Staphylococcus aureus native mitral valve endocarditis associated with bed bug bites - A case report and review of the literature

Staphylococcus aureus is a leading cause of community acquired bacteremia and infective endocarditis. S. aureus is a part of the normal skin flora in approximately one third of the human population. Infective endocarditis due to S. aureus can cause several complications and is associated with increased mortality. A 48-year-old female with no significant medical history presented with S. aureus bacteremia and native mitral valve endocarditis. Multiple cutaneous skin lesions were identified, which she reported were due to recent bed bug bites. No source of infection was found except for the skin lesions. Her hospital course was complicated by pulmonary and cerebral septic emboli, left pleural empyema, and acute renal injury. We suspected the bed bug skin bites were the most likely source of bacteremia. Bed bugs carry many human pathogens but have not been shown to be a competent vector. We did not find any literature on endocarditis associated with bed bug bites; thus, our case will be a novel finding.

Propionibacterium acnes: Time-to-Positivity in Standard Bacterial Culture From Different Anatomical Sites

BACKGROUND

Propionibacterium acnes infections are likely under-recognized and underreported. This is partly because of low clinical suspicion, perceived non-pathogenicity, or lack of adequate culture incubation time. We conducted a study to assess the optimal incubation period to recover P. acnes from specimens acquired during the workup of suspected clinical infections.

METHODS

A 5-year retrospective chart review was conducted between January 2010 and December 2014 at a single tertiary-care hospital. All patient cases from which P. acnes was recovered were included for analysis. Source of infection, antibiotic use, and culture time-to-positivity (TTP) were recorded.

RESULTS

Implanted devices comprised the single most common source of P. acnes infection. In the majority of cases, P. acnes was the only organism identified. The mean incubation TTP for all isolates was 5.73 days.

CONCLUSIONS

Standard 5-day culture incubation periods are insufficient to recover P. acnes. As a result, P. acnes is likely a much more common etiology of a variety of clinical infections than previously reported.

Use of integrins to date the endometrium

OBJECTIVE

To compare traditional histologic dating criteria of the endometrium with immunohistochemical criteria based on epithelial integrin expression during the menstrual cycle.

DESIGN

Prospective clinical study.

SETTING

An academic teaching hospital.

PATIENT(S)

Fertile and infertile women undergoing endometrial biopsy.

MAIN OUTCOME MEASURE(S)

Immunohistochemical staining intensity and distribution (HSCORE) of three integrins and traditional histologic endometrial dating.

RESULT(S)

In 1,501 endometrial specimens, phase assignment-based integrin staining was 95% and 85% concordant with histology for the proliferative and early secretory phase, respectively, but only 54% and 49% concordant for the middle and late secretory phase, respectively. The greatest disagreement occurred during the midluteal phase. Of 1,090 patients who underwent sampling 6-10 days after detection of a urinary LH surge (corresponding to cycle days 20-24), multiple logistic regression analysis revealed that endometriosis was positively correlated and male factor infertility was negatively correlated with absent beta3 integrin subunit expression. Diagnosis and absent epithelial alpha4beta1 expression were not related. Patient age was not correlated with the incidence of abnormalities in integrin expression.

CONCLUSION(S)

Traditional histologic dating of the endometrium has remained the gold standard for nearly 50 years. Although the use of marker proteins provides additional information and may reflect endometrial function or receptivity, such markers cannot yet replace traditional methods of endometrial assessment.

Nurses' and physicians' narratives about long-term non-malignant pain among men

The aim of this study was to illuminate the meaning of skilled nurses' and physicians' lived experiences in their encounters with men suffering from long-term, non-malignant pain of at least 6 months duration. Seventeen nurses and four physicians participated in the study. A phenomenological-hermeneutic method was used. In the analysis three themes, 'needing to be manly', 'struggling for relief from pain' and 'needing human support' emerged. The phenomenon 'confirmation' was especially important in all three themes. This study indicates that confirmation of the theme 'needing to be manly' means that nurses' and physicians' must have such a relationship with these men that they really feel respected. Confirmation of the theme 'struggling for relief from pain' means that the care givers must convince these men that they really believe each unique individual's narratives. Confirmation of the theme 'needing human support' means that nurses and physicians have to behave in such a way that these men are convinced that the caregivers really care about them. When the men felt confirmation they dared to disclose their pain experiences more honestly. This is a preliminary prerequisite for nurses' and physicians' potential to help these men.

Stat protein transactivation domains recruit p300/CBP through widely divergent sequences

The signal transduction and activator of transcription (Stat) gene family has been highly conserved throughout evolution. Gene duplication and divergence has produced 7 mammalian Stat genes, each of which mediates a distinct process. While some Stat proteins are activated by multiple cytokines, Stat2 is highly specific for responses to type I interferon. We have cloned mouse Stat2 and found that while its sequence was more divergent from its human homologue than any other mouse-human Stat pairs, it was fully functional even in human cells. Overall sequence identity was only 69%, compared with 85-99% similarity for other Stat genes, and several individual domains that still served similar or identical functions in both species were even less well conserved. The coiled-coil domain responsible for interaction with IRF9 was only 65% identical and yet mouse Stat2 interacted with either human or mouse IRF9; the carboxyl terminus was only 30% identical and yet both regions functioned as equal transactivation domains. Both mouse and human transactivation domains recruited the p300/CBP coactivator and were equally sensitive to inhibition by adenovirus E1A protein. Interestingly, the Stat3 carboxyl terminus also functioned as a transactivator capable of recruiting p300/CBP, as does the Stat1 protein, although with widely differing potencies. Yet these proteins share no sequence similarity with Stat2. These data demonstrate that highly diverged primary sequences can serve similar or identical functions, and that the minimal regions of similarity between human and mouse Stat2 may define the critical determinants for function.

Duplicated gene pairs and alleles of class I genes in the Qa2 region of the murine major histocompatibility complex: a comparison

DNA restriction maps of the major histocompatibility complex and hybridization with low copy probes have previously revealed strong homology between the Q6-Q7 and the Q8-Q9 class I gene pairs in the Qa2 region of the C57BL/10 mouse. After DNA sequence analysis of the Q7, Q8 and Q9 genes, we have compared the Q7 gene with its apparent allele, 27.1, from the BALB/c mouse; the 99% homology between Q7 and 27.1 indicates that this is a non-polymorphic gene. Comparison of Q7 with Q9, its homologue in the Q8-Q9 gene pair, revealed greater than 99% homology, thus supporting our proposal that the Qa2 region has evolved by the duplication of gene pairs. Q7 was also found to be homologous (93%) to Q8, the second member of the Q8-Q9 pair. However, the first exon (encoding the leader sequence) as well as the first intron of Q7 and Q8, which are presumably not subject to strong selective pressure, are essentially identical in nucleotide sequence (having only one mismatch), which suggests that greater than 200 bp of DNA may have been exchanged by gene conversion. Furthermore, transcripts of both Q7 and Q8 would have termination codons derived from the exon that normally encodes the transmembrane domain, thus these genes could encode either membrane-bound class I proteins that lack a cytoplasmic protein domain or class I proteins that are secreted.

Adenocarcinoma in Barrett's esophagus after elimination of gastroesophageal reflux

A 56-yr-old man with severe reflux esophagitis, Barrett's esophagus, and a peptic lower esophageal stricture underwent subtotal resection of the Barrett's esophagus with colonic interposition. After the interposition procedure, gastroesophageal reflux was eliminated, as evidenced by absence of clinical and radiographic findings and by the results of a later continuous pH probe recording. Despite the absence of reflux, 8 yr after the colonic interposition the patient was found to have adenocarcinoma in the remnant of the Barrett's esophagus. This case indicates that elimination of gastroesophageal reflux does not necessarily lead to regression of Barrett's mucosa, nor does it prevent development of adenocarcinoma. As a result, patients with Barrett's esophagus should remain under long-term surveillance for dysplasia and adenocarcinoma, even after successful antireflux therapy. If esophagectomy is performed, every attempt should be made to resect all of the esophagus lined by Barrett's mucosa.