Combined tricuspid atresia- AV septal defect-a rare congenital cardiac abnormality.

INTRODUCTION: Congenital heart diseases (CHDs) are one of the most common birth defects worldwide with a prevalence of 1%. CHDs can be classified into cyanotic and acyanotic diseases based on the presence or absence of the characteristic bluish discoloration of skin and mucus membranes. A subset of cyanotic diseases is single ventricle malformations. This group of disorders comprises 1% of all CHDs. A remarkable yet rare and underreported entity of single ventricle malformations is combined tricuspid atresia (TA) and atrioventricular (AV) septal defect which is characterized by the anatomical features of both entities. Combined TA-AV septal malformation was first anatomically described in 1953 and further explored through echocardiography and cardiac catheterization in 1987 and then 1991. Since then, no studies have been documented in the literature prompting us to share our findings. METHODS: Herein we are describing a rare and underreported cardiac lesion based of a retrospective revision of medical charts at the American University of Beirut Medical Center (AUBMC) Children's Heart Center, a tertiary medical center in the Middle East RESULTS: Out of 200 cases with confirmed single ventricle physiology, we identified a few patients with characteristics of combined TA-AV septal defect. Our patients exhibited characteristic echocardiographic findings of primum ASD, VSD, atretic RAVV, and clefted LAVV. CONCLUSION: In short, TA-AV septal defect is a rare, underreported congenital malformation. Tracking our patients' clinical profiles will help improve our understanding of the prognosis of this entity. Our findings may also improve treatment modalities since replacing the left-sided valve is often overlooked if the defect is inaccurately diagnosed. In addition, such findings can help shed light on the embryological development of the rarely encountered variation of AV septal malformation.

Lactobacilli and other gastrointestinal microbiota of Peromyscus leucopus, reservoir host for agents of Lyme disease and other zoonoses in North America.

The cricetine rodent Peromyscus leucopus is an important reservoir for several human zoonoses, including Lyme disease, in North America. Akin to hamsters, the white-footed deermouse has been unevenly characterized in comparison to the murid Mus musculus. To further understanding of P. leucopus' total genomic content, we investigated gut microbiomes of an outbred colony of P. leucopus, inbred M. musculus, and a natural population of P. leucopus. Metagenome and whole genome sequencing were combined with microbiology and microscopy approaches. A focus was the genus Lactobacillus, four diverse species of which were isolated from forestomach and feces of colony P. leucopus. Three of the species-L. animalis, L. reuteri, and provisionally-named species "L. peromysci"-were identified in fecal metagenomes of wild P. leucopus but not discernibly in samples from M. musculus. L. johnsonii, the fourth species, was common in M. musculus but absent or sparse in wild P. leucopus. Also identified in both colony and natural populations were a Helicobacter sp. in feces but not stomach, and a Tritrichomonas sp. protozoan in cecum or feces. The gut metagenomes of colony P. leucopus were similar to those of colony M. musculus at the family or higher level and for major subsystems. But there were multiple differences between species and sexes within each species in their gut metagenomes at orthologous gene level. These findings provide a foundation for hypothesis-testing of functions of individual microbial species and for interventions, such as bait vaccines based on an autochthonous bacterium and targeting P. leucopus for transmission-blocking.

Genome Sequences of Three Lactobacillus Species Strains of the Stomach of the White-Footed Deermouse (Peromyscus leucopus).

Three colony types of Lactobacillus were isolated from the stomach of LL colony stock Peromyscus leucopus deermice, a reservoir for several human zoonoses. Genome sequences revealed two isolates to be new strains of Lactobacillus animalis and Lactobacillus reuteri The third was distinct from known species and was provisionally designated Lactobacillus sp. strain LL6.