Isolation, molecular characterization and growth-promotion activities of a cold tolerant bacterium Pseudomonas sp. NARs9 (MTCC9002) from the Indian Himalayas.

A bacterium that grows and expresses plant growth promotion traits at 4 degrees C was isolated from the rhizospheric soil of Amaranth, cultivated at a high altitude location in the North Western Indian Himalayas. The isolate was Gram negative and the cells appeared as rods (2.91 x 0.71 microm in size). It grew at temperatures ranging from 4 to 30 degrees C, with a growth optimum at 28 degrees C. It exhibited tolerance to a wide pH range (5-10; optimum 8.0) and salt concentrations up to 6% (wt/vol). Although it was sensitive to Rifampicin (R 20 microg mi-1), Gentamicin (G 3 microg mi-1), and Streptomycin (S 5 microg mi-1), it showed resistance to higher concentrations of Ampicillin (A 500 microg mi-1), Penicillin (P 300 microg mi-1), Polymixin B sulphate (Pb 100 microg mi-1) and Chloramphenicol (C 200 microg mi-1). The 16S rRNA sequence analysis revealed maximum identity with Pseudomonas lurida. The bacterium produced indole Acetic Acid (IAA) and solubilizes phosphate at 4, 15 and 28 degrees C. It also retained its ability to produce rhamnolipids and siderophores at 15 degrees C. Seed bacterization with the isolate enhanced the germination, shoot and root lengths of thirty-day-old wheat seedlings by 19.2, 30.0 & 22.9% respectively, as compared to the un-inoculated controls.

Quorum sensing pathways in Gram-positive and -negative bacteria: potential of their interruption in abating drug resistance.

Quorum sensing (QS) is an inter-cell communication between bacterial populations through release of tiny diffusible compounds as signalling agents, called auto-inducers, abetting bacteria to track population density. QS allows bacterial population to perform collectively in coordination to wide phenotypes like alterations in expression of virulence genes to achieve advancement over their competitors, drug resistance and biofilm formation. Several classes of autoinducers have been described that are involved in bacterial virulence. This review gives an insight into the multitudinous QS systems in Gram-positive and Gram-negative bacteria to explore their role in microbial physiology and pathogenesis. Bacterial resistance to antibiotics has clinically become a super challenge. Strategies to interrupt QS pathways by natural and synthetic QS inhibitors or quorum quenchers or analogs provide a potential treatment. We highlight the advancements in discovery of promising new targets for development of next generation antimicrobials to control infections caused by multidrug resistant bacterial pathogens.

Video-assisted thoracoscopic decortication for the management of late stage pleural empyema, is it feasible?

BACKGROUND: Video-assisted thoracoscopic surgical decortication (VATSD) is widely applicable in fibrinopurulent Stage II empyema. While, more chronic thick walled Stage III empyema (organizing stage) needs conversion to open thoracotomy, and existing reports reveal a lacuna in the realm of late stage empyema patient's management through VATS utilization, particularly Stage III empyema. We prospectively evaluated the application of VATSD regardless of the stage of pleural empyema for the effective management of late stage empyema in comparison to open decortications (ODs) to minimize the adverse effects of the disease. METHODS: All patients with pyogenic pleural empyema (Stage II and Stage III) in King Khalid University Hospital (KKUH) (admitted from January 2009 to December 2013) who did not respond to chest tube/pigtail drainage and/or antibiotic therapy were treated with VATSD and/or open thoracotomy. Prospective evaluation was carried out, and the effect of this technique on perioperative outcomes was appraised to evaluate our technical learning with the passage of time and experience with VATS for late stage empyema management. RESULTS: Out of total 63 patients, 26 had Stage II empyema and 37 had Stage III empyema. VATSD was employed on all empyema patients admitted in the KKUH. VATSD was successful in all patients with Stage II empyema. Twenty-five patients (67.6%) with Stage III empyema completed VATSD successfully. However, only 12 cases (32.4%) required conversions to open (thoracotomy) drainage (OD). The median hospital stay for Stage III VATSD required 9.65 ± 4.1 days. Whereas, patients who underwent open thoracotomy took longer time (21.82 ± 16.35 days). Similarly, Stage III VATSD and Stage III open surgery cases showed significance difference among chest tube duration (7.84 ± 3.33 days for VATS and 15.92 ± 8.2 days for open thoracotomy). Significantly, lower postoperative complications were detected in patients treated with VATSD in terms of atelectasis, prolonged air leak, wound infection, etc. CONCLUSION: VATSD facilitates the management of fibrinopurulent, organized pyogenic pleural empyema with less postoperative discomfort, reduced hospitalization, and have fewer postoperative complications. VATSD can be an effective, safe first option for patients with Stage II pleural empyema, and feasible in most patients with Stage III pleural empyema.

CD14 -159 C>T gene polymorphism with increased risk of tuberculosis: evidence from a meta-analysis.

Cluster of differentiation 14 (CD14) gene is an important component of the human innate immune system and its role in tuberculosis (TB) has been sparsely documented. The enhanced plasma CD14 levels in TB patients as compared to healthy controls are associated with CD14 gene promoter (C-159T) polymorphism. In the past few years, the relationship between CD14 -159 C>T (rs2569190) polymorphism and risk of TB has been reported in various ethnic populations; however, those studies have yielded contradictory results. In this study systemic assessment was done for the published studies based on the association between CD14 -159 C>T polymorphism and TB risk retrieved from PubMed (Medline) and EMBASE search. A total number of 1389 TB cases and 1421 controls were included in this study and meta-analysis was performed to elucidate the association between CD14 -159 C>T polymorphism and its susceptibility towards TB. Pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated for allele contrast, homozygous comparison, heterozygous comparison, dominant and recessive genetic model. It was found that T allele carrier was significantly associated with increased TB risk (T vs. C: p-value = 0.023; OR = 1.305, 95% CI = 1.038 to 1.640). Similarly, homozygous mutant TT genotype also revealed 1.6 fold increased risk of TB (TT vs. CC; p-value = 0.040; OR = 1.652, 95% CI = 1.023 to 2.667). Additionally, dominant genetic model demonstrated increased risk of developing TB (TT vs. CC+CT: p-value = 0.006; OR = 1.585, 95% CI = 1.142 to 2.201). The study demonstrates that CD14 gene (-159 C>T) polymorphism contributes increased susceptibility for TB. Moreover, this meta-analysis also suggests for future larger studies with stratified case control population and biological characterization for validation studies.

Isolation, molecular characterization and growth-promotion activities of a cold tolerant bacterium Pseudomonas sp. NARs9 (MTCC9002) from the Indian Himalayas

A bacterium that grows and expresses plant growth promotion traits at 4°C was isolated from the rhizospheric soil of Amaranth, cultivated at a high altitude location in the North Western Indian Himalayas. The isolate was Gram negative and the cells appeared as rods (2.91 x 0.71 μm in size). It grew at temperatures ranging from 4 to 30°C, with a growth optimum at 28°C. It exhibited tolerance to a wide pH range (5-10; optimum 8.0) and salt concentrations up to 6 percent (wt/vol). Although it was sensitive to Rifampicin (R 20 μg mi-1), Gentamicin (G 3 μg mi-1), and Streptomycin (S 5 μg mi-1), it showed resistance to higher concentrations of Ampicillin (A 500 μg mi-1), Penicillin (P 300 μg mi-1), Polymixin B sulphate (Pb 100 μg mi-1) and Chloramphenicol (C 200 μg mi-1). The 16S rRNA sequence analysis revealed maximum identity with Pseudomonas lurida. The bacterium produced indole Acetic Acid (IAA) and solubilizes phosphate at 4, 15 and 28°C. It also retained its ability to produce rhamnolipids and siderophores at 15°C. Seed bacterization with the isolate enhanced the germination, shoot and root lengths of thirty-day-old wheat seedlings by 19.2, 30.0 & 22.9 percent respectively, as compared to the un-inoculated controls.