Determination of In Vitro Antiprotease, Antimicrobial, and Antibiofilm Activities of <em>Beta vulgaris</em> var. cicla against Multidrug-Resistant Strains of <em>Pseudomonas aeruginosa</em>

Antibiotic resistance of Pseudomonas aeruginosa causes many infectious diseases and it is agreat. So, the aim of the present work was to assess the antibacterial, antibiofilm activity of Beta vulgaris extracts against resistance bacteria P. aeruginosa that were clinically isolated and tested for their antiprotease potential. Result showed that methanol extract exhibited important antiprotease activity against Trypsin, Savinase, and digestive proteases of blue crab with percentage of inhibition of 94.66, 91.39, and 86.41%, respectively. It showed also important antibiofilm activities against multidrug-resistant P. aeruginosa with inhibition values upper than 80% with a concentration of 4MIC. Our investigation delivered that Beta vulgaris might be possible source of natural antienzymatic, antimicrobial, and antibiofilm agents

Detection of metallo-beta-lactamase producing Pseudomonas aeruginosa using a modified IMP-lysate assay

Since the increasing prevalence of carbapenem-resistant Pseudomonas aeruginosa spp., accurate detection of metallo-β-lactamase (MBL) such as blaVIM type enzyme producing isolates became very important. However, phenotypic MBL detection methods previously reported are not highly sensitive or highly specific. This study aimed to evaluate the performance of a modified IMP-lysate test, the doubledisk- synergy-test (DDST) and the combined-disk-test (CDT) for detecting MBL blaVIM gene in P. aeruginosa. The reference technique was PCR molecular test. The study used 12 blaVIM2 producer isolates, 13 MBL-negative controls which included 4 imipenem-susceptible strains and 9 imipenemresistant strains harbouring blaSHV-2a genes collected from two Tunisian hospitals and P. aeruginosa ATCC27853 and P. aeruginosa COL-1 as negative and positive controls respectively. CDT showed 100% of sensitivity. The highest level of specificity was shown by IMP-lysate test (76.92%). To evaluate efficiencies of methods, the study noted that the highest Youden Index (YI) was shown by IMP-lysate method (0.7), followed by DDST (0.6) than CDT (0.2). Since MBL-Etest and PCR were expensive and not adaptable for extension use in clinical microbiology laboratories, a modified IMP-lysate MBL hydrolytic activity can be chosen by laboratories with limited resources as an inexpensive, simple, and accurate test to detect . P. aeruginosa producing blaVIM enzyme.Key words: Metallo-beta-lactamase, VIM, phenotypic detection, pseudomonas aeruginosa

Genotyping of Methicillin Resistant Staphylococcus aureus Strains Isolated from Hospitalized Children

Community associated methicillin resistant Staphylococcus aureus (CA-MRSA) is an emerging pathogen increasingly reported to cause skin and soft tissue infections for children. The emergence of highly virulencet CA-MRSA strains in the immunodeficiency of young children seemed to be the basic explanation of the increased incidence of CA-MRSA infections among this population. The subjects of this study were 8 patients hospitalized in the Pediatric Department at the University Hospital of Monastir. The patients were young children (aged from 12 days to 18 months) who were suffering from MRSA skin infections; two of them had the infections within 72 h of their admission. The isolates were classified as community isolates as they all carried the staphylococcal cassette chromosome mec (SCCmec) IV and pvl genes. Epidemiological techniques, pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST), were applied to investigate CA-MRSA strains. Analysis of molecular data revealed that MRSA strains were related according to PFGE patterns and they belonged to a single clone ST80. Antimicrobial susceptibility tests showed that all strains were resistant to kanamycin and 2 strains were resistant to erythromycin

Biological activities of Peganum harmala leaves

Ethyl acetate, chloroform, butanol and methanol extracts of the leaves of Peganum harmala were tested for antibacterial, antioxidant and antiviral activities. The antibacterial activity was evaluated by the determination of minimum inhibitory concentration (MIC) using the solid medium technique. The antiviral activity was evaluated against human cytomegalovirus (HCMV) strain AD-169 (ATCC Ref. VR 538) and Coxsackie B virus type 3 (CoxB-3) using diagnostic method ‘shell-vial’ culture. The antioxidant activity was evaluated using ammonium thiocyanate method. Among tested extracts, methanol and chloroform extracts displayed a higher antibacterial activity against gram-positive than gram-negative bacteria. The methanol extract demonstrated the highest antioxidant activity and good antiviral activity against HCMV.Key words: Peganum harmala, antimicrobial, antiviral, antioxidant, activities, leave

Molecular characterization of enterovirus detected in cerebrospinal fluid and wastewater samples in Monastir, Tunisia, 2014-2017

Background: Enteroviruses (EVs) are considered the main causative agents responsible for aseptic meningitis worldwide. This study was conducted in the Monastir region of Tunisia in order to know the prevalence of EV infections in children with meningitis symptoms. Detected EV types were compared to those identified in wastewater samples. Methods: Two hundred CSF samples collected from hospitalized patients suspected of having aseptic meningitis for an EV infection between May 2014 and May 2017 and 80 wastewater samples collected in the same time-period were analyzed. EV detection and genotyping were performed using PCR methods followed by sequencing. Phylogenetic analyses in the 3'-VP1 region were also carried-out. Results: EVs were detected in 12% (24/200) CSF and in 35% (28/80) wastewater samples. EV genotyping was reached in 50% (12/24) CSF-positive samples and in 64% (18/28) sewage. Most frequent types detected in CSF were CVB3, E-30 and E-9 (25% each). In wastewater samples, the same EVs were identified, but also other types non-detected in CSF samples, such as E-17,CVA9 and CVB1 from EV species B, and EV-A71 and CVA8 from EV-A, suggesting their likely lower pathogenicity. Phylogenetic analysis showed that within the same type, different strains circulate in Tunisia. For some of the EV types such as E-9, E-11 or CVB3, the same strains were detected in CSF and wastewater samples. Conclusions: Epidemiological studies are important for the surveillance of the EV infections and to better understand the emergence of certain types and variants.Y. Rmadi was supported by the grant of the Ministry of Higher Education and Research of Tunisia.S

Multidrug-resistant Acinetobacter baumannii strains carrying the blaOxA-23 and the blaGES-11 genes in a neonatology center in Tunisia

Multidrug-resistant and difficult-to-treat Acinetobacter baumannii may be responsible for nosocomial infections. The production of carbapenem-hydrolyzing class D β-lactamases (CHDLs) and extended-spectrum β-lactamase (ESBLs) of the GES type possessing a carbapenemase activity has been increasingly reported worldwide in A. baumannii. The aim of this study was to analyze the resistance mechanisms of two carbapenem resistant A. baumannii clinical isolates recovered in a neonatology center in the center-east of Tunisia.Two carbapenem resistant A. baumannii isolates were recovered. The first isolate co-harbored the blaGES-11 ESBL gene and the blaOxA-23 CHDL gene. Analyses of the genetic location indicated that the blaGES-11 gene was plasmid located (Gr6). However, the blaOxA-23 gene was located on the chromosome. The second strain had only the blaOxA-23 CHDL gene, which was plasmid located.This study showed the first description of the GES-type β-lactamase in A. baumannii in Tunisia

Rotavirus Strain Diversity in the Centre Coast of Tunisia from 2000 through 2003

An epidemiological survey investigating rotavirus infection in children was undertaken in the coastal region of Tunisia from January 2000 through September 2003. A total of 309 fecal specimens were screened by enzyme-linked immunosorbent assay and latex agglutination assay for the presence of group A rotavirus antigen. The detection rate was 26.2%. Rotavirus outbreaks showed a temperature-dependant pattern (P= .026) but no significant association with rainfall. Rotavirus strains isolated were analyzed by RNA polyacrylamide gel electrophoresis and were characterized antigenically by monoclonal antibodies to the VP6 subgroup. Eight RNA electropherotypes were identified, with 3 long and 5 short different RNA profiles. Among VP6 typeable strains, all isolates with a long electrophoretic pattern carried the subgroup II specificity, whereas those with a short profile belonged to subgroup I. In total, 48 rotavirus-positive samples were analyzed for G and P typing by reverse-transcription polymerase chain reaction. A total of 8 different G and P combinations were found: G1P[8] (35.7%), G1P[6] (21.4%), G2P[4] (4.8%), G3P[4] (4.8%), G4P[6] (4.8%), G8P[8] (4.8%), G3P[8] (2.3%), and G4P[8] (2.3%). Mixed infections were detected in 19.1% of stool samples. The emergence in Tunisia of unconventional types, such as G8VP7 specificity, highlights the need for a continual survey of the uncommon strains in North Afric

A four-year survey (2011-2014) of West Nile virus infection in humans, mosquitoes and birds, including the 2012 meningoencephalitis outbreak in Tunisia

A West Nile virus (WNV) outbreak occurred in Tunisia between mid-July and December 2012. To assess the epidemiological features of the WNV transmission cycle, human cerebrospinal fluid samples from patients with suspected cases (n = 79), Culex pipiens mosquitoes (n = 583) and serum specimens from domestic and migratory birds (n = 70) were collected for 4 years (2011-2014) in the Tunisian Sahel region. Viral testing was performed by polymerase chain reaction (PCR). The WNV genome was detected in 7 patients (8.8%), 4 Culex pipiens pools, and a domestic mallard (Anas platyrhynchos). All PCR-positive samples were from the Monastir region. Phylogenetic analysis revealed that two different WNV strain groups circulated, and isolates from the reservoir (bird), vector (Culex pipiens), and dead-end hosts (humans) were closely related. The Monastir region is a hot-spot for WNV infection, and the reiterative presence of WNV over the years has increased the risk of viral reemergence in Tunisia, which highlights the need for more enhanced and effective WNV surveillance in humans with public awareness campaigns strengthened by monitoring mosquitoes and maintaining avian surveillance for early detection of WNV circulation