RESUMO
Endometriosis should be considered when a female patient reports symptoms of severe pain/tenderness in the pelvic area associated with a frequent need for urination, bloating, vomiting, or nausea. Clinical suspicion is increased if the patient has a history of endometriosis. However, many patients with endometriosis can be asymptomatic, which is why physicians and providers must keep an open mind and have a broad differential. Examinations that aid in the diagnosis of endometriosis include but are not limited to a pelvic examination, an ultrasound, magnetic resonance imaging (MRI), and an exploratory laparoscopy. In this case study, we present a 57-year-old postmenopausal female patient who presented to her obstetrics and gynecology (OBGYN) physician with hot flashes and an abnormal ultrasound revealing an ovarian cyst. Seventeen years prior, at the age of 40, the patient was found to have endometriosis and endometrial polyps and underwent a left oophorectomy. Due to the patient's history, symptoms, and current scans, it was assumed that the present cyst was a complication of endometriosis. Ultimately, the cyst, right ovarian cyst wall, right fallopian tube, and uterine fibroids were surgically removed and sent to pathology. Upon further review of the patient's pathology reports, it was found that the cyst removed was a seromucinous cyst with focal borderline features.
RESUMO
UNLABELLED: Shewanella oneidensis strain MR-1 is a facultative anaerobe that thrives in redox-stratified environments due to its ability to utilize a wide array of terminal electron acceptors. Conversely, the electron donors utilized by S. oneidensis are more limited and include products of primary fermentation such as lactate, pyruvate, formate, and hydrogen. Lactate, pyruvate, and hydrogen metabolisms inS. oneidensis have been described previously, but little is known about the role of formate oxidation in the ecophysiology of these bacteria. Formate is produced by S. oneidensis through pyruvate formate lyase during anaerobic growth on carbon sources that enter metabolism at or above the level of pyruvate, and the genome contains three gene clusters predicted to encode three complete formate dehydrogenase complexes. To determine the contribution of each complex to formate metabolism, strains lacking one, two, or all three annotated formate dehydrogenase gene clusters were generated and examined for growth rates and yields on a variety of carbon sources. Here, we report that formate oxidation contributes to both the growth rate and yield of S. oneidensis through the generation of proton motive force. Exogenous formate also greatly accelerated growth on N-acetylglucosamine, a carbon source normally utilized very slowly by S. oneidensis under anaerobic conditions. Surprisingly, deletion of all three formate dehydrogenase gene clusters enabled growth of S. oneidensis using pyruvate in the absence of a terminal electron acceptor, a mode of growth never before observed in these bacteria. Our results demonstrate that formate oxidation is a fundamental strategy under anaerobic conditions for energy conservation inS. oneidensis. IMPORTANCE: Shewanella species have garnered interest in biotechnology applications for their ability to respire extracellular terminal electron acceptors, such as insoluble iron oxides and electrodes. While much effort has gone into studying the proteins for extracellular electron transport, how electrons generated through the oxidation of organic carbon sources enter this pathway remains understudied. Here, we quantify the role of formate oxidation in the anaerobic physiology of Shewanella oneidensis Formate oxidation contributes to both the growth rate and yield on a variety of carbon sources through the generation of proton motive force. Advances in our understanding of the anaerobic metabolism of S. oneidensis are important for our ability to utilize and engineer this organism for applications in bioenergy, biocatalysis, and bioremediation.