Epidemiological and bacterial profile of childhood meningitis in Tunisia.

The worldwide burden of disease of bacterial meningitis remains high, despite the decreasing incidence following introduction of routine vaccination campaigns.The aim of our study was to evaluate the epidemiological and bacteriological profile of paediatric bacterial meningitis (BM) in Tunisian children, during the period 2003-2019, following the implementation of Haemophilus influenzae type b (Hib) vaccine (April 2011) and before 10-valent pneumoccocal conjugate vaccine (PCV10) introduction to the childhood immunization program.All bacteriologically confirmed cases of BM admitted to children's hospital of Tunis were recorded (January 2003 to April 2019). Serogroups of Neisseria meningitidis (Nm) and serotypes of Streptococcus pneumoniae (Sp) and H. influenzae (Hi) and antibiotic resistance were determined using conventional and molecular methods.Among 388 cases, the most frequent species were Sp (51.3%), followed by Nm (27.5%) and Hi (16.8%). We observed a significant decrease in Hi BM rate during the conjugated Hib vaccine use period (P < 0.0001). The main pneumococcal serotypes were 14, 19F, 6B, 23F and 19A and the serotype coverage of PCV10, PCV13, PCV15 and PCV20 was 71.3 and 78.8%, 79.4 and 81.9% respectively. The most frequent Nm serogroup was B (83.1%). Most Hi strains were of serotype b (86.9%). High levels of resistance were found: Sp and Nm to penicillin (respectively 60.1 and 80%) and Hi to ampicillin (42.6%). All meningococcal and Hi isolates were susceptible to third-generation cephalosporins and 7.2% of pneumococcal strains had decreased susceptibility to these antibiotics.The Hib conjugate vaccine decreased the rate of BM. Sp dominated the aetiology of BM in children in Tunisia. Conjugate vaccines introducing decreases not only BM cases but also antimicrobial resistance.

Community-acquired pleuropneumonia in children: Bacteriological and therapeutic challenges.

Background Community-acquired pleuropneumonia (CPP) is a common complication of pneumonia in children. It is serious given its high morbidity and significant mortality. Aim To study clinical and paraclinical features of CPP in children and to establish a common therapeutic strategy. Methods Our retrospective study included patients who were hospitalized for CPP between 2004 and 2012. All data were collected from patients' medical files. Statistical analysis was made by Epi-Info 6. Results One hundred and sixty four patients were registered. The mean age was 32 months (15 days - 14.5 years). The hospital incidence of CPP doubled between 2004 and 2012. The symptomatology was dominated by fever (93.9%), cough (56.7%) and dyspnea (48.1%). The pleural effusion was frequently moderately abundant and loculated. Pleural sample, performed in 53.6% of cases, was the most beneficial bacteriological examination (p=10-6 ). The bacteriological confirmation was attained in 44.5% of cases with the predominance of Staphylococcus aureus (59%) followed by Streptococcus pneumoniae (26%). The S. aureus occurred basically in most young infants (p=0.04) and was responsible for the most severe cases (p=0.01). The CPP management included heterogeneous intravenous antibiotics associated with a pleural drainage in 40% of cases. The quarter of our patients were transferred to an intensive care unit. Six patients died. Conclusion The bacteriological confirmation is difficult. Pleural aspiration is the key tool. S. aureus is the first microorganism followed by S. pneumoniae. A therapeutic strategy is proposed based on large spectrum intravenous antibiotics. The pleural drainage indication is limited.

The diagnosis of pertussis: which method to choose?

Despite the introduction of routine vaccination against pertussis for more than a half century, leading to a drastic decline in the number of reported cases, pertussis continues to be an important respiratory disease afflicting unvaccinated infants and previously vaccinated children as well as adults in whom immunity has waned. The diagnosis of pertussis is challenging and accurate laboratory identification of Bordetella infections remains problematic. Common laboratory diagnostic methods used for pertussis diagnosis include culture, direct-fluorescent-antibody testing (DFA), serology and polymerase chain reaction (PCR). Culture of Bordetella pertussis is highly specific but fastidious and has limited sensitivity. DFA provides a much more rapid result, but has the disadvantage of poor sensitivity and specificity. Serology is not useful in infants. In older persons, it is hampered by the limitations of paired sera and it provides mainly a retrospective diagnosis. Such limitations of conventional diagnosis testing have led to the development of PCR assays. Notwithstanding its lack of standardization, PCR has been found to be more sensitive and more specific than other methods. In this report, we aimed to review current knowledge about the available diagnostic methods and tests that accurately diagnose pertussis.

High genotypic diversity of Rhinoviruses obtained from Tunisian children with severe acute respiratory infection.

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.

Epidemiological study of bacterial meningitis in Tunisian children, beyond neonatal age, using molecular methods: 2014-2017.

BACKGROUND: Since the 1990s, the epidemiology of bacterial meningitis worldwide has changed thanks to vaccination. In Tunisia, the main causative pathogens were Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae serotype b (Hib). Only Hib vaccination was available during our study period. OBJECTIVES: We performed a laboratory case report based-study of suspected bacterial meningitis in Northern Tunisia from January 2014 to June 2017. METHODS: CSF samples obtained from children beyond neonatal age with suspicion of meningitis were tested by two real time PCRs, targeting pneumococcus, meningococcus and Hib, and conventional methods. RESULTS: Using real-time PCR, 63 were positive including ten supplementary cases compared to conventional methods. A general decrease of bacterial meningitis cases was demonstrated comparing to previous data. Pneumococcus was predominant (69.84%) followed by meningococcus (28.57%) and Hib (1.59%). The main serotypes were 14, 19F, 6B and 23F for pneumococcus and serogroup B for meningococcus. Most cases occurred during cold season and children under one year were the most affected by bacterial meningitis. CONCLUSION: Our study suggests the predominance of pneumococcal cases. It may provide valuable data on meningitis epidemiology before the introduction of pneumococcal vaccine, which may be useful for future evaluation.

Genome characteristics of Bordetella pertussis isolates from Tunisia.

The recent increase in pertussis cases observed in some countries may have several causes, including the evolution of Bordetella pertussis populations towards escape of vaccine-induced immunity. Most genomic studies of B. pertussis isolates performed so far are from countries that use acellular vaccines. The objective was to analyse genomic sequences of isolates collected during the 2014 whooping cough epidemic in Tunisia, a country where whole-cell vaccines are used. Ten Tunisian isolates and four vaccine strains were sequenced and compared to 169 isolates from countries where acellular vaccines are used. Phylogenetic analysis showed that Tunisian isolates are diverse, demonstrating a multi-strain 2014 epidemic peak, and are intermixed with those circulating in other world regions, showing inter-country transmission. Consistently, Tunisian isolates have antigen variant composition observed in other world regions. No pertactin-deficient strain was observed. The Tunisian B. pertussis population appears to be largely connected with populations from other countries.

Seroprevalence of pertussis among healthcare workers: A cross-sectional study from Tunisia.

This cross-sectional study aimed to assess pertussis seroprevalence among healthy healthcare workers (HCW) of the Children's Hospital of Tunis, Tunisia. During the study period, 236 blood samples were obtained to determine HCW exposure to pertussis. Concentrations of immunoglobulin G (IgG) to pertussis toxin (PT) were measured using a commercial enzyme-linked immunosorbent assay. Cut-offs values used were 40 and 100 IU/ml, respectively indicative of an infection within the last year and a current/recent infection. Overall, seropositivity rate was 11.4% (95% CI 7.4-15.5) and 2.5% (95% CI 0.5-4.6) of ELISA results were indicative of a current infection. Seroprevalence was significantly most important in nurses (p = 0.03) and in participants aged 21-31y (p = 0.009). Our study confirmed that pertussis is circulating in hospital settings and affecting Tunisian HCW, in close contact with infants. Therefore, a booster dose of acellular pertussis vaccine needs to be considered.

Pertussis epidemiology in Tunisian infants and children and characterization of Bordetella pertussis isolates: results of a 9-year surveillance study, 2007 to 2016.

PURPOSE: Pertussis remains a public health concern in most countries. Our study aimed to prospectively explore the epidemiology of pertussis in the Tunis area of Tunisia between 2007 and 2016, and to characterize the virulence-associated genes of the collected Bordetella pertussis isolates. METHODOLOGY: Infants and children hospitalized at the Children's Hospital of Tunis, Tunisia, between 2007 and 2016 for suspicion of pertussis were enrolled in the study. Culture and real-time PCR (qPCR) assays targeting IS481, IS1001, recA, H-IS1001 and ptxP were used to confirm the pertussis diagnosis. Phenotypic and genotypic characterization of recovered isolates was performed.Results/Key findings. A total of 1844 children were included in the study. Overall, 306 children (16.6 %) with Bordetella infection were confirmed by qPCR. Among them, 265 (86.6 %) were confirmed as having B. pertussis (IS481+, ptxP+, H-IS1001-), 18 (5.9 %) as having Bordetella parapertussis (IS481-, IS1001+) and 11 (3.6 %) as having Bordetella spp. (IS481+, ptxP-, H-IS1001-). No Bordetella holmesii (IS481+, IS1001-, H-IS1001+) was identified. The estimated pertussis incidence in the Tunis area was 134/100 000 in children aged less than 5 years. Two epidemic peaks were observed in 2009 and 2014. Ten B. pertussis isolates were cultured and characterized. Deficiency in pertactin expression was not observed, and genotyping of the isolates revealed a predominant allelic profile: ptxP3-ptxA1-prn2-fim2-1-fim3-2. CONCLUSION: This study demonstrated that pertussis is still present as a cyclical disease in Tunisia, despite high primo-vaccination coverage with a pertussis whole-cell vaccine. The predominant genotype of Tunisian B. pertussis isolates is similar to isolates circulating in countries using the acellular vaccine.

Molecular diagnosis of bacterial meningitis by multiplex real time PCR in Tunisian children.

INTRODUCTION: Bacterial meningitis is a medical emergency requiring a fast and reliable diagnosis. Molecular methods such as real-time PCR (rt-PCR) offer an attractive alternative. Thus, this study aims to establish multiplex rt-PCRs detecting N. meningitidis, S. pneumoniae and H. influenzae b from cerebrospinal fluid in Tunisian children beyond neonatal age. METHODOLOGY: Using bioinformatic tools and experimentation, we validated the specificity and optimal criteria of PCRs for primers and probes of plyA (S. pneumoniae), ctrA and sodC (N. meningitidis) and bexA genes (H. influenzae b). We performed one multiplex RT-PCR for detection of S. pneumoniae and N. meningitidis targeting plyA and ctrA, sodC genes respectively, simultaneously with a singleplex RT-PCR for H. influenzae b. The sensitivity and specificity of our methods were assessed. Then, we tested our methods for 122 CSF samples collected from suspected meningitis cases between 2014 and 2016 in Bechir Hamza Children's Hospital of Tunis. RESULTS: Our results have shown the sensitivity of the designed PCRs was up to 10-4 DNA dilution and the specificity was 100%. PCR evaluation has shown 51 positive samples: 38 of pneumococcal cases, 12 meningococcal cases, 1 case of H. influenzae b with 8.57% and 50% of supplementary positive cases rates respectively. CONCLUSIONS: Our assay proved to be very sensitive, specific and rapid for bacterial meningitis diagnosis. In the recent context of Hib vaccination, the possibility of detecting S. pneumoniae and N. meningitidis separately constitute an attractive opportunity. Nevertheless, simultaneous detection of Hib remains relevant in specific clinical context and for epidemiologic study.

[Management of purpura fulminans apropos of 21 cases: diagnostic delay and therapeutic problems]. / Prise en charge du purpura fulminans a propos de 21 cas: retard diagnostique et problemes therapeutiques.

AIM: To evaluate the diagnostic delay and therapeutic insufficiencies delay before the transfer in ICU of the children admitted in the ICU of the children's hospital of Tunis with a purpura fulminans (PF). METHODS: A retrospective, descriptive study, of children with PF referred between January 2000 and January 2006 to a the paediatric intensive care unit (PICU) of the children's hospital of Tunis. The PF diagnosis was retained in any child presenting a feverish purpura and circulatory insufficiency signs. The optimal diagnostic and therapeutic charge taking was defined in three levels: parental, the first line doctors, and the hospital doctors. The symptoms' duration and the various treatments which were lavished to the patients were taken from the medical observations of the patients transferred in our PICU. RESULTS: Twenty one observations were collected. Twelve patients (57.1%) were addressed by a doctor exerting in a dispensary or by a free practicing doctor, 5 patients (23.8%) were transferred from a regional hospital and 4 children (19.1%) directly consulted the children hospital of Tunis urgencies delayed parental recognition occured in 11 children. The PF diagnosis was not evoked by the first line doctor in 62%. Eleven (52.4%) of the children with meningococcal disease were seen but not admitted by a doctor in the 48 hours before admission. Apart from 2 patients (9.5%) who were hospitalized in reanimation directly of the urgencies, all the other patients forwarded by a general pediatry service. In general pediatry, the PF diagnosis was not evoked in 3 cases (15.8%), 31.6% of patients had unnecessary a lumbar punctures and shock was not recognised or treated in 26.3%. Twelve patients (52.2%) died. The duration of hospitalization in general pediatry is significantly higher among deceased patients (5.5 +/- 6.6 hours) than among the surviving patients (2.6 +/- 1.5 hours); p < 0.05. CONCLUSION: Suboptimal treatement in PF is due to failure of parents, general practioners and hospital doctors to recognise specific features of the illness. Improvement in outcome could be achieved by public education and better training of clinicians in recognition, resuscitation, and stabilisation of seriously ill children.

Molecular Characteristics of Erythromycin-Resistant Streptococcus pyogenes Strains Isolated from Children Patients in Tunis, Tunisia.

AIM: The aims of our study were to characterize phenotypically and genotypically erythromycin-resistant Streptococcus pyogenes or group A streptococci (ERGAS) isolates, to evaluate macrolide resistance and to analyze the association between emm types and virulence factors. Included in this study were all ERGAS strains isolated from 2000 to 2013 at the Children's hospital of Tunis. Antimicrobial susceptibility was performed according to the CA-SFM guidelines. Macrolide resistance genes were revealed by polymerase chain reaction (PCR) method. Virulence factor genes (pyrogenic exotoxin genes and superantigen gene) were detected by PCR, and the emm types were defined by the sequencing of the variable 5' end of the emm gene. RESULTS: Among the 289 GAS isolates collected, 15 (5.2%) were resistant to erythromycin; 7 of the strains were assigned to the cMLSB phenotype (46.6%); 5 harbored ermB gene alone (33.3%); and 2 strains coharbored ermB and mefA (13.3%). The remaining (53.4%) were assigned to the M phenotype and harbored the mefA gene. The frequency of detection of each toxin gene among ERGAS was 13.4% for speA (2 strains), 53.4% for speC (8 strains), and 13.4% for ssa (2 strains). Emm types 1, 58, 11, and 78 were the most frequent among ERGAS strains. The distribution of the cMLSB and M phenotypes changed over the period of investigation with a decrement of cMLSB phenotype and ermB gene that predominated between 2000 and 2006 and an increase of M phenotype and mefA gene between 2007 and 2013, but this difference was nonstatistically significant because of the low number of resistant strains. Emm types 1, 58, and 4 were only present among strains assigned to the M phenotype. However strains assigned to the cMLSB phenotype were associated to emm11, emm22, emm28, emm78, or emm76. There was diversity in emm distribution in ERGAS between the two study periods. There was diversity in emm distribution among ERGAS particularly in 2000-2006. Indeed, from 2000 to 2006, the 6 ERGAS belonged to 5 different emm types (22, 28, 76, 11, and 4), while between 2007 and 2013, seven among the nine ERGAS belonged to only 2 emm types 58 and 1. The speA gene was present only among emm1 isolates, and the ssa gene was associated with emm4 and emm78 types. All emm78, emm28, and emm11 strains harbored speC gene. CONCLUSIONS: Our study revealed a low frequency of ERGAS and few emm types were associated with these strains.

Meningococcal disease in the Middle East and Africa: Findings and updates from the Global Meningococcal Initiative.

The Global Meningococcal Initiative (GMI) has recently considered current issues in Middle Eastern and African countries, and produced two recommendations: (i) that vaccination of attendees should be considered for some types of mass-gathering events, as some countries mandate for the Hajj, and (ii) vaccination of people with human immunodeficiency virus should be used routinely, because of increased meningococcal disease (MD) risk. Differences exist between Middle Eastern and African countries regarding case and syndrome definitions, surveillance, and epidemiologic data gaps. Sentinel surveillance provides an overview of trends and prevalence of different capsular groups supporting vaccine selection and planning, whereas cost-effectiveness decisions require comprehensive disease burden data, ideally counting every case. Surveillance data showed importance of serogroup B MD in North Africa and serogroup W expansion in Turkey and South Africa. Success of MenAfriVac® in the African "meningitis belt" was reviewed; the GMI believes similar benefits may follow development of a low-cost meningococcal pentavalent vaccine, currently in phase 1 clinical trial, by 2022. The importance of carriage and herd protection for controlling invasive MD and the importance of advocacy and awareness campaigns were also highlighted.

[Phenotyping and antibiotic susceptibility's study of Neisseria meningitidis strains isolated at the "Hôpital d'Enfants" of Tunis]. / Typage phenotypique et etude de la sensibilite aux antibiotiques des souches de neisseria meningitidis isolees a l'Hopital d'Enfants de Tunis (mars 1998 - fevrier 2004).

A total of 23 invasive strains of Neisseria meningitidis were isolated between March 1998 and February 2004. 19 strains were recovered from cerebrospinal fluid (CSF) and 4 from blood. The majority of these strains were recovered from children with an age less to 4 years (86.9%). The antigenic formula'study (serogroup:serotype:serosubtype) of the strain's collection have shown there great diversity. The sero-group B was the most frequent (83%) followed by serogroup C (17%). The B:NT:NST phenotype was major among strains of the serogroup B and the C:4:P1-14 phenotype among strains of the serogroup C. No beta-lactamase activity was detected. 30.4% of the strains were of diminished susceptibility to penicillin G (CM190 = 0.38 Ig/ml). No resistance to amoxicillin (CMI90 = 0.19 microg/ml), to cefotaxime (CMI90 = 0.016 microg/ml) and to rifampin (CMI90-0.125 microg/ml) was detected; whereas 8.7% of strains-were resistant to chloramphenicol (CMI90=2 Ig/ml) and 65.2% to spiramycin.

[Epidemiology of osteomyelitis and arthritis in infants]. / Epidémiologie des infections ostéo-articulaires du nourrisson.

A retrospective study realised over 10 years in the orthopaedic unit of the children's hospital of Tunis allowed to collect 206 cases of osteomyelitis and arthritis in infant (3 months--3 years old). In 74.6% of the cases, infection involved the joint. There is a single focus of the infection in 92.6% of the cases, more often at the lower limbs. The pathogen has been isolated in 33% of the cases. Staphylococcus aureus (52 %) is the more frequent pathogen, especially in osteomyelitis. Enterobateria (16%), Streptococcus (17.7%) (Streptococcus pneumonia: 10.7%), and Hemophylus influenzea (5.3%) were often isolated in arthritis.

[Value of reagent strips in screening urinary infection in children]. / Intérêt des bandelettes réactives dans le dépistage de l'infection urinaire chez l'enfant.

The aim of this study is to specify the role of rapid tests in the screening of childhood urinary tract infection. During the period between july to december 1998, 572 urinary samples were collected from pediatric out-patient in Hôpital d'Enfants de Tunis and aged from 1 month to 15 years. Only 75 samples (12.5%) were culture positive. The predictive value of leucocytes or nitrites test was 97.2%. These results allowed the use of rapid test in the screening of urinary tract infection in children. However, if clinical symptoms are present, the culture of urine must be associated to the rapid test.

[Epidemiologic profile of Haemophilus influenzae infection in Tunisia]. / Profil épidémiologique des infections à H. influenzae en Tunisie.

Haemophilus influenzae, a commensal bacteria, is frequently incriminated in broncho--pulmonary surinfections and severe diseases as meningitis, pneumonia and septic arthritis, particularly in young children. A multicenter study was conducted to establish the epidemiological profile of Haemophilus influenzae diseases, to determine the rate of antibiotics resistance for guide therapeutic and preventive strategies. The identification was based on the requirements for X and V factors, and the serotype b determined by agglutination. The betalactamase production was done by nitrocefin test. Antimicrobial susceptibility testing was determined on Muller Hinton chocolate agar with isovitalex. During the two year period, (January 1998 December 1999), 192 isolates of H. Influenzae were collected, 61% were recovered from invasive infections (44 meningitis, 8 bacteremia, 2 arthritis). The serotype b was identified in 55.7% of cases, 67.3% were invasive strains. 24.5% of isolates were producing betalactamase particularly invasive serotype b strains. All isolates of H. influenzae were susceptible to cefotaxim and to ofloxacin. Resistance rates to other antibiotics were: erythromycin 56.2%, tetracyclin 10.3%, rifampin 12%, chloramphénicol 1%, cotrimoxazole 16.5%, 11.5% amikacin and 20% gentamicin. The incidence of meningitis remained frequent in our country, involving the introduction of the vaccination in official calendar. Nevertheless, the surveillance of H. influenzae invasives infections and the serotyping of isolates were necessary to evaluate the impact of the immunization.

[Antibiotic sensitivity of Streptococcus pneumoniae in Tunisia: results of a multicenter study (1998-1999)]. / Sensibilité aux antibiotiques de Streptococcus pneumoniae en Tunisie: résultats d'une étude multicentrique (1998-1999).

We report the results of a multicenter tunisian study, performed over a two-year period (1998-1999), to determine the susceptibility pattern of Streptococcus pneumoniae in our country. A total of 146 S. pneumoniae were collected during the study period. 76 were recovered from adults and 70 from children. 53% of isolates have decreased susceptibility to penicillin, 24% with low level resistance, and 11% with high level resistance. Amoxicillin and cefotaxime decreased susceptibility rates were: 12% (low level resistance exclusively). and 14% (10% with low level resistance and 4% with high level resistance) respectively. Strains isolated from children, showed higher resistance to b lactams than those isolated from adults. Resistance rates to other antibiotics were as follow: erythromycin 28%, choramphenicol 14%, cyclins 23%, thrimethoprim-sulfamethoxazole 28% and rifampin 1%. No vancomycin resistant strain was found. The acquire resistance rates of Streptococcus pneumoniae in Tunisia are worrying, essentially for penicillin and erythomycin. Amoxicillin and cefotaxime have conserved a good activity.

[Pseudomonas aeruginosa: a multicentric study of antibiotic resistance (1999-2000)]. / Pseudomonas aeruginosa: étude multicentrique de la résistance aux antibiotiques (1999-2000).

A retrospective multicentric study was carried out over a period of 2 years (1999-2000). 2659 strains of Pseudomonas aeruginosa were collected from 4 university hospitals (Charles Nicolle Hospital, Pediatric Hospital and National Centre of Bone Marrow Transplantation in Tunis, Habib Bourguiba Hospital in Sfax). Epidemiological profile and antibiotic susceptibility were analysed. All bacteria were identified by conventional methods and antibiotic susceptibility tests were performed according to CA-SFM guidelines. The strains were recovered essentially from surgical wards (33%) and intensive care units (22%). Pseudomonas aeruginosa was isolated mainly from pus (36%), urine (32%) and respiratory samples (18%). 25% of strains were resistant to ticarcilline, 18% to cefsulodine, 9% to ceftazidime, 14% to imipenem and amikacin and 25% to ciprofloxacin. Moreover, the resistance rates varied from hospital to hospital and from unit to another. The resistant strains were isolated particularly from urology and intensive care units: respectively 62% and 39% for ticarcilline; 26% and 13% for ceftazidime. The acquired resistance to b-lactams seems largely due to penicillinase production. The frequency of resistance to ceftazidime was the lowest and seems associated to chromosomal cephalosporinase over production.

[Antibiotic resistance among E. coli isolates from urinary tract infections (1999-2000): a multicenter study]. / Sensibilite aux antibiotiques des souches urinaires d'E. coli (1999-2000): resultats d'une étude multicentrique.

E. coli is the most frequently isolate species in community as well as in nosocomial acquired urinary tract infections (UTI). Trimethoprim-sulfamethoxazole (TMP-SMX), is commonly used as empiric treatment for managing uncomplicated UTI whereas the rate of resistance to amoxicilline is increasing. A multicentric retrospective study was conducted from January 1st 1999 to December 31st 2000 to evaluate the prevalence of E. coli isolates from UTI and to guide empiric therapies. Among 6994 urinary isolates, 62.6% were resistant to amoxicilline, this rate fell to 33.6% when amoxicilline was associated to clavulanic acide, 2.7% were producing extended spectrum b-lactamases (BLSE), higher than reported in France and USA. 37.3% were resistant to TMP-SMX. The high prevalence of antimicrobial resistance among UTI E. coli isolates emphasizes the necessity to review the empiric therapies. Fluoroquinolones can be considered as an alternative therapy according to their excellent tissue penetration and their wide spectrum of activity.

Trend of plasmid-mediated quinolone resistance genes at the Children's Hospital in Tunisia.

The prevalence of plasmid-mediated quinolone resistance genes [qnr, aac(6')-Ib-cr and qepA] was sought among Enterobacteriaceae strains obtained from the Children's Hospital of Tunis (Tunisia). Non-duplicate isolates (n = 278) with resistance to extended-spectrum cephalosporins and collected in 2003, 2007, 2008 and 2009 were screened for qnr genes. Forty (14.4 %) isolates were qnr positive and were screened for the presence of the aac(6')-Ib-cr and qepA genes. qnrB was detected in 21 Klebsiella pneumoniae, 11 Escherichia coli and 6 Enterobacter cloacae isolates. Sequence analysis of the qnrB amplicons revealed variants including 24 qnrB1, 11 qnrB2 and 3 qnrB6. qnrS (qnrS1 allele) was detected only in K. pneumoniae isolates, either alone (two isolates) or with the qnrB gene (one isolate). The qnrA, qnrC and qnrD genes were not found in any of the 278 isolates. No qnr-positive isolates carried the qepA gene. Pyrosequencing results showed that aac(6')-Ib-cr, a variant of the aac(6')-Ib gene, was present in 31 qnr-positive isolates (21 K. pneumoniae isolates, seven Escherichia coli isolates and three Enterobacter cloacae isolates). aac(6')-Ib was also found either alone (two isolates) or in association with aac(6')-Ib-cr (one isolate). Of the 40 qnr-positive isolates, 92.5, 82.5, 57.5, 85 and 82.5 % were non-susceptible to nalidixic acid, ciprofloxacin, levofloxacin, ofloxacin and norfloxacin, respectively, and all were extended-spectrum ß-lactamase producers. Random amplified polymorphic DNA-PCR typing of these isolates showed 16, 8 and 5 different genotypes in K. pneumoniae, Escherichia coli and Enterobacter cloacae isolates, respectively. Our study highlights the high prevalence of qnr in association with aac(6')-Ib-cr among Enterobacteriaceae isolates, even from children, who are patients not overtreated with quinolones.