Instructional Models for Course-Based Research Experience (CRE) Teaching.

The course-based research experience (CRE) with its documented educational benefits is increasingly being implemented in science, technology, engineering, and mathematics education. This article reports on a study that was done over a period of 3 years to explicate the instructional processes involved in teaching an undergraduate CRE. One hundred and two instructors from the established and large multi-institutional SEA-PHAGES program were surveyed for their understanding of the aims and practices of CRE teaching. This was followed by large-scale feedback sessions with the cohort of instructors at the annual SEA Faculty Meeting and subsequently with a small focus group of expert CRE instructors. Using a qualitative content analysis approach, the survey data were analyzed for the aims of inquiry instruction and pedagogical practices used to achieve these goals. The results characterize CRE inquiry teaching as involving three instructional models: 1) being a scientist and generating data; 2) teaching procedural knowledge; and 3) fostering project ownership. Each of these models is explicated and visualized in terms of the specific pedagogical practices and their relationships. The models present a complex picture of the ways in which CRE instruction is conducted on a daily basis and can inform instructors and institutions new to CRE teaching.

The HopX (AvrPphE) family of Pseudomonas syringae type III effectors require a catalytic triad and a novel N-terminal domain for function.

Many gram-negative plant pathogenic bacteria employ type III secretion systems to deliver effector proteins directly into the host cell during infection. On susceptible hosts, type III effectors aid pathogen growth by manipulating host defense pathways. On resistant hosts, some effectors can activate specific host disease resistance (R) genes, leading to generation of rapid and effective immune responses. The biochemical basis of these processes is poorly understood. The HopX (AvrPphE) family is a widespread type III effector among phytopathogenic bacteria. We determined that HopX family members are modular proteins composed of a conserved putative cysteine-based catalytic triad and a conserved potential target/cofactor interaction domain. HopX is soluble in host cells. Putative catalytic triad residues are required for avirulence activity on resistant bean hosts and for the generation of a cell-death response in specific Arabidopsis genotypes. The putative target/cofactor interaction domain is also required for these activities. Our data suggest that specific interaction with and modification of a cytosolic host target drives HopX recognition in resistant hosts and may contribute to virulence in susceptible hosts. Surprisingly, the Legionella pneumophila genome was found to contain a protein with similarity to HopX in sequence and domain arrangement, suggesting that these proteins might also contribute to animal pathogenesis and could be delivered to plant and animal hosts by diverse secretion systems.

Multiple pruritic papules from lone star tick larvae bites.

BACKGROUND: Ticks are the second most common vectors of human infectious diseases in the world. In addition to their role as vectors, ticks and their larvae can also produce primary skin manifestations. Infestation by the larvae of ticks is not commonly recognized, with only 3 cases reported in the literature. The presence of multiple lesions and partially burrowed 6-legged tick larvae can present a diagnostic challenge for clinicians. OBSERVATION: We describe a 51-year-old healthy woman who presented to our clinic with multiple erythematous papules and partially burrowed organisms 5 days after exposure to a wooded area in southern Kentucky. She was treated with permethrin cream and the lesions resolved over the following 3 weeks without sequelae. The organism was later identified as the larva of Amblyomma species, the lone star tick. CONCLUSIONS: Multiple pruritic papules can pose a diagnostic challenge. The patient described herein had an unusually large number of pruritic papules as well as tick larvae present on her skin. Recognition of lone star tick larvae as a cause of multiple bites may be helpful in similar cases.

Preferred methods of excess hair removal in pediatric patients with lung transplantation.

BACKGROUND: Hypertrichosis is common among recipients of lung transplantation taking cyclosporine and it poses a special psychosocial problem in children. Children and parents frequently inquire about methods of hair removal. OBJECTIVE: We sought to determine preferred methods of hair removal in this population. METHODS: We distributed a questionnaire to 104 pediatric recipients of lung transplantation. A total of 56 questionnaires (54%) were completed. RESULTS: Of respondents, 91% (51 of 56) experienced hypertrichosis, 75% (38 of 51) of whom attempted treatment. Depilatory cream was the most common hair removal technique (79%, 30 of 38). Shaving, particularly with an electric razor, received the highest ratings of both satisfaction and likelihood of future use. LIMITATIONS: Generalizability is limited by the response rate. Preferred methods according to different hair locations were not evaluated. CONCLUSION: In our pediatric transplantation population, depilatory cream was the most commonly used treatment for hypertrichosis whereas electric shaving had the highest ratings of satisfaction and future use.

Subterfuge and manipulation: type III effector proteins of phytopathogenic bacteria.

Diverse gram-negative bacteria deliver effector proteins into the cells of their eukaryotic hosts using the type III secretion system. Collectively, these type III effector proteins function to optimize the host cell environment for bacterial growth. Type III effector proteins are essential for the virulence of Pseudomonas syringae, Xanthomonas spp., Ralstonia solanacearum and Erwinia species. Type III secretion systems are also found in nonpathogenic pseudomonads and in species of symbiotic nitrogen-fixing Rhizobium. We discuss the functions of type III effector proteins of plant-associated bacteria, with an emphasis on pathogens. Plant pathogens tend to carry diverse collections of type III effectors that likely share overlapping functions. Several effectors inhibit host defense responses. The eukaryotic host targets of only a few type III effector proteins are currently known. We also discuss possible mechanisms for diversification of the suite of type III effector proteins carried by a given bacterial strain.

Infection with mycobacterium abscessus after Mohs micrographic surgery in an immunocompetent patient.

BACKGROUND: Nontuberculous mycobacterial infections are increasing in incidence. They have been reported following multiple procedures, including dialysis, liposuction, soft tissue augmentation, pedicures, public baths, acupuncture, placement of contaminated foreign devices such as the Norplant (Wyeth Pharmaceuticals, Collegetown, PA, USA), intravenous catheters, and during surgery from contamination of medical instruments. OBJECTIVE: We report a case of Mycobacterium abscessus infection presenting as erythematous papules occurring after Mohs micrographic surgery. We also review the literature on nontuberculous mycobacterial infection to discuss common presentations, diagnosis, and treatment options. METHODS/MATERIALS: One case presenting to an outpatient dermatology surgery clinic is presented with extensive review of the medical literature on M. abscessus. RESULTS/CONCLUSION: Infection with nontuberculous mycobacteria can present with varied nonspecific morphologies. A high degree of clinical suspicion is necessary to avoid delays in diagnosis and treatment.

Identification of the heat-shock sigma factor RpoH and a second RpoH-like protein in Sinorhizobium meliloti.

Hybridization to a PCR product derived from conserved sigma-factor sequences led to the identification of two Sinorhizobium meliloti DNA segments that display significant sequence similarity to the family of rpoH genes encoding the sigma(32) (RpoH) heat-shock transcription factors. The first gene, rpoH1, complements an Escherichia coli rpoH mutation. Cells containing an rpoH1 mutation are impaired in growth at 37 degrees C under free-living conditions and are defective in nitrogen fixation during symbiosis with alfalfa. A plasmid-borne rpoH1-gusA fusion increases in expression upon entry of the culture into the stationary phase of growth. The second gene, designated rpoH2, is 42% identical to the S. meliloti rpoH1 gene. Cells containing an rpoH2 mutation have no apparent phenotype under free-living conditions or during symbiosis with the host plant alfalfa. An rpoH2-gusA fusion increases in expression during the stationary phase of growth. The presence of two rpoH-like sequences in S. meliloti is reminiscent of the situation in Bradyrhizobium japonicum, which has three rpoH genes.