Methods</p><p>A cross-sectional study of 118 women (15–49 years) was performed in a rural <i>colonia</i> (small settlement) in Baja California, Mexico in 2012. Participants completed a survey comprised of demographic, socioeconomic, health, and dietary questions and provided a capillary blood sample. A portable HemoCue was used to measure hemoglobin and diagnose anemia. Anemic participants provided a venous blood sample for laboratory testing to elucidate the etiology of anemia. Anemic participants received vitamin supplements and nutritional counseling. Assessments of six local <i>tiendas</i> (community grocery stores) were performed to ascertain the types of food available for purchase within the community.</p><p>Results</p><p>Prevalence of anemia was 22% among women; laboratory tests revealed iron deficiency was the primary etiology in 80.8% of anemia cases. Other causes of anemia in women included vitamin B-12 deficiency (11.5%) and combined iron and vitamin B-12 deficiency (7.7%). Women from low SES households and women enrolled in the government assistance program <i>Prospera</i> were significantly more likely to be anemic (OR = 3.48, 95% CI 1.35–8.98 and OR = 2.49, 95% CI 1.02–6.09, respectively). Vitamin supplementation was significantly more common among non-anemic women (OR = 0.12, 95% CI 0.02–0.94). Dietary assessments showed limited consumption of iron absorption enhancing foods such as fruits and vegetables. Assessments of local <i>tiendas</i> revealed at least one type of meat and citrus fruit available for purchase at each store; however, leafy green vegetables were only available for purchase at one store.</p><p>Conclusion</p><p>All cases of anemia were due to nutritional deficiencies. While vitamin supplementation is a temporary solution, improved individual nutrition knowledge and community access to iron absorption enhancing foods, particularly produce, is needed. Promoting government assistance programs like <i>Prospera</i> and implementing additional programs designed to improve nutrition and health literacy, in conjunction with ensuring access to nutritious foods, might reduce the high prevalence nutritional anemia within the community.</p></div

Associations between demographic, SES, and health variables and anemia status in women living in a rural farming community in Baja California, Mexico [2012] (n = 118).

<p>Associations between demographic, SES, and health variables and anemia status in women living in a rural farming community in Baja California, Mexico [2012] (n = 118).</p

Etiology of anemia among women in a rural farming community of northern Baja California, Mexico [2012] (n = 26).

<p>Etiology of anemia among women in a rural farming community of northern Baja California, Mexico [2012] (n = 26).</p

Prevalence and severity of anemia in women living in a rural farming community in Baja California, Mexico [2012].

<p>Prevalence and severity of anemia in women living in a rural farming community in Baja California, Mexico [2012].</p