Introduction: Pertussis outbreaks continue to occur in many countries despite high vaccination coverage. Under-diagnosed cases in adolescents and adults may result in increased transmission to infants, who are at risk of severe pertussis. Additional measures to protect both groups should be considered. Methodology: Nasopharyngeal samples and sera were collected from patients and household contacts with clinically suspected pertussis. Diagnoses were confirmed by culture, real-time polymerase chain reaction (PCR), and serology. Bordetella pertussis isolates were characterized by antimicrobial sensitivity and fimbrial serotyping. Results: Of 392 participants, 134/248 patients (54%) and 66/144 contacts (45.8%) had confirmed pertussis infections. B. parapertussis was not detected. All B. pertussis isolates were sensitive to the antibiotics tested, and all expressed the Fim3, not the Fim2, fimbrial serotype. Most patients (81.2%) were <6 months (51.8% of whom were <3 months) of age; 77.6% were unvaccinated, and most positive contacts were mothers 20-40 years of age. Conclusions: Despite high vaccination coverage, pertussis is circulating in Algeria. Most infections occur in unvaccinated infants <6 months of age, with mothers as the main source of infection. An adolescent/adult booster should be considered. Adoption of sensitive and specific laboratory tests would improve pertussis diagnosis and surveillance.

Introduction: The aim of this study was to investigate the drug-resistance and the molecular characterization of carbapenemases, ESBL, and aminoglycoside-modifying enzymes among Acinetobacter baumannii clinical isolates in Algerian hospitals. Methodology: A total of 92 A. baumannii isolates were collected between 2012 and 2016. Antimicrobial susceptibility testings were performed for β-lactams, aminoglycosides, fluoroquinolones, trimethoprim-sulfamethoxazole, rifampicin and colistin. The phenotypic characterization of β-lactamases was investigated. For 30 randomly targeted strains, the carriage of the carbapenemases, ESBL and aminoglycoside-modifying enzymes -encoding genes was determined by PCR. Sequencing was carried out for carbapenemases and ESBL genes. Results: Most of the 92 isolates studied were recovered from hospitalized patients (93.5%) and were mainly from intensive care units (51.1%) and orthopedics (19.6%). The strains were collected primarily from low respiratory tract (33.7%), wounds (23.9%) and urine (16.3%). Multidrug-resistant A. baumannii strains were prevalent (96.7%). High rates of resistance were observed for almost all antibiotics tested (>70%) excluding rifampicin (7.6%) and colistin (5.4%). For the five colistin-resistant strains, MICs ranged between 4 and 128 µg/mL. Positive MBL (83.7%) and ESBL (23.9%) strains were identified. Regarding β-lactams, the blaNDM and both blaSHV and blaCTX-M1 genes were detected in five and two strains respectively. Sequencing of the genes revealed the presence of blaNDM-1, blaCTX-M-15, and blaSHV-33. For aminoglycosides, aac(6’)-Ib, ant(2’’)-I and aph(3’)-VI genes were detected in three, seven and six strains respectively. Conclusions: Here, we report the first co-occurrence of extended-spectrum β-lactamases SHV-33 and CTX-M-15, the carbapenemase NDM-1 and the emergence of colistin-resistant A. baumannii in Algerian hospitals.

Introduction: vancomycin-resistant Enterococcus faecium (VREfm) is a major public health problem worldwide. The aim of our study was to determine the microbiological, epidemiological and molecular characteristics of VREfm isolated in north-central, eastern and western Algeria. Methodology: a collection of 48 VREfm isolated from September 2010 to April 2017 in several Algerian hospitals were studied. Minimum inhibitory concentrations (MICs) were determined by E-test method according to CLSI guidelines. the detection of van genotype of all strains was performed by PCR. Clonal relationship of five VREfm targeted by region were characterized using multilocus sequence typing (MLST). Results: All isolates have multidrug-resistance (MDR) and were resistant to at least five classes of antibiotics; however, all were susceptible to tigecycline and daptomycin with MIC50 at 0.094 µg/mL and 2 µg/mL respectively. All strains belonged to vanA genotype and have high level of resistance to vancomycin and teicoplanin. MLST revealed two sequence types (STs): ST80 (from the four regions of Algeria) and ST789, both belonging to the former hospital-adapted clonal complex CC17. Conclusions: the alarming dissemination of MDR E. faecium vanA and the ST80 in several regions of Algeria suggest a clonal spread of VREfm strains, which urgently require implementation of adequate infection control measures.

ObjectivesTo determine immune responses to selected vaccine-preventable communicable diseases: pertussis, diphtheria and Haemophilus influenzae type b (Hib1) in Algerian toddlers and preschool children after primary vaccination and first booster, recruited from three local healthcare facilities in Northwestern Algiers.MethodsThe information of demographic characteristics and vaccination status were collected for each subject by questionnaire. Specific antibody levels and Hib antibody avidity were determined using commercial ELISA kits.ResultsA total of eighty-one subjects aged between 19 and 55 months were studied. Almost all subjects were fully protected against diphtheria (76/81; 93.83%; 95% CI2: 86.35–97.33) and invasive Hib disease (29/30; 96.67%; 95% CI: 83.33–99.41), while only 20/78 (25.64%; 95% CI: 17.26–36.31) had anti-PT3 (pertussis toxin) antibody levels above 25 IU/ml. A significant decrease of anti-PT antibody levels was observed until the age of 36 months (p = 0.02). GMTs4 (geometric mean titers) of anti-PT antibodies were low, but remain significantly higher in children ≤36 months of age (p = 0.02). Both GMT and rates of ≥0.15 μg/ml, ≥1 μg/ml, and ≥5 μg/ml titers were significantly higher in Hib-vaccinated subjects (p < 0.01). Relative Hib-avidity index (≥50%) and GMAI5 (geometric mean avidity index) were high in both Hib-vaccinated and -unvaccinated groups.ConclusionsAs shown in the present study, young children were fully protected against diphtheria and Hib, but showed low immunity to pertussis. Further sero-epidemiological studies including a large number of subjects with a wider range of age are needed to explore the immunity level in older children, adolescents and adults.

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Introduction: The aim of this study was to investigate the presence of carbapenemase-producing Enterobacteriaceae (CPE) in Algerian hospitals and to characterize the molecular types of carbapenemases found. Methodology: During a four years study lasting between 2012 and 2015, 81 strains of Enterobacteriaceae with reduced susceptibility to carbapenems were collected from different hospitals. Carbapenemase genes were detected by PCR. Multi locus sequence typing was used to study genetic relationships between carbapenemase- producing Klebsiella pneumoniae isolates. Results: Among 56 confirmed CPE, blaOXA-48 was detected in 98.21% of isolates. Two isolates co-expressed NDM, and a single one was only an NDM producer. The strains displayed various susceptibility patterns to antibiotics with variable levels of resistance to carbapenems. Multilocus sequence typing (MLST) revealed the presence of multiple sequence types in circulation. Conclusions: This report highlights the wide distribution of several clones of OXA-48-producing Enterobacteriaceae in Algeria. Urgent action should be taken to avoid epidemic situations.

We describe the emergence of plasmid-mediated colistin resistance mcr-1 in a clinical isolate of Escherichia coli ST19. The strain was isolated from a urine sample of a 75-year-old male patient. The identification was carried out by an automated system. The antibiogram was performed according to CLSI recommendations. The colistin MIC was determined by broth micro-dilution according to CA-SFM/EUCAST criteria. The detection of mcr-1 was carried out by immunochromatographic test and PCR mcr-1. Genetic transfers and determination of the plasmid incompatibility group were made. The ST was carried out by MLST using the Pasteur scheme.The strain has a high-level penicillinase resistance phenotype. It was susceptible to amikacin and resistant to gentamicin, tobramycin, fluoroquinolones, tetracycline, chloramphenicol, and cotrimoxazole. The strain was resistant to colistin (MIC ꞊ 4 μg/ml).The genetic transfer is given a colistin-resistant transconjugant. The plasmid carrying mcr-1 gene belongs to the incompatibility group IncHI2.The strain belongs to ST19.