Vibrio cholerae Alkalizes Its Environment via Citrate Metabolism to Inhibit Enteric Growth In Vitro

Vibrio cholerae is a Gram-negative pathogen, living in constant competition with other bacteria in marine environments and during human infection. One competitive advantage of V. cholerae is the ability to metabolize diverse carbon sources, such as chitin and citrate. We observed that when some V. cholerae strains were grown on a medium with citrate, the medium's chemical composition turned into a hostile alkaline environment for Gram-negative bacteria, such as Escherichia coli and Shigella flexneri. We found that although the ability to exclude competing bacteria was not contingent on exogenous citrate, V. cholerae C6706 citrate metabolism mutants ΔoadA-1, ΔcitE, and ΔcitF were not able to inhibit S. flexneri or E. coli growth. Lastly, we demonstrated that while the V. cholerae C6706-mediated increased medium pH was necessary for the enteric exclusion phenotype, secondary metabolites, such as bicarbonate (protonated to carbonate in the raised pH) from the metabolism of citrate, enhanced the ability to inhibit the growth of E. coli. These data provide a novel example of how V. cholerae outcompetes other Gram-negative bacteria. IMPORTANCE Vibrio cholerae must compete with other bacteria in order to cause disease. Here, we show that V. cholerae creates an alkaline environment, which is able to inhibit the growth of other enteric bacteria. We demonstrate that V. cholerae environmental alkalization is linked to the capacity of the bacteria to metabolize citrate. This behavior could potentially contribute to V. cholerae's ability to colonize the human intestine.

An immunoPET probe to SARS-CoV-2 reveals early infection of the male genital tract in rhesus macaques

The systemic nature of SARS-CoV-2 infection is highly recognized, but poorly characterized. A non-invasive and unbiased method is needed to clarify whole body spatiotemporal dynamics of SARS-CoV-2 infection after transmission. We recently developed a probe based on the anti-SARS-CoV-2 spike antibody CR3022 to study SARS-CoV-2 pathogenesis in vivo. Herein, we describe its use in immunoPET to investigate SARS-CoV-2 infection of three rhesus macaques. Using PET/CT imaging of macaques at different times post-SARS-CoV-2 inoculation, we track the 64Cu-labelled CR3022-F(ab')2 probe targeting the spike protein of SARS-CoV-2 to study the dynamics of infection within the respiratory tract and uncover novel sites of infection. Using this method, we uncovered differences in lung pathology between infection with the WA1 isolate and the delta variant, which were readily corroborated through computed tomography scans. The 64Cu-CR3022-probe also demonstrated dynamic changes occurring between 1- and 2-weeks post-infection. Remarkably, a robust signal was seen in the male genital tract (MGT) of all three animals studied. Infection of the MGT was validated by immunofluorescence imaging of infected cells in the testicular and penile tissue and severe pathology was observed in the testes of one animal at 2-weeks post-infection. The results presented here underscore the utility of using immunoPET to study the dynamics of SARS-CoV-2 infection to understand its pathogenicity and discover new anatomical sites of viral replication. We provide direct evidence for SARS-CoV-2 infection of the MGT in rhesus macaques revealing the possible pathologic outcomes of viral replication at these sites.

An immunoPET probe to SARS-CoV-2 reveals early infection of the male genital tract in rhesus macaques

The systemic nature of SARS-CoV-2 infection is highly recognized, but poorly characterized. A non-invasive and unbiased method is needed to clarify whole body spatiotemporal dynamics of SARS-CoV-2 infection after transmission. We recently developed a probe based on the anti-SARS-CoV-2 spike antibody CR3022 to study SARS-CoV-2 pathogenesis in vivo. Herein, we describe its use in immunoPET to investigate SARS-CoV-2 infection of three rhesus macaques. Using PET/CT imaging of macaques at different times post-SARS-CoV-2 inoculation, we track the 64Cu-labelled CR3022-F(ab')2 probe targeting the spike protein of SARS-CoV-2 to study the dynamics of infection within the respiratory tract and uncover novel sites of infection. Using this method, we uncovered differences in lung pathology between infection with the WA1 isolate and the delta variant, which were readily corroborated through computed tomography scans. The 64Cu-CR3022-probe also demonstrated dynamic changes occurring between 1- and 2-weeks post-infection. Remarkably, a robust signal was seen in the male genital tract (MGT) of all three animals studied. Infection of the MGT was validated by immunofluorescence imaging of infected cells in the testicular and penile tissue and severe pathology was observed in the testes of one animal at 2-weeks post-infection. The results presented here underscore the utility of using immunoPET to study the dynamics of SARS-CoV-2 infection to understand its pathogenicity and discover new anatomical sites of viral replication. We provide direct evidence for SARS-CoV-2 infection of the MGT in rhesus macaques revealing the possible pathologic outcomes of viral replication at these sites.

Development of an In Vivo Probe to Track SARS-CoV-2 Infection in Rhesus Macaques

Infection with the novel coronavirus, SARS-CoV-2, results in pneumonia and other respiratory symptoms as well as pathologies at diverse anatomical sites. An outstanding question is whether these diverse pathologies are due to replication of the virus in these anatomical compartments and how and when the virus reaches those sites. To answer these outstanding questions and study the spatiotemporal dynamics of SARS-CoV-2 infection a method for tracking viral spread in vivo is needed. We developed a novel, fluorescently labeled, antibody-based in vivo probe system using the anti-spike monoclonal antibody CR3022 and demonstrated that it could successfully identify sites of SARS-CoV-2 infection in a rhesus macaque model of COVID-19. Our results showed that the fluorescent signal from our antibody-based probe could differentiate whole lungs of macaques infected for 9 days from those infected for 2 or 3 days. Additionally, the probe signal corroborated the frequency and density of infected cells in individual tissue blocks from infected macaques. These results provide proof of concept for the use of in vivo antibody-based probes to study SARS-CoV-2 infection dynamics in rhesus macaques.

Functional landscape of SARS-CoV-2 cellular restriction

A deficient interferon (IFN) response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been implicated as a determinant of severe coronavirus disease 2019 (COVID-19). To identify the molecular effectors that govern IFN control of SARS-CoV-2 infection, we conducted a large-scale gain-of-function analysis that evaluated the impact of human IFN-stimulated genes (ISGs) on viral replication. A limited subset of ISGs were found to control viral infection, including endosomal factors inhibiting viral entry, RNA binding proteins suppressing viral RNA synthesis, and a highly enriched cluster of endoplasmic reticulum (ER)/Golgi-resident ISGs inhibiting viral assembly/egress. These included broad-acting antiviral ISGs and eight ISGs that specifically inhibited SARS-CoV-2 and SARS-CoV-1 replication. Among the broad-acting ISGs was BST2/tetherin, which impeded viral release and is antagonized by SARS-CoV-2 Orf7a protein. Overall, these data illuminate a set of ISGs that underlie innate immune control of SARS-CoV-2/SARS-CoV-1 infection, which will facilitate the understanding of host determinants that impact disease severity and offer potential therapeutic strategies for COVID-19.

Detection of bluetongue virus RNA in field-collected Culicoides spp. (Diptera: Ceratopogonidae) following the discovery of bluetongue virus serotype 1 in white-tailed deer and cattle in Louisiana

In November 2004, bluetongue virus (family Reoviridae, genus Orbivirus, BTV) serotype 1 (BTV-1) was detected for the first time in the United States from a hunter-killed deer in St. Mary Parish, LA. In 2005, sera surveys were conducted on three cattle farms near the area where the deer was found, and BTV-1-seropositive cattle were found on two of the three farms; in 2006, sera surveys from the cattle on the three farms did not detect any BTV-1-positive animals. The purpose of this study was to survey ceratopogonid populations at the three farms and test field-collected specimens for the presence of BTV and epizootic hemorrhagic disease virus (family Reoviridae, genus Orbivirus, EHDV). Miniature CDC light traps and New Jersey traps were used to capture ceratopogonids on the three farms from January 2006 through November 2007. In total, 3,319 ceratopogonids were captured, including 1,790 specimens of 10 different species of Culicoides. IR-RT-polymerase chain reaction (PCR) was performed to screen for BTV and EHDV in 264 pools representing 2,309 specimens collected at the farms. All positive samples were sequenced for serotype determination. Five pools of 275 (1.8%) were positive for BTV. Pools of four species of Culicoides were found to be positive: Culicoides crepuscularis (Malloch), Culicoides debilipalpis Lutz (two pools), Culicoides haematopotus Malloch, and Gulicoidesfurens (Poey). The amplicons of the positive specimens were sequenced and found to be identical to both BTV-17 and BTV-13. During our study, no BTV-1 transmission was detected in cattle, and no BTV-1 was detected in specimens of ceratopogonids.

Olanzapine in the treatment of post-traumatic stress disorder: a pilot study

Because the atypical antipsychotic olanzapine may be efficacious in treating post-traumatic stress disorder (PTSD) symptoms, we conducted a 10-week, double-blind, placebo-controlled evaluation in which 15 patients were randomized 2:1 to either olanzapine or placebo. The initial dosage was 5 mg/day and was titrated to a maximum of 20 mg/day. Eleven patients completed the study. Patients in both groups showed improvement in PTSD symptoms, but no between-group differences in treatment response were observed and a high placebo response rate was found. Both treatments were tolerated well, although the olanzapine treatment group had more weight gain. Olanzapine fared no better than placebo in this preliminary study in the treatment of PTSD. The lack of difference between olanzapine and placebo may in part be due to olanzapine's not being effective in PTSD or, alternatively, a small sample size, a high placebo response in certain forms of PTSD and the chronicity of PTSD symptoms in some patients.

Short-course induction chemoradiotherapy with paclitaxel for stage III non-small-cell lung cancer

BACKGROUND

This study assessed toxicity, tumor response, disease control, and survival after short-course induction chemoradiotherapy and surgical resection in patients with stage III non-small-cell lung carcinoma.

METHODS

Forty-five patients with stage III non-small-cell lung carcinoma received 12-day induction therapy of a 96-hour continuous infusion of cisplatin (20 mg/m2 per day), 24-hour infusion of paclitaxel (175 mg/m2), and concurrent accelerated fractionation radiation therapy (1.5 Gy twice daily) to a dose of 30 Gy. Surgical resection was scheduled for 4 weeks later. Postoperatively, a second identical course of chemotherapy and concurrent radiation therapy (30 to 33 Gy) was given.

RESULTS

Induction toxicity resulted in hospitalization of 18 (40%) patients for neutropenic fever. No induction deaths occurred. Of 40 (89%) patients who underwent thoracotomy, resection for cure was possible in 32 (71%) patients. Pathologic response was noted in 21 (47%) patients, and 14 (31%) were downstaged to mediastinal node negative (stage 0, I, or II). At a median follow-up of 19 months, 24 patients were alive, 10 with recurrent disease. Of 21 deaths, 16 were from recurrent disease, three were from treatment, and two were unrelated. Recurrent disease was distant in 21 patients, distant and locoregional in 2, and locoregional in 3. The Kaplan-Meier projected 24-month survival is 49%. Projected 24-month survival is 61% for stage IIIA, 17% for stage IIIB (p = 0.035); 84% for pathologic responders, 22% for nonresponders (p<0.001); 83% for downstaged patients (stage 0, I, or II), 33% for those not downstaged (p = 0.005); and 63% for resectable patients, 14% for unresectable patients (p = 0.007).

CONCLUSIONS

We conclude that short-course neoadjuvant therapy with paclitaxel (1) has manageable toxicity and a low treatment mortality, (2) results in good tumor response and downstaging, (3) provides excellent locoregional control with most recurrences being distant, and (4) has improved the median survival compared with historical controls. Survival was better in stage IIIA patients, resectable patients, pathologic responders, and patients downstaged to mediastinal node negative disease (stage 0, I, or II).

Antimyeloperoxidase antibodies induce neutrophil adherence to cultured human endothelial cells

Antimyeloperoxidase autoantibodies are found in the sera of some patients with glomerulonephritis and systemic vasculitis. Previously, we demonstrated that they were able to stimulate neutrophils to damage cultured human endothelial cells. We now report that antimyeloperoxidase antibodies are able to stimulate neutrophils to adhere to cultured human endothelial cells. Immunoglobulin G purified from myeloperoxidase-antineutrophil cytoplasmic autoantibody positive sera increased adherence to 331 +/- 60% of unstimulated controls. In a similar manner, rabbit antimyeloperoxidase enhanced neutrophil adherence. Stimulating the endothelial cells with 10 micrograms/mL endotoxin enhanced antimyeloperoxidase stimulated adherence. In the presence of a CD18 blocking antibody (MoAb 60.3), antimyeloperoxidase-stimulated adherence was significantly decreased. These results add further understanding to the antimyeloperoxidase-stimulated neutrophil-endothelial cell interaction and further support the hypothesis that antimyeloperoxidase autoantibodies are of pathogenic import in glomerulonephritis and vasculitis.

Behavioural psychotherapy of the frontal-lobe-injured patient in an outpatient setting

We present two cases of outpatient behavioural psychotherapy of frontal-lobe brain-injured adults. Unlike inpatient treatment of severely frontal-injured patients in which the hospital setting acts on the patient to modify behaviour, outpatient treatment teaches the self-motivated individual to use the structure and directiveness of behavioural psychotherapy to overcome his or her neuropsychological deficits. The literature describes two types of frontal syndromes: disinhibition and adynamia. Treatment of both types of syndromes is illustrated using case presentations. The therapeutic interventions for both syndromes are designed to exaggerate the link between stimulus and response to counter impaired processing of feedback. A six-stage behavioural psychotherapy model of the frontal-injured patient is outlined.

Candida epiglottitis

Acute epiglottitis is most commonly of bacterial origin. A case of Candida epiglottis in a healthy, nondebilitated patient is reported. A literature search did not produce a previously reported case.

Validity of spinal cord examination as a substitute procedure for routine rabies diagnosis

A significant portion of specimens received by this laboratory for rabies diagnosis is unsatisfactory for testing due to decomposition of the brain, or severe mutilation of the head when the animal was killed. Examination of the spinal cord was therefore explored as a possible alternative method when standard brain examination was not possible. In this study, both brain and spinal cord of 248 rabies-suspect animals were examined to assess the reliability of the spinal cord method. Brain and spinal cord of the 248 animals were examined by fluorescent antibody (FA) method, and mouse inoculation tests were performed on 247 brain specimens and 13 spinal cord specimens. By using both brain and spinal cord, 30 animals representing 8 species were diagnosed as rabid by FA, and 218, representing 11 species, were negative. There was 100% agreement between two procedures with FA as the criterion. This study showed that in cases where the usual examination is precluded due to brain destruction, the spinal cord procedure offers an equally reliable alternate method of diagnosis.