Impact of Mycobacterium tuberculosis complex lineages as a determinant of disease phenotypes from an immigrant rich moderate tuberculosis burden country.

BACKGROUND: Growing evidences suggested that the Mycobacterium tuberculosis complex (MTBC) lineages can determine the clinical outcome of pulmonary and extra-pulmonary tuberculosis. However, limited data only available revealing such association of bacterial genotypes and clinical phenotypes from immigrant rich countries. METHODS: A multicenter study has been carried out on a collection of 2092 (1003 extrapulmonary and 1089 pulmonary) MTBC isolates. Genotyping of all the isolates were carried out by spoligotyping and 24 loci based MIRU-VNTR typing. RESULTS: Demographically domination of young Saudi nationals (61.4%) and men (61.2%) were found in this cohort. Lymph nodes (62.4%) and gastrointestinal sites (16.7%) were the most common anatomical sites of infection. The predominant lineages were Delhi/CAS (26.9%), EAI (14.2%) and Ghana (9.9%). Mycobacterium africanum type I and II were reported for the first time in the country among extrapulmonary cases. 'Ancestral' lineages M.bovis (OR-5.22; 95% CI-2.23-8.22, p- < 0.001) and Delhi/CAS (OR-0.57; 95% CI-0.411-0.734, p- < 0.001) were directly associated with lymph node tuberculosis and gastrointestinal tuberculosis (M. bovis-OR-0.33; 95% CI-0.085-0.567, p-0.001 and Delhi/CAS-OR-1.87; 95% CI-1.22-2.53, p- < 0.001) respectively. Among the 'Modern' lineages, EAI showed significant association to central nervous system tuberculosis (OR-1.98; 95% CI-0.76-3.19, p-0.04) and Uganda-I to gastrointestinal tuberculosis (OR-2.41; 95% CI-0.77-4.06, p-0.02). CONCLUSIONS: The findings substantially contribute to the emerging evidences that MTBC lineages influence disease phenotypes and epidemiological consequences.

Diagnostic potential of interferon-gamma release assay to detect latent tuberculosis infection in kidney transplant recipients.

BACKGROUND: Latent tuberculosis (TB) infection (LTBI) is screened by using clinical assessment, tuberculin skin test (TST), chest radiography, and recently by interferon-gamma release assays (IGRA). The objective of this study was to evaluate the diagnostic potential of QuantiFERON® -TB Gold In-Tube test (QFT) for diagnosing LTBI in patients planned for kidney transplantation. METHODS: All adult patients with end-stage renal disease, evaluated for kidney transplantation in a referral center from August 2008 till May 2013, were enrolled, after consenting in a prospective, observational, non-interventional study. LTBI diagnosis was conducted by TST, chest x-ray, and clinical assessment, followed by IGRA by QFT. RESULTS: Overall, 278 patients were enrolled and kidney transplantation was performed in 173 patients. Contributed follow-up was 836.5 patient-years, and TB-free transplant duration was 478.5 patient-years. By standard methods, LTBI was diagnosed in 14 patients. Peri-transplant chemoprophylaxis was given to 53 patients, which included recipients of organs from all deceased donors and living donors with LTBI. QFT was positive in 70 patients, negative in 200 patients, and indeterminate in 8 patients. The agreement between LTBI diagnosis using standard methods and IGRA by QFT was poor (kappa: 0.089+0.046, P-value=.017). Twenty-seven of the QFT-positive patients were transplanted and only one was given isoniazid preventive therapy. None of the transplant recipients developed TB after a median follow-up of 25 months (range 2-58 months, mean 27 months). CONCLUSIONS: The agreement of the QFT with standard diagnosis of LTBI in kidney transplant recipients was poor.

Epidemiology of antituberculosis drug resistance in Saudi Arabia: findings of the first national survey.

The real magnitude of antituberculosis (anti-TB) drug resistance in Saudi Arabia is still unknown because the available data are based on retrospective laboratory studies that were limited to hospitals or cities. A representative national survey was therefore conducted to investigate the levels and patterns of anti-TB drug resistance and explore risk factors. Between August 2009 and July 2010, all culture-positive TB patients diagnosed in any of the tuberculosis reference laboratories of the country were enrolled. Isolates obtained from each patient were tested for susceptibility to first-line anti-TB drugs by the automated Bactec MGIT 960 method. Of the 2,235 patients enrolled, 75 cases (3.4%) were lost due to culture contamination and 256 (11.5%) yielded nontuberculous mycobacteria (NTM). Finally, 1,904 patients (85.2% of those enrolled) had available drug susceptibility testing results. Monoresistance to streptomycin (8.1%; 95% confidence interval [CI], 7.2 to 9.1), isoniazid (5.4%; 95% CI, 4.7 to 6.2), rifampin (1%; 95% CI, 0.7 to 1.3) and ethambutol (0.8%; 95% CI, 0.5 to 1.2) were observed. Multidrug-resistant TB (MDR-TB) was found in 1.8% (95% CI, 1.4 to 2.4) and 15.9% (95% CI, 15.4 to 16.5) of new and previously treated TB cases, respectively. A treatment history of active TB, being foreign-born, having pulmonary TB, and living in the Western part of the country were the strongest independent predictors of MDR-TB. Results from the first representative national anti-TB drug resistance survey in Saudi Arabia suggest that the proportion of MDR-TB is relatively low, though there is a higher primary drug resistance. A strengthened continuous surveillance system to monitor trends over time and second-line anti-TB drug resistance as well as implementation of innovative control measures, particularly among immigrants, is warranted.

Sex-dimorphism in cardiac nutrigenomics: effect of trans fat and/or monosodium glutamate consumption.

BACKGROUND: A paucity of information on biological sex-specific differences in cardiac gene expression in response to diet has prompted this present nutrigenomics investigation. Sexual dimorphism exists in the physiological and transcriptional response to diet, particularly in response to high-fat feeding. Consumption of Trans-fatty acids (TFA) has been linked to substantially increased risk of heart disease, in which sexual dimorphism is apparent, with males suffering a higher disease rate. Impairment of the cardiovascular system has been noted in animals exposed to Monosodium Glutamate (MSG) during the neonatal period, and sexual dimorphism in the growth axis of MSG-treated animals has previously been noted. Processed foods may contain both TFA and MSG. METHODS: We examined physiological differences and changes in gene expression in response to TFA and/or MSG consumption compared to a control diet, in male and female C57BL/6J mice. RESULTS: Heart and % body weight increases were greater in TFA-fed mice, who also exhibited dyslipidemia (P < 0.05). Hearts from MSG-fed females weighed less than males (P < 0.05). 2-factor ANOVA indicated that the TFA diet induced over twice as many cardiac differentially expressed genes (DEGs) in males compared to females (P < 0.001); and 4 times as many male DEGs were downregulated including Gata4, Mef2d and Srebf2. Enrichment of functional Gene Ontology (GO) categories were related to transcription, phosphorylation and anatomic structure (P < 0.01). A number of genes were upregulated in males and downregulated in females, including pro-apoptotic histone deacetylase-2 (HDAC2). Sexual dimorphism was also observed in cardiac transcription from MSG-fed animals, with both sexes upregulating approximately 100 DEGs exhibiting sex-specific differences in GO categories. A comparison of cardiac gene expression between all diet combinations together identified a subset of 111 DEGs significant only in males, 64 DEGs significant in females only, and 74 transcripts identified as differentially expressed in response to dietary manipulation in both sexes. CONCLUSION: Our model identified major changes in the cardiac transcriptional profile of TFA and/or MSG-fed mice compared to controls, which was reflected by significant differences in the physiological profile within the 4 diet groups. Identification of sexual dimorphism in cardiac transcription may provide the basis for sex-specific medicine in the future.

Robot-assisted pediatric surgery: how far can we go?

BACKGROUND: The purpose of this study was to assess the safety and feasibility of performing robot-assisted pediatric surgery using the da Vinci Surgical System in a variety of surgical procedures. METHODS: A retrospective review of 144 robot-assisted pediatric surgical procedures performed in our institution between June 2004 and December 2007 was done. The procedures included the following: 39 fundoplications; 34 cholecystectomies; 25 gastric bandings; 13 splenectomies; 4 anorectal pull-through operations for imperforate anus; 4 nephrectomies; 4 appendectomies; 4 sympathectomies; 3 choledochal cyst excisions with hepaticojejunostomies; 3 inguinal hernia repairs; two each of the following: liver cyst excision, repair of congenital diaphragmatic hernia, Heller's myotomy, and ovarian cyst excision; and one each of the following: duodeno-duodenostomy, adrenalectomy, and hysterectomy. RESULTS: A total of 134 procedures were successfully completed without conversion; 7 additional cases were converted to open surgery, and 3 were converted to laparoscopic surgery. There were no system failures (e.g., setup joint, arm, or camera malfunction; power error; monocular or binocular loss; metal fatigue or break of surgeon's console hand piece; software incompatibility). There was one esophageal perforation and two cases of transient dysphagia following Nissen fundoplication. The mean patient age was 8.9 years, and the mean patient weight was 57 kg. CONCLUSIONS: Robot-assisted surgery appears to be safe and feasible for a number of pediatric surgical procedures. Further system improvement and randomized studies are required to evaluate the benefits, if any, and the long-term outcomes of robotic surgery.

Sugar-sweetened carbonated beverage consumption correlates with BMI, waist circumference, and poor dietary choices in school children.

BACKGROUND: The prevalence of obesity and overweight is increasing globally. Frequently coexisting with under-nutrition in developing countries, obesity is a major contributor to chronic disease, and will become a serious healthcare burden especially in countries with a larger percentage of youthful population. 35% of the population of Saudi Arabia are under the age of 16, and adult dietary preferences are often established during early childhood years. Our objective was to examine the dietary habits in relation to body-mass-index (BMI) and waist circumference (W_C), together with exercise and sleep patterns in a cohort of male and female Saudi school children, in order to ascertain whether dietary patterns are associated with obesity phenotypes in this population. METHODS: 5033 boys and 4400 girls aged 10 to 19 years old participated in a designed Food Frequency Questionnaire. BMI and W_C measurements were obtained and correlated with dietary intake. RESULTS: The overall prevalence of overweight and obesity was 12.2% and 27.0% respectively, with boys having higher obesity rates than girls (P

Breast arterial calcification on mammography does not predict coronary artery disease by invasive coronary angiography.

BACKGROUND: The relationship between breast arterial calcification (BAC) and angiographic coronary artery disease (CAD) is uncertain. Some studies have shown a positive association between BAC and angiographically proven CAD, while other studies have shown no association. OBJECTIVE: Examine the association between visually detected BAC on mammography and CAD found on invasive coronary angiography (ICA) in women and compare the frequency of risk factors for CAD between women with normal and abnormal ICA. DESIGN: Retrospective. SETTING: Single tertiary care center. PATIENTS AND METHODS: A review of the radiology databases was performed for female patients who underwent both ICA and mammography within six months of each other. Cases were excluded if there was a history of CAD, such as coronary artery bypass graft or prior percutaneous coronary intervention. MAIN OUTCOME MEASURES: BAC as a predictor of obstructive CAD on ICA. SAMPLE SIZE: 203 Saudi women RESULTS: The association between age at catheterization and ICA was statistically significant ( P=.01). There was no association between BAC and abnormal ICA ( P=.108). Women with abnormal ICA were older than women with a normal ICA ( P=.01). There was a higher frequency of CAD risk factors among the patients with abnormal ICA, except for smoking. In the multiple logistic regression model, ICA was associated with age, a family history of CAD, diabetes mellitus, hypertension and hypercholesterolemia. BAC-positive women were older than BAC-negative women ( P=.0001). BAC was associated with age, diabetes, hypertension, and chronic kidney disease in the multiple logistic regression model. CONCLUSIONS: BAC on mammography did not predict angiographically proven CAD. There was a strong association between BAC and age and many other conventional CAD risk factors. LIMITATIONS: Relatively small sample, single-center retrospective study. CONFLICT OF INTEREST: None.

Burden of non-tuberculous mycobacterial diseases in Saudi Arabian children: The first nationwide experience.

BACKGROUND: Non-tuberculous mycobacteria (NTM) causing pulmonary and extra-pulmonary diseases are increasing worldwide. A large paucity of data related to pediatric NTM diseases exists globally and particularly in Saudi Arabia. METHODS: The first nationwide exploratory study on existence of NTM diseases among Saudi Arabian children (0-14 years old) has been carried out during 2016-2017. Suspected NTM isolates with clinical and demographical data were enrolled from regional reference laboratories. Species level identification of isolates was carried out by commercial line probe assays and gene sequencing. RESULTS: In 12 months, 52 culture positive cases with 44(84.6%) confirmed disease incidences were identified. Demographically, Saudi nationals (86.5%) were dominated and 77.3% cases have different comorbid conditions. Lymphadenitis (40.4%) followed by 26.9% of pulmonary cases with 42.8% of confirmed clinical relevance were mainly reported. Species identification showed Mycobacterium simiae (31.8%), M. abscessus (23.1%) and nine other species including rarely encountering M. riyadhense. Ascites caused by M. monacense, pulmonary disease caused by M. riyadhense and M. monacense were rarest clinical events and reported for the first time globally in a pediatric cohort. CONCLUSIONS: Diverse NTM diseases even in immunocompetent children are an upcoming challenge in Saudi Arabia. Lack of awareness on NTM disease must be addressed with immediate development of management plans.

The first Saudi Arabian national inventory study revealed the upcoming challenges of highly diverse non-tuberculous mycobacterial diseases.

BACKGROUND: Incidences of nontuberculous mycobacteria (NTM) causing pulmonary and extrapulmonary diseases are reportedly increasing globally and the current epidemiologic situation in Saudi Arabia remains unclear. To study such trend, we carried out a nationwide systematic epidemiological study focusing on NTM diseases for the first time in the country. METHODS/PRINCIPLE FINDINGS: A nationwide collection of NTM isolates with clinical and demographical data was conducted for a period of 24 months. Primary species identification was carried out by line probe assays followed by sequencing of 16S rRNA, 16S-23S ITS region, rpoB and hsp65 genes. The laboratory findings were comprehensively analysed against demographical and clinical data. A total of 527 isolates were enrolled with a higher proportion of Saudi citizens (76.5%), elderly (>60 years) patients (34.2%), and male gender (65.3%) respectively. Overall, 75.1% isolates were pulmonary origin with a proven clinical significance of 44.7%. In total, 34 NTM species including 17 rare species were identified, in addition to 8 'undefined' isolates. M.simiae (22.6%), M.fortuitum (18.1%) and M.abscessus (17.8%) were predominant species. Interestingly, 27 new cases of clinically relevant M.riyadhense were also noticed (Primary data on emergence of rare NTM species and M.riyadhense has been recently reported). Results showed, rare clinical events such as mycobacteremia, cecum abscess, peritonitis and ascites caused by M.wolinskyi, M.holsaticum, M.duvalii and M.monacence respectively. Diabetes mellitus (P value-0.04) and previous history of tuberculosis (P value- 0.001) were identified as independent risk factors associated with NTM diseases. CONCLUSIONS/SIGNIFICANCE: NTM disease spectrum and pathogen diversity is an emerging challenge to any nation, including Saudi Arabia. Therefore, more priorities will be given to NTM's with an immediate initiative to develop diagnostic infrastructures and disease management plans.

Emergence of Rare Species of Nontuberculous Mycobacteria as Potential Pathogens in Saudi Arabian Clinical Setting.

BACKGROUND: Clinical relevance of nontuberculous mycobacteria (NTM) is increasing worldwide including in Saudi Arabia. A high species diversity of NTM's has been noticed in a recent study. However, the identification in diagnostic laboratories is mostly limited to common species. The impact of NTM species diversity on clinical outcome is so far neglected in most of the clinical settings. METHODOLOGY/PRINCIPAL FINDINGS: During April 2014 to September 2015, a nationwide collection of suspected NTM clinical isolates with clinical and demographical data were carried out. Primary identification was performed by commercial line probe assays. Isolates identified up to Mycobacterium species level by line probe assays only were included and subjected to sequencing of 16S rRNA, rpoB, hsp65 and 16S-23S ITS region genes. The sequence data were subjected to BLAST analysis in GenBank and Ez-Taxon databases. Male Saudi nationals were dominated in the study population and falling majorly into the 46-59 years age group. Pulmonary cases were 59.3% with a surprising clinical relevance of 75% based on American Thoracic Society guidelines. Among the 40.7% extra-pulmonary cases, 50% of them were skin infections. The identification revealed 16 species and all of them are reporting for the first time in Saudi Arabia. The major species obtained were Mycobacterium monascence (18.5%), M. cosmeticum (11.1%), M. kubicae (11.1%), M. duvalli (7.4%), M.terrae (7.4%) and M. triplex (7.4%). This is the first report on clinical relevance of M. kubicae, M. tusciae, M.yongonense, M. arupense and M.iranicum causing pulmonary disease and M. monascence, M. duvalli, M. perigrinum, M. insubricum, M. holsaticum and M. kyorinense causing various extra-pulmonary diseases in Saudi Arabia. Ascites caused by M. monascence and cecum infection by M. holsaticum were the rarest incidents. CONCLUSIONS/SIGNIFICANCE: To the first time in the country, clinical significance of various rare NTM's are well explored and the finding warrants a new threat to the Saudi Arabian clinical settings.

Interferon Gamma Release Assay versus Tuberculin Skin Testing among Healthcare Workers of Highly Diverse Origin in a Moderate Tuberculosis Burden Country.

Health care workers (HCW's) are always at an increased risk of contracting tuberculosis (TB) infection. In Saudi Arabia, Interferon Gamma Release Assay (IGRA) has not been evaluated as a screening tool for latent TB infection (LTBI) among HCW's considering their high demographic diversity. During February 2012 to January 2015 a cross sectional study has been conducted in a tertiary care center with maximum demographically diverse staff population in the capital city-Riyadh. After a short interview and consenting, all the candidates were subjected to tuberculin skin test (TST) and QuantiFERON TB gold In-tube test (QFT). A logistic regression analysis was carried out for establishing the associations between putative risk factors and the diagnostic tests. The candidates were classified according to geographical origin and a detailed analysis was conducted on the impact of their origin towards the results of TST and QFT. Of the 1595 candidates enrolled, 90.6% were BCG vaccinated, female (67.9%) and mainly nurses (53.2%). Candidates with high risk of suspected or confirmed TB patient exposure were 56.1% and 76.5% of them had <10 year's work experience. TST positivity was observed in 503 (31.5%) candidates, while QFT was positive among 399 (25%). Majority of the candidates were non-Saudi (83%) and predominantly (52.4%) from Western Pacific region. Concordant results were obtained in 14.2% of positive cases and 57.7% negative cases. The disagreements between the two tests were relatively high (kappa co-efficient-0.312±0.026, p value- <0.00001) as TST positive/QFT negative discordance was 54.8% while TST negative/QFT positive discordance was 15.7%. Age of the candidates, BCG vaccination, and South East Asian origin were associated with TST positivity while Occupational TB exposure and geographical origin of the candidates were associated with QFT positivity. A regular follow up on recently TST converted candidates showed no progression to active TB. The putative factors associated with the discordance were origin of the candidate (p value <0.001), profession (p value-0.001), BCG vaccination (p value-0.001) and occupational TB exposure level (P value-0.001). The study demonstrated high level prevalence of LTBI among the demographically diverse study candidates. The agreement between QFT and TST was poor, thus QFT alone cannot be recommended in our setting for a routine LTBI screening. Origin of the candidates has strong association with the results of TST and QFT. The discordant results particularly TST negative and QFT positive needs more detailed analysis.

Immediate and long-term results of mitral balloon valvotomy for restenosis following previous surgical or balloon mitral commissurotomy.

This study compared immediate with long-term results of mitral balloon valvotomy (MBV) in patients who underwent MBV as an initial procedure versus those who underwent repeat MBV. Fifty-six patients who were a mean age of 28 +/- 8.8 years (group A) and had mitral restenosis after surgical or balloon commissurotomy underwent MBV and were compared with 524 patients who were a mean age of 31 +/- 11 years (group B) and underwent MBV as an initial procedure. Prospective data obtained included demographic, hemodynamic, echocardiographic, and clinical follow-up for 0.5 to 15 years after MBV. No deaths or technical failure were encountered after MBV. Mitral regurgitation >2/4 occurred in 1 patient (2%) in group A and in 9 patients (2%) in group B (p = 0.24). Fifty-two of 56 patients (93%) in group A had good immediate results (mitral valve area >or=1.5 cm(2), mitral regurgitation <2/4), as did 504 of 524 patients (96%) in group B (p = 0.4). Actuarial values for freedom from restenosis at 10 years were 58 +/- 7% for group A versus 69 +/- 3% for group B (p = 0.18). Ten-year event-free survival rate was 54 +/- 7% for group A versus 80 +/- 3% for group B (p <0.005). The predictors of event-free survival were age (p = 0.003), echocardiographic score (p <0.0001), and baseline atrial fibrillation (p = 0.01). In conclusion, MBV is safe and provides good immediate results in patients who have restenosis. Long-term results are inferior compared with de novo mitral stenosis but is still satisfactory. More than 50% of patients remained improved at 10 years, thus enabling the operation or reoperation to be deferred.

Phase I/II trial of capecitabine, oxaliplatin, and irinotecan in combination with bevacizumab in first line treatment of metastatic colorectal cancer.

Phase III studies have demonstrated the efficacy of FOLFOXIRI regimens (5-fluorouracil/leucovorin, oxaliplatin, irinotecan) with/without bevacizumab in metastatic colorectal cancer (mCRC). Capecitabine is an orally administered fluoropyrimidine that may be used instead of 5-fluorouracil/leucovorin. We evaluated a triple-chemotherapy regimen of capecitabine, oxaliplatin, and irinotecan, plus bevacizumab in 53 patients with mCRC. A Phase I study identified the maximum tolerated dose of irinotecan as 150 mg/m². Median follow-up in a subsequent Phase II study using this dose was 28 months (74% progressed). For all patients, a complete response was achieved in 4% and a partial response in 60%; median progression-free survival (PFS) was 16 months and median overall survival (OS) was 28 months. Median PFS was longer for patients with an early treatment response (28 vs. 9 months for others; P = 0.024), or early tumor shrinkage (25 vs. 9 months for others; P = 0.006), or for patients suitable for surgical removal of metastases with curative intent (median not reached vs. 9 months for others; P = 0.001). Median OS was longer for patients with early tumor shrinkage (median not reached vs. 22 months for others; P = 0.006) or surgery (median not reached vs. 22 months for others, P = 0.002). K-ras mutations status did not influence PFS (P = 0.88) or OS (P = 0.82). Considerable Grade 3/4 toxicity was encountered (36% for diarrhea, 21% for vomiting and 17% for fatigue). In conclusion, the 3-weekly triple-chemotherapy regimen of capecitabine, oxaliplatin, and irinotecan, plus bevacizumab, was active in the first-line treatment of mCRC, although at the expense of a high level of toxicity.

Exploring the sociodemographic and clinical features of extrapulmonary tuberculosis in Saudi Arabia.

BACKGROUND: Saudi Arabia annually reports a relatively higher proportion (28-32%) of extrapulmonary tuberculosis (EPTB) cases in comparison to other global regions. However, there were few studies conducted so far to determine the sociodemographic factors and clinical manifestations associated with EPTB at a nationwide level. METHODOLOGY: A retrospective analysis on culture positive EPTB isolates collected from all the provinces of the country were conducted for a period of 12 months to determine the spectrum of diversity in EPTB infection sites and the confounding factors. A detailed clinical and demographical data analysis was carried out along with first line drug susceptibility testing. PRINCIPAL FINDINGS: Intra-thoracic and extra-thoracic lymph nodes (44.6%) were the most common sites of infection followed by gastrointestinal (17.3%) and central nervous systems (11.8%). Male patients were mostly infected (58.8%), in contrary to the global trend. Any drug resistance was observed in 23.1% isolates with a 2.1% of multi-drug resistance. HIV reactivity was found only in 2.2% cases. A higher proportion of Saudi nationals (58.8%) were infected compared to the immigrants, descending mostly from South Asia (34.4%) and South East Asia (31.2%). The Saudi population predominated with all forms of EPTB while immigrants showed no significant variations. CONCLUSIONS: Saudi Arabia faces a serious threat from EPTB, particularly to the central nervous system and gastrointestinal systems. More effective diagnostic strategies and control measures must be implemented to reduce the high rate of EPTB in the country. In addition, these findings warrant further detailed research to explore all related comorbid conditions of EPTB development, particularly the host-related factors.

Progression of matrixin and cardiokine expression patterns in an ovine model of heart failure and recovery.

BACKGROUND: The molecular mechanisms underlying the geometrical changes of the left ventricle during the progression to heart failure and recovery are not well defined. OBJECTIVE: Here we investigate the involvement of matrixins and cardiokines in an ovine model of pressure-induced left ventricular failure (LVF). METHODS: Fifteen sheep underwent supracoronary aortic banding with an inflatable cuff. A controlled and progressive increase of LV pressure was monitored echocardiographically. Endomyocardial biopsies were collected throughout the development of LVF and subsequent recovery after pressure unloading. RESULTS: Thirteen sheep developed LVF with a subsequent recovery. Peak left ventricular hypertrophy (LVH) and dilatation (LVD) occurred at 31.5 ± 1.6 weeks and 102.7 ± 2.2 weeks post-banding respectively, with an increase in LV internal diameter in diastole (LVIDd 5.11 ± 0.12 compared to the control 3.37 ± 0.07 cm, p<0.001), with preserved LV ejection fraction (LVEF). Reduced LVEF became evident 116.5 ± 2.7 weeks post-banding. Clinical and echocardiographic improvements were observed following deflation of the aortic banding cuff. By 138.1 ± 3.1 weeks cardiac performance recovered with restoration of LVEF. Significant changes in the expression of matrix metalloproteinases (MMP)-1, -2, -3, vascular endothelial cell growth factor (VEGF), fibroblast growth factor (FGF)-2, interferon (INF)-α-2 and soluble CD40 ligand (sCD40L) were observed throughout the progression to failure and recovery. CONCLUSIONS: We used an ovine model to study reversible LV remodelling without interruption and found significant changes in matrixin and cardiokine expression during LV progression to failure and recovery.

Occurrence of diverse mutations in isoniazid- and rifampicin-resistant Mycobacterium tuberculosis isolates from autochthonous and immigrant populations of Saudi Arabia.

For the first time in Saudi Arabia, the impact of a patient's ethnic background on mutations conferring resistance to rifampicin (RIF) and isoniazid (INH) in Mycobacterium tuberculosis isolates was analyzed on a nationwide sample collection. Four hundred fifteen isolates were subjected to drug susceptibility testing, mutation analysis, spoligotyping, and 24 loci-based Mycobacterial Interspersed Repetitive Units-Variable Number Tandem Repeat typing, respectively. Phenotypically, 41 (9.9%) isolates were resistant to RIF, 239 (57.6%) to INH, and 135 (32.5%) to both RIF and INH, respectively. Forty (9.6%), 236 (56.8%), and 133 (32%) isolates were determined as resistant to RIF, INH, and to both by molecular assay. Codon 531 (S531L) mutations (69.4%) in the rpoB gene and codon 315 (S315T) mutations (67.2%) in the katG gene were the most prominent among RIF- and INH-resistant isolates, respectively. The autochthonous population showed a predominance of rpoB codon 516 and 526 mutations, while the inhA promoter position -15 and -8 mutations were prominent among immigrants. A strain cluster ratio of 32% (30 clusters) was observed and 24 clusters displayed identical mutations. Overall, Euro-American lineages were predominant. However, Beijing (56.7%) and EAI (42.7%) were noticed with the highest cluster rate. In Saudi Arabia, the occurrence of mutations responsible for INH and RIF resistance was significantly associated with the ethnic origin of the patient.

Admixed phylogenetic distribution of drug resistant Mycobacterium tuberculosis in Saudi Arabia.

BACKGROUND: The phylogeographical structure of Mycobacterium tuberculosis is generally bimodal in low tuberculosis (TB) incidence countries, where genetic lineages of the isolates generally differ with little strain clustering between autochthonous and foreign-born TB patients. However, less is known on this structure in Saudi Arabia-the most important hub of human migration as it hosts a total population of expatriates and pilgrims from all over the world which is equal to that of its citizens. METHODOLOGY: We explored the mycobacterial phylogenetic structure and strain molecular clustering in Saudi Arabia by genotyping 322 drug-resistant clinical isolates collected over a 12-month period in a national drug surveillance survey, using 24 locus-based MIRU-VNTR typing and spoligotyping. PRINCIPAL FINDINGS: In contrast to the cosmopolitan population of the country, almost all the known phylogeographic lineages of M. tuberculosis complex (with noticeable exception of Mycobacterium africanum/West-African 1 and 2) were detected, with Delhi/CAS (21.1%), EAI (11.2%), Beijing (11.2%) and main branches of the Euro-American super-lineage such as Ghana (14.9%), Haarlem (10.6%) and Cameroon (7.8%) being represented. Statistically significant associations of strain lineages were observed with poly-drug resistance and multi drug resistance especially among previously treated cases (p value of < = 0.001 for both types of resistance), with relative over-representation of Beijing strains in the latter category. However, there was no significant difference among Saudi and non-Saudi TB patients regarding distribution of phylogenetic lineages (p = 0.311). Moreover, 59.5% (22/37) of the strain molecular clusters were shared between the Saudi born and immigrant TB patients. CONCLUSIONS: Specific distribution of M. tuberculosis phylogeographic lineages is not observed between the autochthonous and foreign-born populations. These observations might reflect both socially favored ongoing TB transmission between the two population groups, and historically deep-rooted, prolonged contacts and trade relations of the peninsula with other world regions. More vigorous surveillance and strict adherence to tuberculosis control policies are urgently needed in the country.

Current trends of Mycobacterium tuberculosis molecular epidemiology in Saudi Arabia and associated demographical factors.

Data are scarce on demographical factors related to the population structure of Mycobacterium tuberculosis in Saudi Arabia. A study was conducted on 902 clinical isolates to explore current trends in the phylogeography and associated demographical factors of tuberculosis by using spoligotyping and 24 loci based MIRU-VNTR typing. Young male patients (aged 16-29 and 30-44) were predominant in this cohort. The phylogenetic diversity among M. tuberculosis isolates was found high, as almost all known genetic lineages were identified. Delhi/CAS (26.4%), EAI (13.7%) and Haarlem (11.3%) were the most common lineages observed, particularly among the low age groups (16-29 and 30-44 years), whereas elderly patients (>60 years) showed a predominance in the lineages S, Ghana, TUR and Uganda-I. A statistically significant association was observed between gender of the patients and lineages of EAI (p value 0.026) and LAM (p value 0.005). Overall, molecular strain cluster rate was 34.4% with an elevated rate among patients aged below 15 years (43.1%), while cases among the elderly (>60 years) showed the lowest degree of clustering (12.5%). The largest level of clustering was noticed among cases caused by strains of the lineages Haarlem (59.8%), Beijing (55.8%) and LAM (42.8%). The current population structure of M. tuberculosis in Saudi Arabia is highly diverse with significant associations to demography, transmission dynamics and origin of the patients. The difference in genotype distributions among low and high aged patients reflects the ongoing change in the strain population structure in the country.

Tuberculosis transmission among immigrants and autochthonous populations of the eastern province of Saudi Arabia.

BACKGROUND: Eastern province of Saudi Arabia is an industrial zone with large immigrant population and high level of tuberculosis case notification among immigrants. The impact of immigration and current trends of tuberculosis transmission among immigrants and autochthonous population in the region had not been investigated so far using molecular tools. METHODOLOGY: During 2009- 2011, a total of 524 Mycobacterium tuberculosis isolates were collected from the central tuberculosis reference laboratory, representing an estimated 79.2% of the culture-positive tuberculosis cases over the study period in the province. These isolates were genotyped by using 24 locus-based MIRU-VNTR typing and spoligotyping followed by first line drug susceptibility testing. The molecular clustering profiles and phylogenetic diversity of isolates were determined and compared to the geographical origins of the patients. PRINCIPLE FINDINGS: Genotyping showed an overall predominance of Delhi/CAS (29.4%), EAI (23.8%) and Ghana (13.3%) lineages, with slightly higher proportions of Delhi/CAS among autochthonous population (33.3 %) and EAI (30.9%) among immigrants. Rate of any drug resistance was 20.2% with 2.5% of multi-drug resistance. Strain cluster analysis indicated 42 clusters comprising 210 isolates, resulting in a calculated recent transmission index of 32.1%. Overall shared cluster ratio was 78.6% while 75.8% were shared between autochthonous population and immigrant population with a predominance of immigrants from South east Asia (40.7%). In contrast, cross national transmission within the immigrant population was limited (24.2%). Younger age (15-30- p value-0.043, 16-45, p value 0.030), Saudi nationality (p value-0.004) and South East Asian origin (p value-0.011) were identified as significant predisposing factors for molecular strain clustering. CONCLUSIONS: The high proportion of molecular clusters shared among the autochthonous and immigrant populations suggests a high permeability of tuberculosis transmission between both populations in the province. These results prompt for the need to strengthen the current tuberculosis control strategies and surveillance programs.

New insight into the molecular characterization of isoniazid and rifampicin resistant Mycobacterium tuberculosis strains from Saudi Arabia.

Data on the genetic variation of isolates of Mycobacterium tuberculosis and spectrum of mutations determining resistance to principal anti-tuberculosis drugs isoniazid (INH) and rifampicin (RIF) have not yet been studied in Saudi Arabia. One hundred and fifty-one clinical isolates of M. tuberculosis from different regions in the country showing resistance to RIF and INH were subjected to drug susceptibility testing, characterization of mutations conferring drug resistance and genotyping. Phenotypically 17 (11.3%) isolates were resistance to RIF, 75 (49.6%) were resistant to INH and 59 (39.1%) were resistant to both RIF and INH, respectively. Sixteen (10.6%), 74 (49%) and 56 (37.1%) were determined as resistant to RIF, INH and to both by line probe assay. High frequency of rpoB 531 mutations (67.1%) in RIF resistant strains and katG 315 mutations (65.2%) in INH resistant strains were found. Mutations responsible for INH resistance, katG 315 (P value<0.001, odds ratio: 1.81, 95% CI [1.51, 2.18]) and inhA-15 (P value - 0.004, odds ratio: 1.48, 95% CI [1.22, 1.8]) were predominant among the newly diagnosed cases. Beijing strains were significantly associated with multi drug resistance and mutations in combination of rpoB531 and katG315 (P value - <0.001, odds ratio: 6.83, 95% CI [2.65, 17.58]). In addition multi drug resistance was significantly associated with treatment history (P value<0.001, odds ratio: 3.16, 95% CI [2.14, 4.67]). Furthermore, a higher rate (39.3%) of clustering among the multidrug resistant strains particularly with Beijing family (52.9%) was observed. Saudi Arabia harbors highly diverse drug resistant M. tuberculosis population with an ongoing transmission which needs to be immediately managed.