Disruption of Biofilm by Bacteriophages in Clinically Relevant Settings.

INTRODUCTION: Antibiotic-resistant bacteria are a growing threat to civilian and military health today. Although infections were once easily treatable by antibiotics and wound cleaning, the frequent mutation of bacteria has created strains impermeable to antibiotics and physical attack. Bacteria further their pathogenicity because of their ability to form biofilms on wounds, medical devices, and implant surfaces. Methods for treating biofilms in clinical settings are limited, and when formed by antibiotic-resistant bacteria, can generate chronic infections that are recalcitrant to available therapies. Bacteriophages are natural viral predators of bacteria, and their ability to rapidly destroy their host has led to increased attention in potential phage therapy applications. MATERIALS AND METHODS: The present article sought to address a knowledge gap in the available literature pertaining to the usage of bacteriophage in clinically relevant settings and the resolution of infections particular to military concerns. PRISMA guidelines were followed for a systematic review of available literature that met the criteria for analysis and inclusion. The research completed for this review article originated from the U.S. Military Academy's library "Scout" search engine, which complies results from 254 available databases (including PubMed, Google Scholar, and SciFinder). The search criteria included original studies that employed bacteriophage use against biofilms, as well as successful phage therapy strategies for combating chronic bacterial infections. We specifically explored the use of bacteriophage against antibiotic- and treatment-resistant bacteria. RESULTS: A total of 80 studies were identified that met the inclusion criteria following PRISMA guidelines. The application of bacteriophage has been demonstrated to robustly disrupt biofilm growth in wounds and on implant surfaces. When traditional therapies have failed to disrupt biofilms and chronic infections, a combination of these treatments with phage has proven to be effective, often leading to complete wound healing without reinfection. CONCLUSIONS: This review article examines the available literature where bacteriophages have been utilized to treat biofilms in clinically relevant settings. Specific attention is paid to biofilms on implant medical devices, biofilms formed on wounds, and clinical outcomes, where phage treatment has been efficacious. In addition to the clinical benefit of phage therapies, the military relevance and treatment of combat-related infections is also examined. Phages offer the ability to expand available treatment options in austere environments with relatively low cost and effort, allowing the impacted warfighter to return to duty quicker and healthier.

Reverse evolution of armor plates in the threespine stickleback.

Faced with sudden environmental changes, animals must either adapt to novel environments or go extinct. Thus, study of the mechanisms underlying rapid adaptation is crucial not only for the understanding of natural evolutionary processes but also for the understanding of human-induced evolutionary change, which is an increasingly important problem [1-8]. In the present study, we demonstrate that the frequency of completely plated threespine stickleback fish (Gasterosteus aculeatus) has increased in an urban freshwater lake (Lake Washington, Seattle, Washington) within the last 40 years. This is a dramatic example of "reverse evolution,"[9] because the general evolutionary trajectory is toward armor-plate reduction in freshwater sticklebacks [10]. On the basis of our genetic studies and simulations, we propose that the most likely cause of reverse evolution is increased selection for the completely plated morph, which we suggest could result from higher levels of trout predation after a sudden increase in water transparency during the early 1970s. Rapid evolution was facilitated by the existence of standing allelic variation in Ectodysplasin (Eda), the gene that underlies the major plate-morph locus [11]. The Lake Washington stickleback thus provides a novel example of reverse evolution, which is probably caused by a change in allele frequency at the major plate locus in response to a changing predation regime.

Endometrial eosinophilic syncytial change related to breakdown: immunohistochemical evidence suggests a regressive process.

Eosinophilic syncytial change (ESC), also known as papillary syncytial change, occurs in association with endometrial breakdown and bleeding, especially in nonphysiological conditions. When prominent, this morphological alteration yields a pattern of eosinophilic epithelial cells, often in pseudopapillary arrangements that can mimic cellular changes seen in metaplastic and atypical endometrium. To determine if ESC represents a proliferative, regenerative process or a degenerative, retrogressive alteration, we assessed whether the cells of ESC were actively growing. Our methodology involved a retrospective immunohistochemical study on endometrial biopsies with proliferation markers Ki-67 (MIB-1 antibody) and phosphohistone H3 Ser 28 (pHH3) in 15 cases of multifocal ESC associated with benign endometrium, 5 cases of atypical hyperplasia, and 7 cases of endometrial carcinoma. The Ki-67 proliferative index and the pHH3 mitotic index were calculated per 100 cells for each case. On immunohistochemical analysis, the Ki-67 labeling index was 1.3% for cases of ESC (mean age, 53 yr), 15.8% in atypical hyperplasia (mean age, 51.6 yr), and 42.6% in endometrial carcinoma (mean age, 68.1 yr). In the endometrial cancers, the Ki-67 proliferative index was 10.6% for FIGO grade 1 tumors (n=3), 27.6% for grade 2 tumor (n=1), and 79.6% for serous carcinoma (n=3). The mitotic index calculated from pHH3 immunostaining was zero in all cases of ESC, whereas it was 2.3% in atypical hyperplasia and 4.8% in endometrial carcinomas (2.4% for grade 1, 3% for grade 2, and 7.8% for serous). Our results indicate that ESC is a regressive change. Furthermore, when there is a question of whether eosinophilic endometrial epithelium represents this change, a combination of Ki-67 and pHH3 immunostains can be helpful in distinguishing this entity from more significant processes including carcinoma.

Adenocarcinoma in situ arising in vulvar papillary hidradenoma: report of 2 cases.

Adenocarcinoma in situ rarely occurs in vulvar papillary hidradenoma. We encountered 2 cases of adenocarcinoma in situ arising in a papillary hidradenoma of the vulva. Both patients were asymptomatic women, aged 83 and 92 years, who presented with nodules (1.0 and 2.0 cm) on the vulva. Macroscopically, the lesions seemed tan-pink, fleshy, and well circumscribed. One tumor ulcerated the overlying epidermis. On microscopic examination, the tumors showed focal features of benign hidradenoma at the periphery with transitions into areas of increasing cytologic atypia that fulfilled criteria for adenocarcinoma in situ similar to that seen in the breast. One tumor showed a predominant cribriform pattern with moderate atypia and many mitoses; the other showed a mixture of cribriform and micropapillary patterns, mild atypia, and fewer mitotic figures. There was no evidence of destructive invasion or desmoplasia in either tumor. Both lesions show areas strongly immunoreactive for mammaglobin and gross cystic disease fluid protein 15 as well as estrogen and progesterone receptor protein in 1 case. There was no evidence of benign ectopic breast tissue within or adjacent to the neoplasms. Both patients underwent local excision with no evidence of tumor recurrence at 15 and 32 months of follow-up. The fact that these tumors displayed morphologic and immunohistochemical features that resembled ductal carcinoma in situ of the breast demonstrates the close homology between papillary hidradenoma and breast epithelium. In the absence of invasion, our experience suggests that these tumors can be cured by local excision.

Complete sequence and comparative genome analysis of the dairy bacterium Streptococcus thermophilus.

The lactic acid bacterium Streptococcus thermophilus is widely used for the manufacture of yogurt and cheese. This dairy species of major economic importance is phylogenetically close to pathogenic streptococci, raising the possibility that it has a potential for virulence. Here we report the genome sequences of two yogurt strains of S. thermophilus. We found a striking level of gene decay (10% pseudogenes) in both microorganisms. Many genes involved in carbon utilization are nonfunctional, in line with the paucity of carbon sources in milk. Notably, most streptococcal virulence-related genes that are not involved in basic cellular processes are either inactivated or absent in the dairy streptococcus. Adaptation to the constant milk environment appears to have resulted in the stabilization of the genome structure. We conclude that S. thermophilus has evolved mainly through loss-of-function events that remarkably mirror the environment of the dairy niche resulting in a severely diminished pathogenic potential.

Endometrial hyperplasia/adenocarcinoma. a conventional approach.

Hyperplasia of the endometrium is a process characterized by an irregular, noninvasive proliferation of glands with a variable amount of stroma. Precise classification of endometrial hyperplasia in biopsy material is important in order to identify those hyperplasias that are likely to be precursors of endometrial adenocarcinoma. The current World Health Organization (WHO) classification provides a scheme that has become widely accepted, primarily dividing hyperplasias in to those with and those without cytologic atypia while the degree of glandular crowding (simple vs. complex) has secondary importance. A wide variety of other endometrial changes, ranging from artifacts, metaplasias and polyps to well-differentiated adenocarcinoma must be considered in the differential diagnosis. Well-differentiated adenocarcinoma is diagnosed when one of 3 essential criteria is found in biopsy specimens: (1) a confluent gland pattern; (2) an extensive papillary pattern; or (3) a desmoplastic stromal response. Using the WHO classification allows segregation of endometrial hyperplasia into clinically meaningful categories. Strict morphologic criteria also enable separation of hyperplasia from well-differentiated adenocarcinoma.

Genome sequence of Bacillus cereus and comparative analysis with Bacillus anthracis.

Bacillus cereus is an opportunistic pathogen causing food poisoning manifested by diarrhoeal or emetic syndromes. It is closely related to the animal and human pathogen Bacillus anthracis and the insect pathogen Bacillus thuringiensis, the former being used as a biological weapon and the latter as a pesticide. B. anthracis and B. thuringiensis are readily distinguished from B. cereus by the presence of plasmid-borne specific toxins (B. anthracis and B. thuringiensis) and capsule (B. anthracis). But phylogenetic studies based on the analysis of chromosomal genes bring controversial results, and it is unclear whether B. cereus, B. anthracis and B. thuringiensis are varieties of the same species or different species. Here we report the sequencing and analysis of the type strain B. cereus ATCC 14579. The complete genome sequence of B. cereus ATCC 14579 together with the gapped genome of B. anthracis A2012 enables us to perform comparative analysis, and hence to identify the genes that are conserved between B. cereus and B. anthracis, and the genes that are unique for each species. We use the former to clarify the phylogeny of the cereus group, and the latter to determine plasmid-independent species-specific markers.