Bothrops atrox and Bothrops lanceolatus Venoms In Vitro Investigation: Composition, Procoagulant Effects, Co-Factor Dependency, and Correction Using Antivenoms

Bothrops venoms are rich in enzymes acting on platelets and coagulation. This action is dependent on two major co-factors, i.e., calcium and phospholipids, while antivenoms variably neutralize venom-related coagulopathy effects. Our aims were (i) to describe the composition of B. atrox and B. lanceolatus venoms; (ii) to study their activity on the whole blood using rotational thromboelastometry (ROTEM); (iii) to evaluate the contribution of calcium and phospholipids in their activity; and (iv) to compare the effectiveness of four antivenoms (Bothrofav™, Inoserp™ South America, Antivipmyn™ TRI, and PoliVal-ICP™) on the procoagulant activity of these two venoms. Venom composition was comparable. Both venoms exhibited hypercoagulant effects. B. lanceolatus venom was completely dependent on calcium but less dependent on phospholipids than B. atrox venom to induce in vitro coagulation. The four antivenoms neutralized the procoagulant activity of the two venoms; however, with quantitative differences. Bothrofav™ was more effective against both venoms than the three other antivenoms. The relatively similar venom-induced effects in vitro were unexpected considering the opposite clinical manifestations resulting from envenomation (i.e., systemic bleeding with B. atrox and thrombosis with B. lanceolatus). In vivo studies are warranted to better understand the pathophysiology of systemic bleeding and thrombosis associated with Bothrops bites.

Antibiotic susceptibility of cultivable microbiota from the oral cavity of captive Bothrops atrox and Bothrops lanceolatus: Implications for the treatment of snakebite-associated infections in the French departments of America

INTRODUCTION

Secondary infection is a frequent complication after bites by Bothrops atroxin French Guiana or B. lanceolatus in Martinique. Knowledge of the bacteria present in snake mouths is a valuable aid for determining probabilistic antibiotherapy after Bothrops bite. The objectives of this study were to describe the cultivable bacteria of the oral microbiota of the specimens of B. atrox and B. lanceolatus kept in captivity, and to study their susceptibility to antibiotics.

METHODS

Fifteen B. atrox and 15 B. lanceolatus were sampled. Bacterial cultures were performed and each morphotype on plates was identified using MALDI-TOF mass spectrometry. Antibiotic susceptibility was studied using the agar disk diffusion method, with possible determination of the MICs.

RESULTS

One hundred and twenty-two isolates were identified: 52 isolates and 13 species in B. atrox, 70 isolates and 23 species in B. lanceolatus. The main species were Providencia rettgeri, Morganella morganii, Pseudomonas aeruginosa, Staphylococcus xylosus, and Paeniclostridium sordellii (only in B. lanceolatus mouths). For B. atrox, 96% of isolates were susceptible to piperacillin/tazobactam, cefepime, imipenem and meropenem, 94% to ciprofloxacin and 76% to cefotaxime and ceftriaxone. For B. lanceolatus, 97% of isolates were susceptible to meropenem, 96% to cefepime, 93% to imipenem and piperacillin/tazobactam, 80% to ciprofloxacin, and 75% to cefotaxime and ceftriaxone. Many isolates were resistant towards amoxicillin/clavulanate.

CONCLUSION

Among currently recommended antibiotics, cefepime and piperacillin/tazobactam seem more suitable than cefotaxime or ceftriaxone in the event of a Bothrops bite. Ciprofloxacin may also be considered for B. atrox.

Chikungunya Outbreak in Country with Multiple Vectorborne Diseases, Djibouti, 2019-2020

During 2019-2020, a chikungunya outbreak occurred in Djibouti City, Djibouti, while dengue virus and malaria parasites were cocirculating. We used blotting paper to detect arbovirus emergence and confirm that it is a robust method for detecting and monitoring arbovirus outbreaks remotely.

Tocilizumab-treated convalescent COVID-19 patients retain the cross-neutralization potential against SARS-CoV-2 variants

Although tocilizumab treatment in severe and critical coronavirus disease 2019 (COVID-19) patients has proven its efficacy at the clinical level, there is little evidence supporting the effect of short-term use of interleukin-6 receptor blocking therapy on the B cell sub-populations and the cross-neutralization of SARS-CoV-2 variants in convalescent COVID-19 patients. We performed immunological profiling of 69 tocilizumab-treated and non-treated convalescent COVID-19 patients in total. We observed that SARS-CoV-2-specific IgG1 titers depended on disease severity but not on tocilizumab treatment. The plasma of both treated and non-treated patients infected with the ancestral variant exhibit strong neutralizing activity against the ancestral virus and the Alpha, Beta, and Delta variants of SARS-CoV-2, whereas the Gamma and Omicron viruses were less sensitive to seroneutralization. Overall, we observed that, despite the clinical benefits of short-term tocilizumab therapy in modifying the cytokine storm associated with COVID-19 infections, there were no modifications in the robustness of B cell and IgG responses to Spike antigens.

[Severe cytomegalovirus-associated protein losing gastropathy in an immunocompetent adult]

INTRODUCTION

Clinical expression of cytomegalovirus (CMV) infection is numerous and depends on the immune status of the host. In immunocompromised patients, CMV disease corresponds to reactivation of the virus with tissue damage responsible for significant morbidity and mortality. In immunocompetent adults, primary CMV infection is usually asymptomatic but may rarely result in severe organ damage.

OBSERVATION

We report the case of a 28-year-old man, considered immunocompetent and without medical history, presenting with a primary CMV infection revealed by a severe protein-losing gastroenteropathy (serum albumin level: 18.9g/L). The CT scan showed a gastro-duodeno-jejuno-ileitis pattern. Upper intestinal endoscopy revealed diffuse ulcerated and congestive gastritis predominantly in the fundus. Histological analysis of the biopsies showed no viral inclusion and no immunohistochemical staining reaction, but a high viral load (5.61 log). Treatment was symptomatic associated with anticoagulation due to the major hypoalbuminemia. The patient slowly recovered, and normal clinical examination and blood tests were observed two months after the onset of symptoms.

CONCLUSION

Severe CMV organ involvement in the immunocompetent patient is very rare but potentially serious. Digestive involvement complicated by exudative enteropathy is possible. Evolution is usually favorable without the need for antiviral treatment.

Abbott® ID NOW™ COVID-19 rapid molecular assay versus Hologic® Panther Aptima™ SARS-CoV-2 assay in nasopharyngeal specimens: results from 1-year retrospective study in an emergency department

We compared ID Now™ and Hologic® Panther Aptima™ for the detection of SARS-COV-2. ID Now™ showed a positive and negative percent agreement of 86.9% and 99.7% respectively. This facilitates faster clinical decision-making, along with the rapid implementation of infection control measures, and improvement of patient flow in the emergency department toward inpatient wards.

COVID-19 critique et anticorps anti-Interféron : série de 11 cas

Introduction

La survenue de formes sévères ou critiques de COVID-19, avec nécessité d’une hospitalisation en réanimation, est associée à la présence d’anticorps anti-Interféron de classe I dans environ 10 % des cas [1]. Ces anticorps identifiés dans le contexte de la COVID-19 bloquent les molécules d’interféron (IFN) et expliqueraient chez ces patients, la survenue d’une atteinte grave de COVID-19, avec une absence d’élimination précoce du virus SARS-CoV-2. Ainsi, il s’agirait d’une forme de déficit immunitaire, acquis, dirigé contre le virus SARS-CoV-2 mais aussi potentiellement contre d’autres virus. Les caractéristiques cliniques, biologiques et morphologiques des patients présentant ces anticorps n’ont pas été décrites précisément, l’évolution des patients n’est pas connue.

Patients et méthodes

Une recherche d’anticorps anti-Interféron a été réalisée chez des patients ayant été pris en charge en réanimation à l’hôpital Bégin, à l’hôpital Avicenne et à l’hôpital Foch pour une COVID-19. La présence d’anticorps anti-IFNalpha2 et anti-IFNomega étaient recherchée par test ELISA puis confirmée par un test fonctionnel d’inhibition de la phosphorylation de STAT1. Les caractéristiques cliniques des patients ont été relevées à partir des dossiers médicaux. Un suivi médical a été organisé afin de suivre leur évolution sur le plan clinique, biologique et morphologique.

Résultats

Onze patients ont été identifiés. Il s’agissait de 11 hommes. L’âge médian au diagnostic était de 60 ans (min 36 - max 80). Parmi les autres facteurs de risques de COVID-19 grave classiquement identifiés, on retrouvait chez eux, du diabète pour 1 patient, de l’hypertension artérielle pour 6 patients et de l’obésité (IMC > 30 kg/m²) pour 5 patients. L’IMC médian était de 29,8 kg/m² (min 24 - max 32,8). Il n’était pas noté d’antécédent remarquable, notamment pas d’argument pour un déficit immunitaire, pas d’endocrinopathie auto-immune. On retrouvait 1 BPCO, 2 asthmes, 1 coronaropathie et 1 valve aortique mécanique. Au diagnostic de COVID-19, les signes cliniques initiaux habituels de l’infection étaient retrouvés : asthénie (n = 11), fièvre (n= 10), toux (n = 5). Deux patients présentaient des diarrhées et 2 de l’insuffisance rénale aiguë, modérée. Chez 2 patients, on notait une embolie pulmonaire sur le scanner initial. L’évolution était marquée par une aggravation justifiant une admission en réanimation après une médiane de 7 jours (min 3 - max 12), pour une forme sévère chez 2 patients avec au maximum une oxygénothérapie au masque à haute concentration jusqu’à 15L/min pour 1 patient et 4L/min pour 1 autre. Une forme critique survenait chez 9 patients, avec recours à une intubation oro-trachéale pour ventilation mécanique pour 7 cas, une oxygénothérapie nasale à haut débit (OPTIFLOW) était suffisante dans 2 cas. Des pneumopathies bactériennes documentées nécessitaient une antibiothérapie spécifique dans 6 cas. Dans 10 cas, des traitements à visée spécifique du COVID-19 étaient entrepris : corticothérapie (n = 4), hydroxychloroquine (n = 4), lopinavir/ritonavir (n = 3) et tocilizumab (n = 2). En raison du développement d’un SDRA sévère, des séances d’optimisation de l’oxygénothérapie par décubitus ventral étaient entreprises chez 5 patients, avec nécessité d’un recours à une ECMO véno-veineuse pour le jeune patient de 36 ans. Afin d’éliminer les Ac antiIFN, ce dernier a également bénéficié avec succès de 3 séances d’échanges plasmatiques. Au total, 9 patients ont survécu, la durée médiane d’hospitalisaiton en réanimation était de 16 jours (min 2 - max 31). Les 2 décès sont intervenus après limitation thérapeutique pour SDRA réfractaire. Avec un suivi médian de 4,2 mois (min 1 - max 11,2), on note une bonne évolution chez l’ensemble des patients survivants, aucune réinfection n’a été observée et une régression quasi complète des lésions pulmonaires scanographiques (n = 4/5) était retrouvée à 3 mois. Lors du dernier bilan réalisé, il n’était pas constaté d’anomalie de la NFS (n = 7/8), ni syndrome inflammatoire (n = 6/7) et le taux d’immunoglobulines était normal (4/4).

Conclusion

Cette série de cas donne une première description des patients ayant présenté une forme critique de COVID-19 avec Ac anti-IFN de classe I. En dehors de la faible prévalence de comorbidités, il ne semble pas y avoir de phénotype clinique particulier chez cette population en dehors de la prédominance masculine.

Performances, feasibility and acceptability of nasopharyngeal swab, saliva and oral-self sampling swab for the detection of severe acute respiratory syndrome coronavirus 2

Molecular diagnosis on nasopharyngeal swabs (NPS) is the current standard for COVID-19 diagnosis, but saliva may be an alternative specimen to facilitate access to diagnosis. We compared analytic performances, feasibility and acceptability of NPS, saliva, and oral-self sampling swab for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). A prospective, multicenter study was conducted in military hospitals in France among adult outpatients attending COVID-19 diagnosis centers or hospitalized patients. For each patient, all samples were obtained and analyzed simultaneously with RT-PCR or transcription-mediated amplification method. Clinical signs, feasibility, and acceptability for each type of sample were collected. A total of 1220 patients were included, corresponding to 1205 NPS and saliva and 771 OS. Compared to NPS, the sensitivity, specificity, and kappa coefficient for tests performed on saliva were 87.8% (95% CI 83.3–92.3), 97.1% (95% CI 96.1–98.1), and 0.84 (95% CI 0.80–0.88). Analytical performances were better in symptomatic patients. Ct values were significantly lower in NPS than saliva. For OS, sensitivity was estimated to be 61.1% (95% CI 52.7–69.4) and Kappa coefficient to be 0.69 (95% CI 0.62–0.76). OS was the technique preferred by the patients (44.3%) before saliva (42.4%) and NPS (13.4%). Instructions were perceived as simple by patients (> 90%) for saliva and OS. Finally, the painful nature was estimated to be 0.9 for OS, on a scale from 0 to 10, and to be 5.3 for NPS. Performances of OS are not sufficient. Saliva is an acceptable alternative to NPS for symptomatic patient but the process required additional steps to fluidize the sample.

Molecular epidemiological of extended-spectrum β-lactamase producing Escherichia coli isolated in Djibouti

INTRODUCTION

While the molecular epidemiology of extended-spectrum-b-lactamase (ESBL)-producing E. coli is well known in Europe due to effective surveillance networks and substantial literature, data for Africa are less available, especially in Djibouti.

METHODOLOGY

We studied 31 isolates of ESBL-producing E. coli from Djibouti and compared these molecular results with data available in Africa.

RESULTS

Susceptibility rates were 3.2% for ceftazidim, 48.4% for piperacillin-tazobactam, 90.3% for amikacine and 16.1% for ofloxacin. No isolate showed resistance to carbapenems or colistin. 30 E. coli (96.8%) were positive to blaCTX-M-15, 1 (3.2%) to blaCTX-M-14  and 10 (32.3%) to narrow-broad-spectrum blaTEM. No blaSHV were detected. Fluoroquinolone resistance analysis showed that 30 ofloxacin-resistant E. coli had the mutation Ser-83->Leu on the gyrA gene. 24 E. coli (77.4%) harboured the plasmid-borne aac(6 ')-Ib-cr gene. No E. coli carried the genes qnrA, qnrB and qepA. 10 isolates (32.3%) belonging to the ST131 clone. The plasmid incompatibility group most widely represented in our collection was IncFIA/IB/II.

CONCLUSIONS

There is no major difference with African epidemiology. In particular, we notice the international diffusion of specific clonal group ST131.

Salmonella enterica serovar enteritidis peritonitis with spontaneous intestinal perforation in an immunocompetent patient

Few data reported non-typhoidal Salmonella peritonitis in immunocompromised patients. We reported the case of a man without immunosuppression or predisposing factor, who developed Salmonella enterica serovar Enteritidis peritonitis with spontaneous intestinal perforation. After emergent surgery, the patient was transferred to intensive care unit (ICU) because of respiratory, renal and haemodynamic failures. When S. enterica serovar Enteritidis was identified, antibiotics were de-escalated for ceftriaxone and metronidazole for 5 days. No immunosuppression was found. Evolution was favourable, and the patient has been discharged from the ICU on day 8. The originality of this case arises from a perforation peritonitis secondary to S. enterica without any immunosuppression. In absence of non-Typhi Salmonella data, we treated this patient as a typhoid perforation: surgical treatment, antibiotic association and supportive care.

Microbiology of French military casualties repatriated from overseas for an open traumatic injury

BACKGROUND

This study aimed to describe the microbiological epidemiology of repatriated French soldiers with an open traumatic injury, and to measure the proportion of multidrug-resistant bacteria (MDRB).

METHODS

Retrospective study including all French soldiers repatriated in 2011 and 2012 in Parisian military hospitals for open traumatic injury. Results of clinical samples and MDRB screening were collected. The antibiotic susceptibility was assessed using the agar disk diffusion method. Characterization of resistance mechanisms was performed using PCR. Genotyping of extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) isolates was performed using rep-PCR.

RESULTS

A total of 139 patients were included; 70% of them were repatriated from Afghanistan. At admission, 24/88 were positive for MDRB (28%), mainly ESBL-E but no carbapenemase-producing Enterobacteriaceae and vancomycin-resistant Enterococcus faecium were identified. Forty-five patients had lesion sample collection, and 28/45 had a positive culture. The most frequently isolated pathogens were Enterobacter cloacae, Pseudomonas aeruginosa, and Escherichia coli. For eight patients, a MDRB was isolated from the wound, mainly ESBL-E (7/8) but also one methicillin-resistant Staphylococcus aureus and one imipenem-resistant Acinetobacter baumannii. Among ESBL-E, the PCR evidenced the high prevalence of CTX-M15 enzymes. Rep-PCR performed on the 23 ESBL-producing E. coli isolates highlighted numerous profiles.

CONCLUSIONS

Controlling the spread of ESBL-E is currently challenging for French Armed Forces. Despite any evidence of an epidemic clone, a high-level compliance with hygiene precautions is required throughout the chain of care to avoid cross contamination.

Clinical isolates of Escherichia coli solely resistant to mecillinam: prevalence and epidemiology

In routine susceptibility testing of Gram-negative bacteria, a particular resistance phenotype was observed: an Escherichia coli isolate from a urine sample exhibited resistance solely to mecillinam (MEC) but was fully susceptible to other β-lactam antibiotics (MEC-R-BL-S). The objectives as this study were to determine the prevalence of this phenotype and to describe the phenotype, molecular epidemiology and genetic background. Between 1 January 2014 and 31 January 2016, MEC-R-BL-S E. coli isolates from urine were collected and genes previously reported as mostly involved in MEC resistance were analysed. The genetic relatedness among isolates was investigated by repetitive element sequence-based PCR (rep-PCR) and multilocus sequence typing (MLST). Ten MEC-R-BL-S isolates were collected, accounting for 0.4% (10/2547) of all E. coli obtained from urine samples, 0.9% (10/1135) of ampicillin-susceptible E. coli isolates and 9.6% (10/104) of MEC-R E. coli isolates. The isolates appeared as small colonies with round morphology and had impaired fitness. The isolates were not clonal and belonged to various extraintestinal or commensal E. coli phylogroups. Mutations in the cysB gene were evidenced in all clinical isolates. In conclusion, microbiologists should be aware of these isolates with a particular susceptibility phenotype, which is not due to error in disk diffusion but is a real non-enzymatic antibiotic resistance pattern.

Peripherally Inserted Central Catheter-Related Infections in a Cohort of Hospitalized Adult Patients

PURPOSE

To determine the incidence and the risks factors of peripherally inserted central catheter (PICC)-related infectious complications.

MATERIALS AND METHODS

Medical charts of every in-patient that underwent a PICC insertion in our hospital between January 2010 and October 2013 were reviewed. All PICC-related infections were recorded and categorized as catheter-related bloodstream infections (CR-BSI), exit-site infections, and septic thrombophlebitis.

RESULTS

Nine hundred and twenty-three PICCs were placed in 644 unique patients, mostly male (68.3%) with a median age of 58 years. 31 (3.4%) PICC-related infections occurred during the study period corresponding to an infection rate of 1.64 per 1000 catheter-days. We observed 27 (87.1%) CR-BSI, corresponding to a rate of 1.43 per 1000 catheter-days, 3 (9.7%) septic thrombophlebitis, and 1 (3.2%) exit-site infection. Multivariate logistic regression analysis showed a higher PICC-related infection rate with chemotherapy (odds ratio (OR) 7.2-confidence interval (CI) 95% [1.77-29.5]), auto/allograft (OR 5.9-CI 95% [1.2-29.2]), and anti-coagulant therapy (OR 2.2-95% [1.4-12]).

CONCLUSION

Chemotherapy, auto/allograft, and anti-coagulant therapy are associated with an increased risk of developing PICC-related infections.

CLINICAL ADVANCE

Chemotherapy, auto/allograft, and anti-coagulant therapy are important predictors of PICC-associated infections. A careful assessment of these risk factors may be important for future success in preventing PICC-related infections.

Partition locus-based classification of selected plasmids in Klebsiella pneumoniae, Escherichia coli and Salmonella enterica spp.: an additional tool

The dissemination of antimicrobial resistance genes in Enterobacteriaceae has been largely attributed to plasmids, circular DNA molecules capable of autonomous replication. Whereas high-copy-number plasmids primarily rely on passive diffusion for plasmid maintenance, low-copy-number plasmids utilize so-called partition (par) systems. Plasmid partition relies on three structures, i.e. a centromere like DNA site, a centromere-binding protein and an ATPase or a GTPase motor protein for plasmid positioning. Identification and classification of plasmids is essential for tracing plasmids conferring drug resistance. PCR-based replicon typing is currently the standard method for plasmid identification but there are new classification schemes, especially the relaxase gene typing (PRaseT). Here we developed a multiplex PCR set targeting par loci found on the plasmids most frequently encountered in Enterobacteriaceae. This method, called "plasmid partition gene typing" (PAR-T), was validated with 136 transconjugants or transformants harboring various replicon types. The method was tested with 30 multidrug-resistant clinical isolates including Escherichia coli, Klebsiella pneumoniae and Salmonella enterica subsp. enterica carrying 1-4 replicons; all replicons were tested in parallel with PRaseT for comparison. Six multiplex PCRs and one simplex PCR including 18 pairs of primers recognized plasmids of groups IncA/C, FIA, FIB, FIC, FIIk, FII, HI1, HI2, I1, L/M, N, X. Our set of multiplex PCRs showed high specificity for the classification of resistance plasmids except for IncX replicons.

Cluster of zoonotic cutaneous leishmaniasis (Leishmania major) in European travelers returning from Turkmenistan

We report a cluster of cutaneous leishmaniasis due to Leishmania major in four immunocompetent travelers returning from Western Turkmenistan and having atypical and/or multiple lesions. Treatments with pentamidine or fluconazole were effective. Physicians should be aware that some virulent strains of L major currently circulate in Central Asia.

Effectiveness of latex agglutination slide test in the diagnosis of imported invasive amoebiasis in the emergency department

We compared a latex agglutination test (LAT) with enzyme-linked immunosorbent assay and indirect hemagglutination assay in the diagnosis of invasive amoebiasis. A retrospective biological records review has included 639 patients for whom these three serological tests were performed. The sensitivity of the LAT was 97.8% and the specificity was 97%.

Fabrication and superhydrophobic behavior of fluorinated microspheres

We describe the preparation of fluorinated microspheres by precipitation polymerization and their use to fabricate superhydrophobic surfaces. For that purpose, two different approaches have been employed. In the first approach, a fluorinated monomer (either 4-fluorostyrene or 2,3,4,5,6-pentafluorostyrene) was added to the initial mixture of monomers constituted by styrene (S) and divinylbenzene (DVB). The second approach is based on the encapsulation of a block copolymer, polystyrene-b-poly(2,3,4,5,6-pentafluorostyrene), during the polymerization of the monomers (S and DVB), thus enabling the formation of particles with perfluorinated chains instead of single functional groups at the interface. Both approaches led to narrow polydisperse particles with fluoro-functional groups at the interface as demonstrated by scanning electron microscopy (SEM), infrared (IR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). Surface array of particles obtained by simple solvent casting presented superhydrophobic behavior with contact angles of water droplets of ca. 160-165°.

Implication de la pharmacogénétique dans les traitements des cancers colorectaux

SCOPE

Clinical implications associated with polymorphisms in drug-metabolizing genes involved in the chemotherapy of colorectal cancers (5-flurorouracil, oxaliplatin and irinotecan) are reviewed.

CURRENT SITUATION AND SALIENT POINTS

Treatments of colorectal cancers have been greatly improved last years but patients respond differently to identical medication. Genetic polymorphisms are one of the major causes of these individual responses to drugs associated with sometimes severe adverse effects. Pharmacogenetics is based on all polymorphisms that determine genetic human diversity associated with variable response to anticancer drugs.

PERSPECTIVES

Morbidity and mortality related to toxicity or inefficacy of these drugs could be reduced by analyzing the pharmacogenetic profile of patients before treatment. Results should be integrated in protocols for monitoring and assessment the dosage of drugs.