'Filth flies' feed and develop in excrement and decaying matter and can transmit enteric pathogens to humans and animals, leading to colonization and infection. Considering these characteristics, 'filth flies' are potential vectors for the spread of antimicrobial resistance (AMR). This review defines the role of flies in the spread of AMR and identifies knowledge gaps. The literature search (original articles, reviews indexed for PubMed) was restricted to the English language. References of identified studies were screened for additional sources. 'Filth flies' are colonized with antimicrobial-resistant bacteria of clinical relevance. This includes extended spectrum beta-lactamase-, carbapenemase-producing and colistin-resistant (mcr-1 positive) bacteria. Resistant bacteria in flies often share the same genotypes with bacteria from humans and animals when their habitat overlap. The risk of transmission is most likely highest for enteric bacteria as they are shed in high concentration in excrements and are easily picked up by flies. 'Filth flies' can 'bio-enhance' the transmission of AMR as bacteria multiply in the digestive tract, mouthparts and regurgitation spots. To better understand the medical importance of AMR in flies, quantitative risk assessment models should be refined and fed with additional data (e.g. vectorial capacity, colonization dose). This requires targeted ecological, epidemiological and in vivo experimental studies.

Extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) are sporadically reported from infections in sub-Saharan Africa. Travellers returning from the tropics have a high risk of ESBL-E colonization, which suggests a high prevalence of ESBL-E in Africa. Our objective was to assess the burden of rectal ESBL-E colonization and associated risk factors in Gabon, Central Africa We performed a cross-sectional study on 200 hospitalized children in Gabon, Central Africa, on rectal ESBL-E colonization and applied a standardized questionnaire to assess risk factors. The antimicrobial resistance and the type of β-lactamase (SHV, TEM and CTX-M) were analysed for each isolate. Isolates associated with nosocomial spread were further genotyped. The overall colonization rate of ESBL-E was 45% (n = 90) and increased from 33.6% (n = 37) at admission to 94.1% (n = 16) during hospitalization. Risk factors for ESBL-E carriage were age <5 years, hospitalization for ≥5 days and a hospital stay during the past year. All isolates were susceptible to meropenem, but non-susceptible to ciprofloxacin in 52.8% (n = 57). CTX-M-15 was the predominant β-lactamase. Genotyping revealed a polyclonal structure of nosocomial isolates. ESBL colonization in hospitalized children in Gabon is high. The risk of nosocomial transmission of ESBL-E is a challenge in rural Africa and underlines the need for sentinel surveillance in the absence of a broad decentralized microbiology laboratory.

Background: Physicians depend on reliable information on the local epidemiology of infection and antibiotic resistance rates to guide empiric treatment in critically ill patients. As these data are scarce for Central Africa, we performed a retrospective analysis of microbiological findings from a secondary care hospital in Gabon. Methods: Microbiological reports from 2009 to 2012 were used to assess the non-susceptibility rates of the three most common isolates from six major types of infections (bloodstream, ear-eye-nose-throat, surgical site, skin and soft tissue, urinary tract and wound infection). Results: A high diversity of pathogens was found, but Staphylococcus aureus was predominant in the majority of infections. Overall, the three most prevalent pathogens in children were S. aureus (33.7%), Streptococcus pyogenes (8.1%) and Escherichia coli (4.5%) and in adults S. aureus (23.5%), E. coli (15.1%) and Klebsiella pneumoniae (7.4%). In total, 5.8% (n = 19) of all S. aureus isolates were methicillin resistant. The proportion of extended-spectrum beta-lactamase (ESBL) producing Enterobacteriaceae was 15.4% (n = 78), 49.4% of all K. pneumoniae were ESBL-producer (n = 42). Conclusion: The high diversity of potential pathogens and high resistance rates in Gram-negative bacteria challenge a rational empiric use of antibiotics. Countrywide continuous sentinel surveillance is therefore urgently needed.