High frequency of antimicrobial resistance in human fecal flora

Abstract

The frequency of resistance to seven different antimicrobial agents was examined in the aerobic gramnegative gut flora of over 600 individuals from hospitals, from laboratories where antibiotics were used, and from urban and rural communities. In a majority (62.5%) of fecal samples from people without a recent history of taking antibiotics, 10% or more of the total organisms were resistant to at least one of the antibiotics. In about 40% of the samples, resistance to more than one drug was present at this level. More than one-third of the samples contained resistant organisms comprising 50% or more of the total flora examined. Organisms with coresistance to multiple drugs were found frequently. Individuals taking antibiotics produced more samples with a higher proportion (>50%) of resistant bacteria, and these samples also had a significantly greater number of different resistance determinants. This extensive study revealed a high prevalence of resistant bacteria in the gut flora of ambulatory and hospitalized individuals whether or not they were taking antibiotics.There is worldwide concern about the appearance of antibiotic resistance in common pathogens of hospital-and community-acquired infections (4,9,20). While selective pressure caused by antibiotic usage has been linked to these findings (20), there have been little data on the natural frequency of antibiotic resistance genes in the nornial nonpathogenic flora of ambulating and hospitalized individuals. Such resistant bacteria would represent a constant pool of resistance genes potentially transferable, directly or indirectly, to human pathogens. We analyzed fecal specimens from humans in the greater Boston, Mass., area for both the presence and frequency of naturally occurring aerobic gramnegative bacteria with resistance to one or more of seven different antimicrobial agents. We found that resistance was common in the gut flora and the resistant strains constituted a major fraction of the total flora in more than one-third of the samples.

The prevalence of antimicrobial resistance in human faecal flora in South Africa

“…However, this contrasts with other findings: examination of child day-care centres (DCC) [17] revealed substantially higher levels of trimethoprimresistant faecal flora (30%) amongst the children attending the centre than is prevalent in the general population (6%). Similarly, ampicillin-resistant faecal flora was reported as 70% in this particular population which again is substantially higher than corresponding levels identified in the healthy community (34 9 %) [9]. In the current study, approximately half the urban infants attended a child-minder in SOWETO, the equivalent of a child day-care centre, and yet the levels of resistance observed in this particular group are not noticeably higher than any other sub-group.…”

“…In contrast, the incidence of such resistance amongst the normal non-pathogenic 222 P. M. A. SHANAHAN AND OTHERS flora such as Escherichia coli of healthy individuals, in the absence of concurrent or recent antibiotic consumption, has been less extensively recorded [8][9][10][11]. The carriage of resistance determinants in these organisms may complicate treatment as the potential exists firstly, for their transfer to any invading pathogens and secondly, the resistant bacteria may cause an endogenous infection [12].…”

“…Candidates were excluded from the study if they had received any medical treatment in the 3 weeks prior to sampling. This time period allowed any changes in faecal flora, resulting from antimicrobial usage, to be reversed [9,18]. A completed questionnaire accompanied each specimen; it supplied information regarding the donor's age, sex, address, medical history and data on social conditions.…”

Country-specific antibiotic use practices impact the human gut resistome

“…A linkage of fecal carriage of resistant bacteria to human antibiotic consumption has been demonstrated (Levy et al 1988;Barbosa and Levy 2000), and previous comparative studies have also revealed higher human antibiotic consumption in southern Europe than in Denmark (Fig. 2D, top and bottom left; Goossens et al 2005;Borg 2012), as well as higher proportions of resistant bacteria isolated from food-producing animals ( Table S1), and for which the time since introduction and animal usage approval information was available.…”

Características microbiológicas do suco de laranja in natura

“…Alguns autores associam o consumo de alimentos vegetais como fontes de bactérias resistentes a antimicrobianos, principalmente da família Enterobacteriaceae, encontradas em amostras fecais de humanos saudáveis, mesmo na ausência de seleção por uso de terapia antimicrobiana [7,12].…”