Diarrhoeagenic Escherichia coli in mother-child Pairs in Ile-Ife, South Western Nigeria

BACKGROUND: Diarrhoeagenic Escherichia coli (DEC) pathotypes are among the most common bacterial causes of morbidity and mortality in young children. These pathogens are not sought routinely and capacity for their detection is limited in Africa. We investigated the distribution and dissemination of DEC in 126 children paired with their mothers in a Nigerian community. METHODS: A total of 861 E. coli were isolated from 126 children with diarrhoea and their mothers. Antimicrobial susceptibility of each isolate was determined by Kirby-Bauer disc diffusion technique. All the isolates were screened for DEC markers by multiplex PCR. Genetic relatedness of DEC strains was determined by flagellin typing and Insertion element 3 (IS3)-based PCR. RESULTS: DEC were identified from 35.7 % of individuals with the most common pathotype being shiga toxin-producing E. coli (42, 16.7 %). Identical pathotypes were found in 13 (10.3 %) of the mother-child pairs and in three of these strains from mothers and their children showed identical genetic signatures. Over 90 % of DEC isolates were resistant to ampicillin, sulphonamide, tetracycline, streptomycin or trimethoprim, but only 9 (7.2 %) were ciprofloxacin resistant CONCLUSION: The data suggest that healthy mothers are asymptomatic reservoirs of multiply-resistant strains that are pathogenic in their children and there are instances in which identical strains are found in mother-child pairs

Correction: Classes 1 and 2 integrons in faecal Escherichia coli strains isolated from mother-child pairs in Nigeria.

[This corrects the article DOI: 10.1371/journal.pone.0183383.]

Prolonged febrile illness due to CTX-M-15 extendedspectrum β-lactamase-producing <i>Klebsiella pneumoniae</i> infection in Nigeria

We report on an 8-year-old patient with septicaemia unresponsive to therapy for five weeks. Undetected, extended-spectrum β-lactamase (ESBL) production by the infecting Klebsiella strain was regarded as responsible for treatment failure. Intravenously administered imipenem during the sixth week led to sustained resolution of fever. Resource-limited hospitals can incur prohibitive costs from ESBL-producer infections because of diagnostic limitations and consequent treatment failure involving prolonged supportive therapy

Rapid evolution of fluoroquinolone-resistant Escherichia coli in Nigeria is temporally associated with fluoroquinolone use

Background: Antibiotic resistance has necessitated fluoroquinolone use but little is known about the selective forces and resistance trajectory in malaria-endemic settings, where selection from the antimalarial chloroquine for fluoroquinolone-resistant bacteria has been proposed. Methods: Antimicrobial resistance was studied in fecal Escherichia coli isolates in a Nigerian community. Quinolone-resistance determining regions of gyrA and parC were sequenced in nalidixic acid resistant strains and horizontally-transmitted quinolone-resistance genes were sought by PCR. Antimicrobial prescription practices were compared with antimicrobial resistance rates over a period spanning three decades. Results: Before 2005, quinolone resistance was limited to low-level nalixidic acid resistance in fewer than 4% of E. coli isolates. In 2005, the proportion of isolates demonstrating low-level quinolone resistance due to elevated efflux increased and high-level quinolone resistance and resistance to the fluoroquinolones appeared. Fluoroquinolone resistance was attributable to single nucleotide polymorphisms in quinolone target genes gyrA and/or parC. By 2009, 35 (34.5%) of isolates were quinolone non-susceptible with nine carrying gyrA and parC SNPs and six bearing identical qnrS1 alleles. The antimalarial chloroquine was heavily used throughout the entire period but E. coli with quinolone-specific resistance mechanisms were only detected in the final half decade, immediately following the introduction of the fluoroquinolone antibacterial ciprofloxacin. Conclusions: Fluoroquinolones, and not chloroquine, appear to be the selective force for fluoroquinolone-resistant fecal E. coli in this setting. Rapid evolution to resistance following fluoroquinolone introduction points the need to implement resistant containment strategies when new antibacterials are introduced into resource-poor settings with high infectious disease burdens

Integrons associated with plasmid replicon types in mother and child pairs isolates.

<p>Integrons associated with plasmid replicon types in mother and child pairs isolates.</p

Frequency of multidrug resistance among faecal <i>Escherichia coli</i> isolates.

<p>Frequency of multidrug resistance among faecal <i>Escherichia coli</i> isolates.</p

Plasmid replicons types detected in strains harboring only one class 1 integron cassette combination and only one replicon marker site.

<p>Plasmid replicons types detected in strains harboring only one class 1 integron cassette combination and only one replicon marker site.</p

Classes 1 and 2 integrons in faecal <i>Escherichia coli</i> strains isolated from mother-child pairs in Nigeria

<div><p>Background</p><p>Antimicrobial resistance among enteric bacteria in Africa is increasingly mediated by integrons on horizontally acquired genetic elements. There have been recent reports of such elements in invasive pathogens across Africa, but very little is known about the faecal reservoir of integron-borne genes.</p><p>Methods and findings</p><p>We screened 1098 faecal <i>Escherichia coli</i> isolates from 134 mother-child pairs for integron cassettes by PCR using primers that anneal to the 5’ and 3’ conserved ends of the cassette regions and for plasmid replicons. Genetic relatedness of isolates was determined by flagellin and multi-locus sequence typing. Integron cassettes were amplified in 410 (37.5%) isolates and were significantly associated with resistance to trimethoprim and multiple resistance. Ten cassette combinations were found in class 1 and two in class 2 integrons. The most common class 1 cassette configurations were single <i>aadA1</i> (23.4%), <i>dfrA7</i> (18.3%) and <i>dfrA5</i> (14.4%). Class 2 cassette configurations were all either <i>dfrA1-satI-aadA1</i> (n = 31, 7.6%) or <i>dfrA1-satI</i> (n = 13, 3.2%). A <i>dfr</i> cassette was detected in 294 (31.1%) of trimethoprim resistant strains and an <i>aadA</i> cassette in 242 (23%) of streptomycin resistant strains. Strains bearing integrons carried a wide range of plasmid replicons of which FIB/Y (n = 169; 41.2%) was the most frequently detected. Nine isolates from five different individuals carried the <i>dfrA17-aadA5</i>-bearing ST69 clonal group A (CGA). The same integron cassette combination was identified from multiple distinct isolates within the same host and between four mother-child pairs.</p><p>Conclusions</p><p>Integrons are important determinants of resistance in faecal <i>E</i>. <i>coli</i>. Plasmids in integron-containing strains may contribute to dispersing resistance genes. There is a need for improved surveillance for resistance and its mechanisms of dissemination and persistence and mobility of resistance genes in the community and clinical settings.</p></div