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Rhinoviruses (RV) are a major cause of Severe Acute Respiratory Infection (SARI) in children, with high genotypic diversity in different regions. However, RV type diversity remains unknown in several regions of the world. In this study, the genetic variability of the frequently circulating RV types in Northern Tunisia was investigated, using phylogenetic and phylogeographic analyses with a specific focus on the most frequent RV types: RV-A101 and RV-C45. This study concerned 13 RV types frequently circulating in Northern Tunisia. They were obtained from respiratory samples collected in 271 pediatric SARI cases, between September 2015 and November 2017. A total of 37 RV VP4-VP2 sequences, selected among a total of 49 generated sequences, was compared to 359 sequences from different regions of the world. Evolutionary analysis of RV-A101 and RV-C45 showed high genetic relationship between different Tunisian strains and Malaysian strains. RV-A101 and C45 progenitor viruses’ dates were estimated in 1981 and 1995, respectively. Since the early 2000s, the two types had a wide spread throughout the world. Phylogenetic analyses of other frequently circulating strains showed significant homology of Tunisian strains from the same epidemic period, in contrast with earlier strains. The genetic relatedness of RV-A101 and RV-C45 might result from an introduction of viruses from different clades followed by local dissemination rather than a local persistence of an endemic clades along seasons. International traffic may play a key role in the spread of RV-A101, RV-C45, and other RVs.

Introduction: Rhinoviruses (HRV) are among the leading causes of Severe Acute Respiratory Infection (SARI). Their burden and genetic diversity vary from one region to another and little is known in Northern African regions. This study describes epidemiological patterns and genotypic diversity of HRV in SARI cases during a two and half year’s study, in Northern Tunisia. Methodology: A total of 271 SARI cases, admitted into the Pediatric Intensive Care Unit of Bechir Hamza Children's Hospital in Tunis, were collected between September 2015 and December 2017. The investigation concerned 104 samples positive for HRV and/or HEV (Human Enterovirus) obtained among these cases. Specific HRV and HEV detections were assessed by real-time PCRs. The HRV molecular typing was based on the VP4-VP2 genomic region analyses. Results: Among the viral SARI cases, 33.5% and 12.3% were positive for HRV and HEV respectively. Molecular investigations showed high prevalence of HRV-A (63.3%) followed by HRV-C (30.6%) and HRV-B (6.1%) and high genotypic diversity with 27 types. HRV cases were mostly detected in toddlers younger than 6 months. A total of 16 cases (28%) were found with bacterial and/or viral co-infection. HRV-C infection and HRV-A with bacterial co-infection were associated with complicated infection. Some of the detected types showed a continuous circulation or turnover during an extended period. HRV-A101 and HRV-C45 were the most frequently detected types. Conclusions: This study revealed, for the first time, the high HRV diversity in Tunisia, a North-African region. Specific phylogenetic investigations may help to evaluate their diversity and to trace their spread and epidemiological origin.

Rhinoviruses (RV) are a major cause of Severe Acute Respiratory Infection (SARI) in children, with high genotypic diversity in different regions. However, RV type diversity remains unknown in several regions of the world. In this study, the genetic variability of the frequently circulating RV types in Northern Tunisia was investigated, using phylogenetic and phylogeographic analyses with a specific focus on the most frequent RV types: RV-A101 and RV-C45. This study concerned 13 RV types frequently circulating in Northern Tunisia. They were obtained from respiratory samples collected in 271 pediatric SARI cases, between September 2015 and November 2017. A total of 37 RV VP4-VP2 sequences, selected among a total of 49 generated sequences, was compared to 359 sequences from different regions of the world. Evolutionary analysis of RV-A101 and RV-C45 showed high genetic relationship between different Tunisian strains and Malaysian strains. RV-A101 and C45 progenitor viruses' dates were estimated in 1981 and 1995, respectively. Since the early 2000s, the two types had a wide spread throughout the world. Phylogenetic analyses of other frequently circulating strains showed significant homology of Tunisian strains from the same epidemic period, in contrast with earlier strains. The genetic relatedness of RV-A101 and RV-C45 might result from an introduction of viruses from different clades followed by local dissemination rather than a local persistence of an endemic clades along seasons. International traffic may play a key role in the spread of RV-A101, RV-C45, and other RVs.

This study was conducted to evaluate the rate of fecal carriage of Gram-negative bacilli (GNB) resistant to third-generation cephalosporins (third GC) in patients hospitalized in the intensive care unit (ICU) of Charles Nicolle Hospital of Tunis and to identify the enzymatic mechanisms involved. From February to April 2014, rectal swabs were collected from all patients (n = 38) at admission and once weekly thereafter to identify acquisition. They were cultured on desoxycholate-lactose-agar plates supplemented with cefotaxime (2 mg/L). The rate of fecal carriage of GNB resistant to third GC was 0% (0/38) at admission and the acquisition rate was 45.16% (14/31). Nineteen GNB resistant to C3G were collected from 14 patients. The major species collected were Acinetobacter baumannii (n = 5), Klebsiella pneumoniae (n = 5), and Enterobacter cloacae (n = 5). Thirteen extended-spectrum β-lactamase (ESBL) producing GNB were found; CTX-M-15 (n = 10) and CTX-M-14 (n = 1) among Enterobacteriacae and GES-12 (n = 2) among A. baumannii. Ten strains were carbapenem resistant. OXA-48 (n = 4) and NDM-1 (n = 1) were detected among Enterobacteriacae and OXA-23 (n = 5), and GES-11 (n = 1) were detected in A. baumannii. Gene encoding the ACT-16 AmpC-type-β-lactamase was detected in two isolates. All Escherichia coli isolates were assigned to group B2. Among virulence genes, prevalence of fimH, fuyA, ompT, pai, and usp were highest observed in all E. coli isolates. Among K. pneumoniae mrkD and entB were the most frequent (n = 5) followed by ybtS (n = 4) and kfu (n = 2). This study revealed a high prevalence of fecal carriage of multidrug-resistant GNB, including ESBLs, carbapenemases, and cephalosporinases producing bacteria in patients hospitalized in ICU.

Eighty-two nonduplicated ampicillin-resistant Enterococcus faecium (AREF) isolates from clinical infections at the Charles Nicolle Hospital of Tunisia were investigated. They were collected from January 2001 to December 2009. Genetic relationship between them was studied using pulsed-field gel electrophoresis. The amino acid sequence difference variations of the C-terminal part of penicillin-binding protein 5 (PBP5) versus levels of expressed mRNA were investigated by polymerase chain reaction (PCR), sequencing, and real-time PCR quantification of (PBP5), respectively. No β-lactamase activity was detected and none of our strains showed resistance to glycopeptides, which retain their therapeutic efficiency against enterococcal infections in our hospital. Pattern analysis of the strains revealed six main clones disseminating in different wards. Sequence data revealed the existence of 19 different plp5 alleles with a difference in 16 amino acid positions spanning from residue 414 to 632. Each allele presented at least five amino acid substitutions (His-470→Gln, Asn-496→Lys, Ala-499→Thr, Glu-525→Asp, and Glu-629→Val). No correlation between amino acid sequence polymorphism of PBP5 and levels of ampicillin resistance was detected. The levels of plp5 mRNA expression varied between strains and did not always correlate with levels of ampicillin resistance in clinical AREF.

This study was conducted to investigate the molecular epidemiology of extended spectrum β-lactamase (ESBL)-producing Escherichia coli in community-acquired (urinary tract) infections (CA-UTI) in Tunisia. Between January 2007 and December 2009, 15 E. coli isolates were collected at the laboratory of microbiology of Charles Nicolle Hospital of Tunis. Microbial identification was done with conventional methods. Antibiotic susceptibility was determined by disk diffusion method and ESBL detection was done with double-disk synergy test. ESBL typing was performed by polymerase chain reaction (PCR) and sequencing. Phylogenetic groups, virulence factors, and sequence type (ST)131 were determined by PCR. Genetic relatedness between strains was examined by pulsed-field gel electrophoresis (PFGE) after restriction with XbaI. The prevalence of ESBL-producing E. coli in CA-UTI was 0.046%. The majority of isolates were multidrug resistant. ESBL types were CTX-M-15 (n=13) and SHV-12 (n=2). The most common phylogenetic group was B2 (n=11) and virulence score was greater than or equal to 9 in nine strains. PFGE revealed 12 clusters. The majority of isolates (n=14) belonged to ST131 clone and 11 of them were CTX-M producers. In conclusion, this is the first detailed documentation of CA-ESBLs producing E. coli in Tunisia. Of particular concern is the emergence in our community of the highly diffusing CTX-M-15-B2-ST131 E. coli clone, which requires strengthening surveillance measures to countervail this emergent public health problem.

This study was conducted to investigate the molecular epidemiology of extended spectrum β-lactamase (ESBL)-producing Escherichia coli in community-acquired (urinary tract) infections (CA-UTI) in Tunisia. Between January 2007 and December 2009, 15 E. coli isolates were collected at the laboratory of microbiology of Charles Nicolle Hospital of Tunis. Microbial identification was done with conventional methods. Antibiotic susceptibility was determined by disk diffusion method and ESBL detection was done with double-disk synergy test. ESBL typing was performed by polymerase chain reaction (PCR) and sequencing. Phylogenetic groups, virulence factors, and sequence type (ST)131 were determined by PCR. Genetic relatedness between strains was examined by pulsed-field gel electrophoresis (PFGE) after restriction with XbaI. The prevalence of ESBL-producing E. coli in CA-UTI was 0.046%. The majority of isolates were multidrug resistant. ESBL types were CTX-M-15 (n=13) and SHV-12 (n=2). The most common phylogenetic group was B2 (n=11) and virulence score was greater than or equal to 9 in nine strains. PFGE revealed 12 clusters. The majority of isolates (n=14) belonged to ST131 clone and 11 of them were CTX-M producers. In conclusion, this is the first detailed documentation of CA-ESBLs producing E. coli in Tunisia. Of particular concern is the emergence in our community of the highly diffusing CTX-M-15-B2-ST131 E. coli clone, which requires strengthening surveillance measures to countervail this emergent public health problem.[PUBLICATION ABSTRACT]

In 2009, out of the 66 nonrepetitive Enterobacter cloacae collected at Charles Nicolle hospital in Tunisia, 44 were extended spectrum β-lactamase (ESBL) producers. The aim of the current study was to detect and characterize the genes encoding the ESBLs including blaTEM, blaSHV, and blaCTX-M groups by polymerase chain reaction and sequencing. Pulsed-field gel electrophoresis (PFGE) analysis was used to determine the genetic relatedness between isolates. All strains were susceptible to carbapenems. They were resistant to fluoroquinolones, gentamicin, tobramycin, and trimethoprim+sulfamethoxazole but variably resistant to netilmicin, amikacin, and tetracyclines. Sequence analysis of the polymerase chain reaction products revealed the presence of blaCTX-M-15 (39 strains), blaSHV-12 (6 strains), and blaSHV-27 (1 strain). The coexistence of two ESBLs was observed in two isolates harboring, respectively, SHV-12+CTX-M-15 and SHV-27+CTX-M-15. PFGE revealed 36 unrelated profiles. Diffusion of E. cloacae producing CTX-M-15 ESBL in our hospital is the consequence of dissemination of identical or related plasmids harboring the CTX-M-15 gene.

An unusual case of a juxtabronchial lymphoepithelial cyst in an HIV-positive child with post-obstructive pneumonia is presented. The pathogenesis and similarity with parotid lymphoepithelial cysts is discussed.

The standardization of fifth generation (5G) communications has been completed, and the 5G network should be commercially launched in 2020. As a result, the visioning and planning of 6G communications has begun, with an aim to provide communication services for the future demands of the 2030s. Here, we provide a vision for 6G that could serve as a research guide in the post-5G era. We suggest that human-centric mobile communications will still be the most important application of 6G and the 6G network should be human centric. Thus, high security, secrecy and privacy should be key features of 6G and should be given particular attention by the wireless research community. To support this vision, we provide a systematic framework in which potential application scenarios of 6G are anticipated and subdivided. We subsequently define key potential features of 6G and discuss the required communication technologies. We also explore the issues beyond communication technologies that could hamper research and deployment of 6G. This Perspective provides a vision for sixth generation (6G) communications in which human-centric mobile communications are considered the most important application, and high security, secrecy and privacy are its key features.