A comparative study of coastal and clinical isolates of Pseudomonas aeruginosa

Pseudomonas aeruginosa is a ubiquitous Gram-negative bacterium having a versatile metabolic potential and great ecological and clinical significance. The geographical distribution of P. aeruginosahas revealed the existence of an unbiased genetic arrangement in terrestrial isolates. In contrast, there are very few reports about P. aeruginosa strains from marine environments. The present work was aimed at studying the distribution of P. aeruginosa in coastal waters along the Indian Peninsula and understanding the environmental influence on genotypic, metabolic and phenotypic characteristics by comparing marine and clinical isolates. Of the 785 marine isolates obtained on selective media, only 32 (~4.1%) were identified as P. aeruginosa, based on their fatty acid methyl ester profiles. A low Euclidian distance value (< 2.5) obtained from chemotaxonomic analysis suggested that all the environmental (coastal and marine) isolates originated from a single species. While UPGMA analyses of AP-PCR and phenotypic profiles separated the environmental and clinical isolates, fatty acid biotyping showed overlapping between most clinical and environmental isolates. Our study revealed the genetic diversity among different environmental isolates of P. aeruginosa. While biogeographical separation was not evident based solely on phenotypic and metabolic typing, genomic and metatranscriptomic studies are more likely to show differences between these isolates. Thus, newer and more insightful methods are required to understand the ecological distribution of this complex group of bacteria.

Closed reduction and percutaneous pinning of displaced supracondylar fractures of humerus in children with delayed presentation / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>Supracondylar fractures of the humerus account for 60% of all the fractures around the pediatric elbow and even in developed countries 18% of patients undergo surgery 48 hours or longer following presentation in the hospital. Management guidelines are not clear yet for these patients who present late. The aim of this prospective study was to evaluate the clinical, radiological and functional outcome following closed reduction and percutaneous pinning of widely displaced supracondylar fractures of the humerus presenting 12 hours or more after injury.</p><p><b>METHODS</b>We reviewed the functional and radiological results of closed reduction and percutaneous pinning using crossed K-wires in 40 patients with displaced extension type supracondylar fracture of the humerus (Gartland type III) with a delay of more than 12 hours in presentation. The average age of patients was 4.5 years and the mean delay in presentation was 17.55 hours.</p><p><b>RESULTS</b>Closed reduction and percutaneous pinning was successful in 90% of patients. The mean follow up period was 15 months. The Baumann's angle was restored within 4 degrees of the unaffected side in all patients. Use of a small medial incision in patients with severe swelling helped us avoid ulnar nerve injury. Using Flynn's criteria, 38 patients (95%) had an excellent result. Two patients had mild myositis and both had a poor result. None of the patients developed cubitus varus.</p><p><b>CONCLUSION</b>Closed reduction and crossed pinning of displaced supracondylar fractures of humerus in children is a safe and effective method even with delayed presentation.</p>

Biochemical and molecular characterization of Bacillus pumilus isolated from coastal environment in Cochin, India / Caracterização bioquímica e molecular de Bacillus pumilus isolado do ambiente costeiro de Cochin, Índia

Bacillus species constitute a diverse group of bacteria widely distributed in soil and the aquatic environment. In this study, Bacillus strains isolated from the coastal environment of Cochin, India were identified by detailed conventional biochemical methods, fatty acid methyl ester (FAME) analysis and partial 16S rDNA sequencing. Analysis of the data revealed that Bacillus pumilus was the most predominant species in the region under study followed by B. cereus and B. sphaericus. The B. pumilus isolates were further characterized by arbitrarily primed PCR (AP-PCR), antibiotic sensitivity profiling and PCR screening for known toxin genes associated with Bacillus spp. All B. pumilus isolates were biochemically identical, exhibited high protease and lipase activity and uniformly sensitive to antibiotics tested in this study. One strain of B. pumilus harboured cereulide synthetase gene cesB of B. cereus which was indistinguishable from rest of the isolates biochemically and by AP-PCR. This study reports, for the first time, the presence of the emetic toxin gene cesB in B. pumilus.

As espécies de Bacillus constituem um grupo diversificado de bactérias amplamente distribuídas no solo e no ambiente aquático. Neste estudo, cepas de Bacillus isoladas do ambiente costeiro de Cochin, Índia, foram identificadas através de métodos bioquímicos convencionais, análise de ésteres metílicos de ácidos graxos (FAME) e sequenciamento de 16S rDNA. A análise dos dados revelou que Bacillus pumilus foi a espécie predominante na região estudada, seguido de B. cereus e B. sphaericus. Os isolados de B. pumilus foram caracterizados através da reação em cadeia da polimerase com primers arbitrários (AP-PCR), perfil de sensibilidade a antibióticos e triagem por PCR de genes de toxinas associadas com Bacillus spp. Todos os isolados de B. pumilus foram bioquimicamente idênticos, apresentaram elevada atividade de protease e lipase e foram uniformemente sensíveis aos antibióticos estudados. Um dos isolados de B. pumilus apresentou o gene cesB de B. cereus, que não foinão distinguível dos demais isolados por testes bioquímicos nem por AP-PCR. Este é o primeiro relato da presença do gene cesB da toxina eméticaem B. pumilus.