A lipoprotein modulates activity of the MtrAB two-component system to provide intrinsic multidrug resistance, cytokinetic control and cell wall homeostasis in Mycobacterium.

The MtrAB signal transduction system, which participates in multiple cellular processes related to growth and cell wall homeostasis, is the only two-component system known to be essential in Mycobacterium. In a screen for antibiotic resistance determinants in Mycobacterium smegmatis, we identified a multidrug-sensitive mutant with a transposon insertion in lpqB, the gene located immediately downstream of mtrA-mtrB. The lpqB mutant exhibited increased cell-cell aggregation and severe defects in surface motility and biofilm growth. lpqB cells displayed hyphal growth and polyploidism, reminiscent of the morphology of Streptomyces, a related group of filamentous Actinobacteria. Heterologous expression of M. tuberculosis LpqB restored wild-type characteristics to the lpqB mutant. LpqB interacts with the extracellular domain of MtrB, and influences MtrA phosphorylation and promoter activity of dnaA, an MtrA-regulated gene that affects cell division. Furthermore, in trans expression of the non-phosphorylated, inactive form of MtrA in wild-type M. smegmatis resulted in phenotypes similar to those of lpqB deletion, whereas expression of the constitutively active form of MtrA restored wild-type characteristics to the lpqB mutant. These results support a model in which LpqB, MtrB and MtrA form a three-component system that co-ordinates cytokinetic and cell wall homeostatic processes.

Pancreatitis After Pancreaticojejunostomy Procedure? A Tale Involving the Tail of the Pancreas.

Recurrent acute pancreatitis (RAP) involving the tail of the pancreas after pancreaticojejunosotomy (PJP) is rare, has very challenging management, and there is minimal literature. We describe a case of idiopathic RAP, complicated with chronic pancreatitis that failed medical and endoscopic management and required PJP. Unfortunately, RAP recurred after PJP, and we describe his clinical course and management.

Protein kinase G is required for intrinsic antibiotic resistance in mycobacteria.

Antibiotic resistance and virulence of pathogenic mycobacteria are phenotypically associated, but the underlying genetic linkage has not been known. Here we show that PknG, a eukaryotic-type protein kinase previously found to support survival of mycobacteria in host cells, is required for the intrinsic resistance of mycobacterial species to multiple antibiotics.

Long-term esophageal and respiratory outcomes in children with esophageal atresia and tracheoesophageal fistula.

OBJECTIVES: Few studies have evaluated the long-term complications and outcomes of esophageal atresia with or without tracheoesophageal fistula (EA/TEF) beyond childhood. The aim of our study was to characterize the esophageal and respiratory morbidity of EA/TEF through evaluation of clinical symptoms, diagnostic testing and therapeutic intervention at a tertiary care center. METHODS: Patients with congenital EA/TEF evaluated from 2011 to 2014 were included. Demographic characteristics, type and mode of repair of EA/TEF, clinical symptoms, radiographic, endoscopic, bronchoscopic and medication use data were obtained. RESULTS: A total of 43 patients were identified. The median age of this predominantly Caucasian population was 8 years (interquartile range: 3, 20). Twenty (62.5%) had type C (EA with distal TEF) abnormality. Twenty-one (48.8%) patients had heartburn, 19 (44.1%) had acid regurgitation, and 31 (72.1%) had dysphagia to solids. Barium swallow in 26 patients revealed strictures in 17 (65.4%), dysmotility in 20 (76.9%) and recurrent fistulas in four patients (15.4%). Thirty patients underwent upper endoscopy, of which 21 (70.0%) had a stricture, and six (20.0%) had recurrent fistula requiring surgical intervention. Eight (18.6%) patients underwent fundoplication. Pulmonary evaluation showed cough and choking in 31 (72.1%) patients and dyspnea and wheezing in 32 (53.4%) patients. Recurrent respiratory infections were reported in 19 (44.2%). PATIENTS: Other findings included tracheomalacia in 86.7% and restrictive lung disease in 54.5% of patients. CONCLUSION: There is a high burden of residual esophageal and pulmonary pathology in patients with EA/TEF. Ongoing follow-up is required to monitor both the clinical symptoms and treatment responses.

A rare cause of gastro-intestinal hemorrhage in a patient with a Roux-en-Y gastric bypass.

This case illustrates a rare cause of gastro-intestinal bleeding following bariatric surgery. Though it is essential to rule out common causes of variceal formation accompanied by intermittent, profuse bleeding, there should be a high degree of suspicion of this rare etiology in patients who have previously undergone alteration of their anatomy, especially Roux-en-Y gastric bypass (RYGB). The case emphasizes the need for a multidisciplinary medical-surgical team in evaluating and treating patients who present with complex intra-abdominal pathology.