Genomic Analysis Points to Multiple Genetic Mechanisms for Non-Transformable Campylobacter jejuni ST-50.

Campylobacter jejuni and Campylobacter coli are well known for their natural competence, i.e., their capacity for the uptake of naked DNA with subsequent transformation. This study identifies non-transformable C. jejuni and C. coli strains from domestic animals and employs genomic analysis to investigate the strain genotypes and their associated genetic mechanisms. The results reveal genetic associations leading to a non-transformable state, including functional DNase genes from bacteriophages and mutations within the cts-encoded DNA-uptake system, which impact the initial steps of the DNA uptake during natural transformation. Interestingly, all 38 tested C. jejuni ST-50 strains from the United States exhibit a high prevalence of non-transformability, and the strains harbor a variety of these genetic markers. This research emphasizes the role of these genetic markers in hindering the transfer of antimicrobial resistance (AMR) determinants, providing valuable insights into the genetic diversity of Campylobacter. As ST-50 is a major clone of C. jejuni globally, we additionally determined the prevalence of the genetic markers for non-transformability among C. jejuni ST-50 from different regions of the world, revealing distinct patterns of evolution and a strong selective pressure on the loss of competence in ST-50 strains, particularly in the agricultural environment in the United States. Our findings contribute to a comprehensive understanding of genetic exchange mechanisms within Campylobacter strains, and their implications for antimicrobial resistance dissemination and evolutionary pathways within specific lineages.

Chronic active Epstein-Barr exacerbated by COVID-19 co-infection.

A 60-year-old Hispanic female was admitted with recurrent fevers, altered mental status, lymphadenopathy, hepatosplenomegaly, and pancytopenia. Initially, sepsis was presumed because of recurrent urinary tract infection with extended-spectrum beta-lactamase Escherichia coli. Despite appropriate therapy, her clinical condition continued to decline. An extensive workup was obtained to determine the source of her ailments. Bone marrow biopsy was negative for leukemia, lymphoma, and myelodysplastic syndrome; fluorescence in situ hybridization and a cytogenetic panel were normal; a lumbar puncture was negative. However, peripheral blood was remarkable for elevated titers for Epstein-Barr virus (EBV) consistent with chronic active EBV. Treatment with valganciclovir showed early positive results, but the patient became co-infected with COVID-19, and her EBV titer increased again, resulting in a precipitous health decline and death.

Transverse Myelitis Associated with Cryptococcus neoformans in an Immunocompetent Patient.

Cryptococcus neoformans is a microscopic fungus that despite its pervasiveness in the environment rarely causes infection in immunocompetent patients. In immunosuppressed patients, infections involving the central nervous system (CNS) usually present as meningitis or meningoencephalitis. Cryptococcal infections are known to cause significant morbidity and mortality in immunosuppressed patients as it is difficult to eradicate even with adequate antifungal treatment. A 44-year-old Hispanic male presented to the hospital with headache, progressive urinary retention, neck and back pain, and right upper and bilateral lower extremity weakness for five days. Imaging revealed small foci in the white matter and revealed diffuse abnormal signal involving the cervical medullary junction extending up to the thoracic spine. Analysis of cerebral spinal fluid (CSF) obtained via lumbar puncture was positive for the Streptococcus antigen with cultures also growing Cryptococcus neoformans. Upon evaluation, patient was not found to be immunocompromised. This report works to highlight an atypical presentation of a cryptococcal CNS infection to raise awareness amongst clinicians hoping to prevent a delay in diagnosis of this disease given its high mortality.

Successful management of fibrosing mediastinitis with severe vascular compromise: Report of two cases and literature review.

Fibrosing mediastinitis is a rare disorder characterized by the invasive proliferation of fibrous tissue within the mediastinum. This fibrosis can result in compression of intrathoracic structures including the pulmonary vasculature leading to clinical symptoms and complications like pulmonary hypertension. Here, we present two cases of young patients with fibrosing mediastinitis complicated by pulmonary artery stenosis requiring medical and endovascular management with excellent results.

Prevalence and risk factors for Enterobacteriaceae in patients hospitalized with community-acquired pneumonia.

BACKGROUND AND OBJECTIVE: Enterobacteriaceae (EB) spp. family is known to include potentially multidrug-resistant (MDR) microorganisms, and remains as an important cause of community-acquired pneumonia (CAP) associated with high mortality. The aim of this study was to determine the prevalence and specific risk factors associated with EB and MDR-EB in a cohort of hospitalized adults with CAP. METHODS: We performed a multinational, point-prevalence study of adult patients hospitalized with CAP. MDR-EB was defined when ≥3 antimicrobial classes were identified as non-susceptible. Risk factors assessment was also performed for patients with EB and MDR-EB infection. RESULTS: Of the 3193 patients enrolled with CAP, 197 (6%) had a positive culture with EB. Fifty-one percent (n = 100) of EB were resistant to at least one antibiotic and 19% (n = 38) had MDR-EB. The most commonly EB identified were Klebsiella pneumoniae (n = 111, 56%) and Escherichia coli (n = 56, 28%). The risk factors that were independently associated with EB CAP were male gender, severe CAP, underweight (body mass index (BMI) < 18.5) and prior extended-spectrum beta-lactamase (ESBL) infection. Additionally, prior ESBL infection, being underweight, cardiovascular diseases and hospitalization in the last 12 months were independently associated with MDR-EB CAP. CONCLUSION: This study of adults hospitalized with CAP found a prevalence of EB of 6% and MDR-EB of 1.2%, respectively. The presence of specific risk factors, such as prior ESBL infection and being underweight, should raise the clinical suspicion for EB and MDR-EB in patients hospitalized with CAP.

Primary afferent and spinal cord expression of gastrin-releasing peptide: message, protein, and antibody concerns.

There is continuing controversy relating to the primary afferent neurotransmitter that conveys itch signals to the spinal cord. Here, we investigated the DRG and spinal cord expression of the putative primary afferent-derived "itch" neurotransmitter, gastrin-releasing peptide (GRP). Using ISH, qPCR, and immunohistochemistry, we conclude that GRP is expressed abundantly in spinal cord, but not in DRG neurons. Titration of the most commonly used GRP antiserum in tissues from wild-type and GRP mutant mice indicates that the antiserum is only selective for GRP at high dilutions. Paralleling these observations, we found that a GRPeGFP transgenic reporter mouse has abundant expression in superficial dorsal horn neurons, but not in the DRG. In contrast to previous studies, neither dorsal rhizotomy nor an intrathecal injection of capsaicin, which completely eliminated spinal cord TRPV1-immunoreactive terminals, altered dorsal horn GRP immunoreactivity. Unexpectedly, however, peripheral nerve injury induced significant GRP expression in a heterogeneous population of DRG neurons. Finally, dual labeling and retrograde tracing studies showed that GRP-expressing neurons of the superficial dorsal horn are predominantly interneurons, that a small number coexpress protein kinase C gamma (PKCγ), but that none coexpress the GRP receptor (GRPR). Our studies support the view that pruritogens engage spinal cord "itch" circuits via excitatory superficial dorsal horn interneurons that express GRP and that likely target GRPR-expressing interneurons. The fact that peripheral nerve injury induced de novo GRP expression in DRG neurons points to a novel contribution of this peptide to pruritoceptive processing in neuropathic itch conditions.

Presentación clínica de las cardiopatías congénitas en prematuros menores de 1500 gr atendidos en el Servicio de Neonatología del Hospital Arzobispo Loayza en el periodo comprendido de junio 2008 a junio 2013 / Clinical presentation of congenital heart disease in preterm infants less than 1500 grams treated in the Neonatology Service at the Hospital Arzobispo Loayza in the period from June 2008 to June 2013

Contenido: Se realizó un estudio descriptivo y retrospectivo de las ciencias médicas cuyo objetivo es identificar las manifestaciones clínicas de las Cardiopatías Congénitas en los Prematuros menores de 1500gr atendidos en el Hospital Arzobispo Loayza en el periodo comprendido de junio del 2008 a junio del 2013. Se recolecto 289 pacientes, siendo 157 prematuros (54.2 por ciento) del sexo masculino, procediendo la mayoría de Lima Metropolitana (48.5 por ciento) seguido de Trujillo y Chiclayo respectivamente, el 80 por ciento es de muy bajo peso al nacer, siendo la Cardiopatía Congénita más frecuente la Persistencia del Conducto arterioso (PCA) con 82.8 por ciento, seguido de Comunicación intraventricular (CIV) con 8.5 por ciento. En cuanto a los factores de riesgo no se encontró relación a la edad de los padres, ni los controles prenatales, pero si la cuarta parte presentaba antecedentes de cardiopatía congénitas. El 47 por ciento de los padres toxicómanos tenía antecedentes de tabaquismo, no se encontró correlación entre valoración del Apgar y el tipo de parto con malformaciones cardiovasculares. Finalmente dentro de la presentación clínica, predomina la dificultad respiratoria en 17.1 por ciento, seguida de cardiomegalia con 14.3 por ciento, la cuarta parte del total de pacientes no presentaron sintomatología. El diagnóstico en el 100 por ciento de los casos se realizó por Ecocardiografía.

Content: A descriptive, retrospective study of medical sciences was performed aimed at identifying the clinical manifestations of Congenital Heart Disease in Premature under 1500gr treated at the Archbishop Loayza Hospital in the period June 2008 to June 2013. We collected 289 patients, with 157 preterm (54.2 per cent) were male, carrying most of Lima (48.5 per cent) followed by Trujillo and Chiclayo respectively, 80 per cent is of very low birth weight, congenital heart disease being the most frequent the ductus arteriosus (PCA) with 82.8 per cent followed by, intraventricular septal defect (VSD) with 8.5 per cent as for risk factors not related to parental age, or prenatal care was found, but if the quarter had a history of congenital heart disease. 47 per cent of drug users had a history of smoking parents, no correlation between Apgar assessment and mode of delivery with cardiovascular malformations were found. Finally within the clinical presentation, the predominant respiratory distress in 17.1 per cent, followed by cardiomegaly with 14.3 per cent, a quarter of all patients had no symptoms. The diagnosis in 100 per cent of cases was performed by echocardiography.

Trail pheromone of the Argentine ant, Linepithema humile (Mayr) (Hymenoptera: Formicidae).

The Argentine ant (Linepithema humile) is recognized as one of the world's most damaging invasive species. One reason for the ecological dominance of introduced Argentine ant populations is their ability to dominate food and habitat resources through the rapid mobilization and recruitment of thousands of workers. More than 30 years ago, studies showed that (Z)-9-hexadecenal strongly attracted Argentine ant workers in a multi-choice olfactometer, suggesting that (Z)-9-hexadecenal might be the trail pheromone, or a component of a trail pheromone mixture. Since then, numerous studies have considered (Z)-9-hexadecenal as the key component of the Argentine ant trails. Here, we report the first chemical analyses of the trails laid by living Argentine ants and find that (Z)-9-hexadecenal is not present in a detectible quantity. Instead, two iridoids, dolichodial and iridomyrmecin, appear to be the primary chemical constituents of the trails. Laboratory choice tests confirmed that Argentine ants were attracted to artificial trails comprised of these two chemicals significantly more often than control trails. Although (Z)-9-hexadecenal was not detected in natural trails, supplementation of artificial dolichodial+iridomyrmecin trails with an extremely low concentraion of (Z)-9-hexadecenal did increase the efficacy of the trail-following behavior. In stark contrast with previous dogma, our study suggests that dolichodial and iridomyrmecin are major components of the Argentine ant trail pheromone. (Z)-9-hexadecenal may act in an additive manner with these iridoids, but it does not occur in detectable quantities in Argentine ant recruitment trails.