Case report of an abdominal wet gangrene caused by Acidaminococcus.

The Acidaminococcus genus is a part of the normal flora in gastrointestinal tract. It is a strictly anaerob Gram-negative coccus that is rarely pathogenic. We report the case of a 58-year-old man, who presented to surgery department A of the Charles Nicolle hospital, complaining of a wide inflammatory lesion in the anterior abdominal wall evolving for two weeks. Patient's anamnestic data included smoking, hypertension, and diabetes mellitus with poor compliance. The patient underwent flattening with excision of necrotic tissues and surgical drainage using a DELBET blade. Empirical antibiotic therapy with imipenem 1gx3/d, teicoplanin 400 mg 1 inj x2/d and gentamicin 400 mg 1 inj/d was administered pending bacteriological results. The bacteriological examination of a sample of necrotic tissue, after 72 h of incubation at 37 °C in anaerobic atmosphere, was able to detect a Gram-negative coccus, that the VITEK2 ANC system identified as Actinomyces canis with an accuracy of 80%. Whole genome sequencing was subsequently performed, that identified Acidaminococcus sp. AM33-14BH and demonstrated the following resistance genes: cfxa, tet(X) and tet(Q). An antibiogram for anaerobes was performed showing that the strain was resistant to amoxicillin but sensitive to amoxicillin-clavulanic acid, piperacillin-tazobactam, ertapenem, imipenem, meropenem and rifampin. Patient's condition improved after treatment with imipenem for 2 weeks, followed by oral amoxicillin-clavulanic acid for 16 days.This work highlights the role of molecular biology in the diagnosis of infections caused by anaerobes. Although the Vitek 2 ANC card provides rapid and acceptable identification of the most common anaerobic bacteria, improvements are needed for the identification of bacteria in the genera Acidaminococcus and Actinomyces.

Characteristics and prognostic factors of COVID-19 among infected cases: a nationwide Tunisian analysis.

BACKGROUND: The outbreak of coronavirus disease (COVID-19) continues to constitute an international public health concern. Few data are available on the duration and prognostic factors of the disease. We aimed to study the recovery time among a Tunisian cohort of COVID-19 confirmed patients and identify the prognostic factors. METHODS: A retrospective, nationwide study was conducted from March 2 to May 8, 2020, recruiting all patients who were diagnosed with COVID-19, by RT-PCR methods, in Tunisia. Data were collected via phone call interview. Kaplan-Meir Methods and Cox proportional hazards regression models were, respectively, used to study the recovery time and estimate its prognostic factors. RESULTS: One thousand and thirty patients with COVID-19 (aged 43.2 ± 18.2 years, 526 female (51.1%)) were enrolled. Among them 141 (14.8%) were healthcare professionals. Out of 173 patients (17.8%) admitted to the hospital, 47 were admitted in an intensive care unit. Among 827 patients who didn't require specialized care, 55.5% were self-isolated at home, while the rest were in specialized centers. Six hundred and two patients were symptomatic. A total of 634 (61.6%) patients have recovered and 45 (4.4%) patients died. The median duration of illness was estimated to be 31 days (95% CI: [29-32]). Older age (HR = 0.66, CI:[0.46-0.96], P = 0.031) and symptoms (HR = 0.61, CI:[0.43-0.81], P = 0.021) were independently associated with a delay in recovery time. Being a healthcare professional (HR = 1.52, CI: [1.10-2.08], P = 0.011) and patients in home isolation compared to isolation centers (HR = 2.99, CI: [1.85-4.83], P < 10¯3) were independently associated with faster recovery time. CONCLUSION: The duration of illness was estimated to be 1 month. However, this long estimated duration of illness may not equate to infectiousness. A particular attention must to be paid to elderly and symptomatic patients with closer monitoring.

Multidrug resistance and high virulence genotype in uropathogenic Escherichia coli due to diffusion of ST131 clonal group producing CTX-M-15: an emerging problem in a Tunisian hospital.

A collection of 201 Escherichia coli strains isolated from urine of patients in a Tunisian hospital between January 2006 and July 2008 was studied. Microbial identification was done by conventional methods, and antibiotic susceptibility with disk diffusion method was performed according to the Clinical Laboratory and Standards Institute guidelines. Detection of extended-spectrum beta-lactamase (ESBL) was performed by double-disk synergy test (DDST) and identification was done by PCR and sequencing. ESBL-producing isolates were subjected to molecular typing by random amplified polymorphic DNA (RAPD) and ST131 detection by PCR. Four phylogenetic groups (A, B1, B2 and D), 18 virulence genes and CTX-M group were individualized using PCR. Statistical analysis was done by Pearson χ2 test and Mann-Whitney U test. The strains were recovered primarily from urology (28%), maternity (19%) and medicine (16%) wards. Antibiotic resistance rates were ampicilin (72.1%), nalidixic acid (41.8%), ciprofloxacin (38.8%), gentamicin (23.9%) and cefotaxime (17.4%). Thirty-one of cefotaxime-resistant isolates (n = 35) had a positive DDST and harboured bla CTX-M-15 gene. Twenty of them (64.5%) belonged to the ST131 clone and showed the same RAPD DNA profile. Ciprofloxacin- and cotrimoxazole-susceptible isolates were significantly associated with phylogenetic group B2, whereas isolates that were resistant to these molecules were associated with B1 and D phylogenetic groups, respectively. Virulence genes were significantly more frequent among ciprofloxacin- and cotrimoxazole-susceptible strains than those resistant to these antibiotics. However, CXT-M-15-producing isolates were associated with many virulence genes. Isolates concomitantly susceptible to the three antimicrobials agents (ciprofloxacin, cefotaxime and cotrimoxazole) were significantly associated with group B2 and high virulence score, whereas isolates with resistance patterns especially those including resistance to ciprofloxacin belonged predominantly to B1 phylogroup and haboured few virulence genes. The emergence of virulent and multidrug-resistant E. coli is a concerning development that deserves close attention in our institution.