The biofilm formation and antibiotic resistance of bacterial profile from endotracheal tube of patients admitted to intensive care unit in southwest of Iran.

Ventilator-associated pneumonia (VAP) is a prevalent nosocomial illness in mechanically ventilated patients. Hence, the aim of this study was to investigate the pattern of antibiotic resistance and biofilm formation of bacterial profiles from Endotracheal Tubes of patients hospitalized in an intensive care unit in southwest Iran. According to the standard operating method, the microbiological laboratory conducts bacteria culture and susceptibility testing on endotracheal Tube samples suspected of carrying a bacterial infection. The Clinical and laboratory standards institute (CLSI) techniques are used to determine the Antimicrobial resistance (AMR) of bacterial isolates to antibiotics using the disk diffusion method. The crystal violet staining method was used to assess the biofilm-forming potential of isolates in a 96-well microtiter plate. In total, (51%) GPBs were included in this study. The isolated GPB were coagulase-negative Staphylococcus (16%), S. aureus (14%). In total, (40%) of GNB were included in this study. The isolated GNB were Klebsiella spp. (36%), A. baumannii (22%), P. aeruginosa (35%). (32%) bacterial strains were MDR and (29%) strains were XDR. The results of biofilm formation showed (72%) were biofilm producers. VAP is a common and severe nosocomial infection in mechanically ventilated patients. Controlling biofilm formation, whether on the ET or in the oropharyngeal cavity, is thus an important technique for treating VAP. Colistin and linezolid are antibiotics that are effective against practically all resistant GNB and GPB isolates.

Genetic diversity of drug-resistant Mycobacterium tuberculosis clinical isolates from Khuzestan province, Iran.

The emergence of drug-resistant strains of the Mycobacterium tuberculosis (MTB) has challenged tuberculosis control programs. So far, few studies using the 24-locus mycobacterial interspersed repetitive unit variable number tandem repeats (MIRU-VNTR) have investigated the genetic diversity of MTB in Iran. This study aimed to determine the genetic diversity of MTB isolates resistant to first-line anti-tuberculosis drugs using 24-locus MIRU-VNTR in southwestern Iran. Out of 6620 MTB clinical isolates, 29 resistant isolates to one or more isoniazid, rifampin, and ethambutol were detected using drug susceptibility testing by the proportional method. The manual 24-locus MIRU-VNTR was used to determine the MTB resistant isolates' phylogenetic relationship. MIRU-VNTRplus web application tools were applied to analyze the associated data. Using 24-locus MIRU-VNTR, 13.8% of isolates (n = 4) were distributed in two clusters, and the remaining 86.2% (n = 25) showed a unique pattern. Four clonal complexes were observed in the minimum spanning tree based on the double-locus variant. Most isolates belonged to Delhi/CAS (34.5%, 10/29) and NEW-1 (24.1%, 7/29) sub-lineages, followed by EAI and LAM with a frequency of 6.9% (2/29) and 3.5% (1/29), respectively. Eight isolates (27.6%) did not match any genotype in the database. The 24-locus MIRU-VNTR showed a high discriminatory power; however, the 15-locus and 12-locus set analyses were more discriminative. Our study revealed a high degree of genetic diversity among drug-resistant MTB isolates, which could be interpreted as the low rate of person-to-person transmission in this region. The 15-locus MIRU-VNTR would be recommended for preliminary genotyping of drug-resistant MTB.

Identification of mutations in rpoB, pncA, embB, and ubiA genes among drug-resistant Mycobacterium tuberculosis clinical isolates from Iran.

Mycobacterium tuberculosis resistant to effective first-line drugs (FLDs) has challenged national and global tuberculosis control programs. This study aimed to identify mutations in 4 genes related to rifampin, pyrazinamide, and ethambutol resistance among clinical isolates of M. tuberculosis from southwestern Iran. After drug susceptibility testing of 6620 M. tuberculosis clinical isolates by proportional method, a total of 24 FLD-resistant strains were included in the study. Fragments of rpoB, pncA, embB, and ubiA genes were amplified and sequenced to mine the mutations by pairwise alignment with the corresponding M. tuberculosis H37Rv genes. Phenotypic resistance to rifampin, isoniazid, and ethambutol was detected in 67, 54, and 33% (n = 16, 13, and 8) of the isolates, respectively. Of rifampin-resistant isolates, 31% (5/16) were mono-resistant, and 56% (9/16) were multidrug-resistant (MDR). In 100% of rifampin-resistant isolates, mutations were found in the rifampin resistance-determining region (RRDR) of the rpoB, with S450L substitution being the most common, especially in MDRs (77.8%, 7/9). Resistance-conferring mutations in pncA were present in 12.5% (3/24) of FLD-resistant isolates. The embB and ubiA mutations were found in 62.5 and 12.5% (5/8 and 1/8) of ethambutol-resistant isolates, respectively, of which the embB D354A was the most common substitution (37.5%, 3/8). Sixteen distinct mutations were identified, one of which was novel. The sequence analysis of the RRDR segment was the best way to detect rifampin resistance. The rpoB S450L substitution could be a helpful molecular marker to predict MDR. In other genes, no mutation was identified as a reliable marker.

Detection and characterization of mutations in genes related to isoniazid resistance in Mycobacterium tuberculosis clinical isolates from Iran.

BACKGROUND: The global rise in drug-resistant Mycobacterium tuberculosis (M.tb), and especially the significant prevalence of isoniazid (INH)-resistance constitute a significant challenge to global health. Therefore, the present study aimed to investigate mutations in prevalent gene loci-involved in INH-resistance phenotype-among M.tb clinical isolates from southwestern Iran. METHODS: Drug susceptibility testing (DST) was performed using the conventional proportional method on confirmed 6620 M.tb clinical isolates, and in total, 15 INH-resistant and 18 INH-susceptible isolates were included in the study. Fragments of six genetic loci most related to INH-resistance (katG, inhA promoter, furA, kasA, ndh, oxyR-ahpC intergenic region) were PCR-amplified and sequenced. Mutations were explored by pairwise alignment with the M.tb H37Rv genome. RESULTS: The analysis of gene loci revealed 13 distinct mutations in INH-resistant isolates. 60% (n = 9) of the INH-resistant isolates had mutations in katG, with codon 315 predominately (53.3%, n = 8). Mutation at InhA - 15 was found in 20% (n = 3) of resistant isolates. 26.7% (n = 4) of the INH-resistant isolates had kasA mutations, of which G269S substitution was the most common (20%, n = 3). The percentage of mutations in furA, oxyR-ahpC and ndh was 6.7% (n = 1), 46.7% (n = 7), and 20% (n = 3), respectively. Of the mutations detected in ndh and oxyR-ahpC, 5 were also observed in INH-susceptible isolates. This study revealed seven novel mutations, four of which were exclusively in resistant isolates. CONCLUSIONS: This study supports the usefulness of katG and inhA mutations as a predictive molecular marker for INH resistance. Co-detection of katG S315 and inhA-15 mutations identified 73.3% (11 out of 15 isolates) of INH-resistant isolates.

Occurrence of Multiple-Drug Resistance Bacteria and Their Antimicrobial Resistance Patterns in Burn Infections from Southwest of Iran.

Burn infection continues to be a major issue of concern globally and causes more harm to developing countries. This study aimed to identify the aerobic bacteriological profiles and antimicrobial resistance patterns of burn infections in three hospitals in Abadan, southwest Iran. The cultures of various clinical samples obtained from 325 burn patients were investigated from January to December 2019. All bacterial isolates were identified based on the standard microbiological procedures. Antibiotic susceptibility tests were performed according to the CLSI. A total of 287 bacterial species were isolated from burn patients. Pseudomonas aeruginosa was the most frequent bacterial isolate in Gram-negative bacteria and S. epidermidis was the most frequent species isolated in Gram-positive bacteria. The maximum resistance was found to ampicillin, gentamicin, ciprofloxacin, while in Gram-negative bacteria, the maximum resistance was found to imipenem, gentamicin, ciprofloxacin, ceftazidime, and amikacin. The occurrence of multidrug resistance phenotype was as follows: P. aeruginosa (30.3%), Enterobacter spp (11.1%), Escherichia coli (10.5%), Citrobacter spp (2.1%), S. epidermidis (2.8%), S. aureus, and S. saprophyticus (0.7%). Owing to the diverse range of bacteria that cause burn wound infection, regular investigation, and diagnosis of common bacteria and their resistance patterns is recommended to determine the proper antibiotic regimen for appropriate therapy.

Prevalence and treatment outcome of pulmonary and extrapulmonary pediatric tuberculosis in southwestern Iran.

BACKGROUND: Knowledge about childhood tuberculosis (TB) in Iran is limited. This study aimed to determine the proportion of tuberculosis in children living in Khuzestan in southwest of Iran and its treatment outcomes. METHODS: In this retrospective study, the child's medical records registered in national TB program (NTP) unit of Khuzestan Health Center (KHC) for TB treatment from 2005 to 2010 were studied. Data including demographic, clinical presentation, laboratory test results, and treatment outcomes were extracted from the files and were analyzed. RESULTS: Of total 4104 new TB cases registered in KHC, 203 (4.9%) were children. The mean age was 10.7±4.3 years, and 75.7% of them were females. More than 84% of TB children cases were 10 years or older, whereas, young children (< 5 years old) accounted for 5.6%. Of the total studied cases, 57.1% were pulmonary TB and 42.9% were extra pulmonary, 91.7% were successfully treated and 8.3% had poor treatment outcome. The main risk factors for poor treatment outcome were: age <5 years (OR: 0.17, 95% CI, 0.04-0.76), low body weight (OR: 0.08, 95% CI, 0.01-0.60), household contact with cases of TB treatment failure (OR: 0.13, 95% CI, 0.03-0.52), and exposure to cigarette smoke odor inside the home (OR: 0.17, 95% CI, 0.05-0.56). CONCLUSION: The proportion of pediatric TB in the region was lower than expected. The treatment success rate was higher than the rate defined in NTP. Special attention should be given to children aged less than five years, low body weight, contact with TB treatment failure cases, and exposure to cigarette smoke.

Factors associated with delay in diagnosis and treatment of pulmonary tuberculosis.

BACKGROUND: Early treatment of pulmonary tuberculosis (PTB) is necessary for a successful tuberculosis (TB) control program. OBJECTIVES: The objective of this study was to determine total treatment delay and its associated factors among PTB patients in Ahvaz. PATIENTS AND METHODS: A retrospective study was performed among newly diagnosed PTB cases registered in 2010 at the Ahvaz health center. Total treatment delay was defined as the time interval between the onsets of cough to the initiation of anti-TB treatment. Tuberculosis diagnosis and treatment was based on the national TB program (NTP). Data analysis was performed using the SPSS software by chi-square and Fisher's exact test with odds ratio (OR) and 95% confidence interval (CI). RESULTS: The mean age of the patients was 38.9 ± 12.3 years; 83 were male and 56 were female. Of the 139 smear positive PTB cases, 91 (65.5%) cases had received delayed-treatment. The mean time between onset of symptoms, diagnosis and treatment was 73 days (median: 48 days, range: 4-570 days). Female gender (OR (95% CI): 2.9, 1.03-8.23, P = 0.02), smoking (OR (95% CI): 0.49, 0.22-0.96, P = 0.04) and receiving immunosuppressive drugs (OR (95% CI): 8.18, 1.09-75.31, P < 0.05) were associated with longer delayed time. CONCLUSIONS: Delayed diagnosis and treatment of tuberculosis appears to be the main problem in the TB control program of the region. Delayed time is significantly associated with female gender, smoking and immunosuppressive drugs.

Prevalence of pulmonary tuberculosis before and after soil dust in Khuzestan, southwest Iran.

BACKGROUND: Soil dust has been debated about its effects on public health and the challenge is brought about tuberculosis (TB). The purpose of this study was to investigate the influence of soil dust on pulmonary tuberculosis (PTB) prevalence and its control indices. METHODS: The medical files of patients in Khuzestan Health Center were reviewed. The control group included the PTB patients registered from 2005 to 2006 (before soil dust), and case group consisted of PTB patients who were registered from 2007 to 2010 (after soil dust exposure). The diagnosis of tuberculosis was based on National Tuberculosis Program (NTP). RESULTS: The mean age of control and case group was 42 (18-80) years and 40 (13-99) years, respectively. The prevalence of pulmonary TB in the control and case group was 537 (12.5 per 100000 population) and 465 (11.0 per 100000 population), respectively. Exposure to dust did not increase the prevalence of TB. The prevalence was higher in women than men (298, 41.8% vs. 336, 48.2%), in children than adult group (31, 4.3% vs. 53, 7.3%), in urban than rural inhabitants (448, 63% vs.496, 71.1%) and in family contacts than solitary contamination (60, 8.4% vs. 97, 13.9%). The rate of treatment failure, TB relapse, and MDR-TB in controls and cases were (1.4%, 1.4%, 1%) and (7%, 5.5%, 4.6%), respectively. Dust exposure had significant effect on treatment outcome. CONCLUSION: Although soil dust exposure had no significant effect on TB prevalence, but significantly affected the prevalence of TB respecting to age, sex, residential area and closed contact. In addition resulted in more treatment failure, development of MDR TB and relapse.