Multidrug-resistant commensal Escherichia coli in children, Peru and Bolivia

Fermentation broth from fruit and vegetable waste works: Reducing the risk of human bacterial pathogens in soil by inhibiting quorum sensing

Fermentation broth from fruit and vegetable waste (FFVW) has demonstrated remarkable ability as a soil amendment and in reducing antibiotic resistance genes (ARGs) pollution. However, the potential of FFVW to mitigate other microbial contamination such as human bacterial pathogens (HBPs) and virulence factor genes (VFGs), which are closely associated with human health, remains unknown. In this study, metagenomic analysis revealed that FFVW reduced the HBPs with high-risk of ARGs and VFGs including Klebsiella pneumoniae (reduced by 40.4 %), Mycobacterium tuberculosis (reduced by 21.4 %) and Streptococcus pneumoniae (reduced by 38.7 %). Correspondingly, VFG abundance in soil decreased from 3.40 copies/cell to 2.99 copies/cell. Further analysis illustrated that these was mainly attributed to the inhibition of quorum sensing (QS). FFVW reduced the abundance of QS signals, QS synthesis genes such as rpaI and luxS, as well as receptor genes such as rpfC and fusK, resulting in a decreased in risk of ARGs and VFGs. The pure culture experiment revealed that the expression of genes related to QS, VFGs, ARGs and mobile genetic elements (MGEs) were downregulated in Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli and K. pneumoniae treated by FFVW, consistent with the result of metagenomic analysis. This study suggested an environmentally friendly approach for controlling soil VFGs/ARGs-carrying HBPs, which is crucial for both soil and human health under the framework of "One Health".

Multiple resistance factors collectively promote inoculum-dependent dynamic survival during antimicrobial peptide exposure in Enterobacter cloacae

Antimicrobial peptides (AMPs) are a promising tool with which to fight rising antibiotic resistance. However, pathogenic bacteria are equipped with several AMP defense mechanisms, whose contributions to AMP resistance are often poorly defined. Here, we evaluate the genetic determinants of resistance to an insect AMP, cecropin B, in the opportunistic pathogen Enterobacter cloacae. Single-cell analysis of E. cloacae's response to cecropin revealed marked heterogeneity in cell survival, phenotypically reminiscent of heteroresistance (the ability of a subpopulation to grow in the presence of supra-MIC concentration of antimicrobial). The magnitude of this response was highly dependent on initial E. cloacae inoculum. We identified 3 genetic factors which collectively contribute to E. cloacae resistance in response to the AMP cecropin: The PhoPQ-two-component system, OmpT-mediated proteolytic cleavage of cecropin, and Rcs-mediated membrane stress response. Altogether, this evidence suggests that multiple, independent mechanisms contribute to AMP resistance in E. cloacae.

Class 1 and 2 Integrons in Escherichia coli Strains Isolated from Diarrhea and Bacteremia in Children Less Than 2 Years of Age from Peru

Class 1 and Class 2 integrons are mobilizable elements able to carry a variety of antibiotic resistance determinants. In the present study, Class 1 and 2 integrons present in 355 pathogenic Escherichia coli (285 diarrheagenic, of these 129 were enteropathogenic, 90 enteroaggregative, 66 enterotoxigenic, and 70 bacteremic) isolated from healthy and ill children under age 5 from periurban areas of Lima, Peru, were characterized. The presence of integrase 1 and 2 was established by polymerase chain reaction (PCR), and variable regions were grouped by PCR-restriction fragment length polymorphism and subsequent sequencing. Antimicrobial resistance was established by disk diffusion. Ninety-seven isolates (27.3%) presented integrase 1, and 16 (4.5%) presented integrase 2 (P < 0.0001); in addition, seven (2.0%) isolates, six diarrheagenic and one bacteremic, presented both integrase genes. The presence of integrase 1 was more frequent among bacteremic isolates (P = 0.0004). Variable regions were amplified in 76/120 (63.3%) isolates with up to 14 gene arrangements. The most prevalent gene cassettes were those encoding dihydrofolate reductases as well as aminoglycoside modifying enzymes. Of note, Class 1 integrons tended to be associated with the presence of extended-spectrum β-lactamases (ESBLs). A variety of Class 1 and 2 integrons were detected in diarrheagenic and bacteremic E. coli, demonstrating the heterogeneity of variable regions circulating in the area. The association of integrons with ESBLs is worrisome and has an impact on the development of multidrug resistance.

Triterpene and Steroids from Ludwigia abyssinica A. Rich (Onagraceae) Displayed Antimicrobial Activities and Synergistic Effects with Conventional Antibiotics

Difficulties encountered in treating drug-resistant pathogens have created a need for new therapies. Synergistic combinations of antibiotics are considered as ideal strategies in combating clinical and multidrug-resistant (MDR) infections. In this study, the antimicrobial activities of triterpenes and steroids from Ludwigia abyssinica A. Rich (Onagraceae) and their combined effects with antibiotics were assessed. The associations between plant constituents and antibiotics were evaluated by determining their fractional inhibitory concentrations (FICs). Sitost-5-en-3β-ol formiate (1), 5α,6β-dihydroxysitosterol (2), and maslinic acid (3) were isolated from the L. abyssinica ethyl acetate (EtOAc) extract. The EtOAc extract, compounds 1, 2, and 3 (MIC = 16-128 µg/mL) would be the best antibacterial and antifungal agents. The antimicrobial activities of amoxicillin were relatively weak against MDR Escherichia coli and Shigella flexneri and significant against Staphylococcus aureus ATCC 25923. However, when used in association with plant constituents, it displayed an interesting synergistic effect. Among plant components-antibiotic combinations, the EtOAc extract and compound 1 (steroid) showed a synergistic effect with amoxicillin/fluconazole against all the tested microorganisms whereas the association of compound 3 (triterpenoid) and amoxicillin/fluconazole displayed an additive effect against Shigella flexneri and Escherichia coli and a synergistic effect on Staphylococcus aureus, Cryptococcus neoformans, Candida tropicalis, and Candida albicans ATCC 10231. Overall, the results of the present study demonstrated antibacterial and antifungal activities of extracts and compounds isolated from L. abyssinica. The findings of the current study also showed that the potency of antibiotics was improved when screened in combination with L. abyssinica components, supporting the drug combination strategy to combat antimicrobial resistance.

Antibiotic Resistance and Biofilm Development of Escherichia coli on Different Surfaces

The goal of this research is on antibiotic resistance and biofilm formation of Escherichia coli on different surfaces. 37 E.coli isolates were obtained from K.A.P. Viswanatham Government Medical College, Tiruchirappalli, Tamil Nadu, India. Biochemical assays were used to re-confirm all the isolates. Ampicillin, Cefepime, Cefotaxime, Co-trimoxazole, Tetracycline and Levofloxacin showed substantial levels of resistance. Meropenem, Tigecycline, and Colistin showed the least amount of resistance. 75.6% of the E.coli strains were multidrug resistant (MDR). Biofilm formation of E.coli was higher in TSBG than in TSB in all (polystyrene, polypropylene, glass and stainless steel) surfaces. It is evident that the presence of glucose or any sugar substrate promotes biofilm development, resulting in notable antibiotic resistance. This situation is hazardous to human health.

Evidence of Community-Wide Spread of Multi-Drug Resistant Escherichia coli in Young Children in Lusaka and Ndola Districts, Zambia

Increased antimicrobial resistance (AMR) has been reported for pathogenic and commensal Escherichia coli (E. coli), hampering the treatment, and increasing the burden of infectious diarrhoeal diseases in children in developing countries. This study focused on exploring the occurrence, patterns, and possible drivers of AMR E. coli isolated from children under-five years in Zambia. A hospital-based cross-sectional study was conducted in the Lusaka and Ndola districts. Rectal swabs were collected from 565 and 455 diarrhoeic and healthy children, respectively, from which 1020 E. coli were cultured and subjected to antibiotic susceptibility testing. Nearly all E. coli (96.9%) were resistant to at least one antimicrobial agent tested. Further, 700 isolates were Multi-Drug Resistant, 136 were possibly Extensively-Drug Resistant and nine were Pan-Drug-Resistant. Forty percent of the isolates were imipenem-resistant, mostly from healthy children. A questionnaire survey documented a complex pattern of associations between and within the subgroups of the levels of MDR and socio-demographic characteristics, antibiotic stewardship, and guardians’ knowledge of AMR. This study has revealed the severity of AMR in children and the need for a community-specific-risk-based approach to implementing measures to curb the problem.

High Prevalence of blaCTX-M in Fecal Commensal Escherichia coli from Healthy Children

Background

Antibiotic-resistant Escherichia coli can colonize the intestinal tract of healthy children, causing concern when antibiotic resistance is related to the presence of transferable mechanisms, such as extended-spectrum β-lactamases (ESBLs).

Materials and Methods

Fecal samples from 41 healthy children from two villages of rural Peru were cultured on ceftriaxone-disks. ESBL production was confirmed with double disk synergy. In all ESBL-produced isolates, antibiotic susceptibility to 12 antibacterial agents was established by disk diffusion, while clonal relationships were determined by repetitive extragenic palindromic-polymerase chain reaction (REP-PCR). Presence of ST131 was determined using PCR.

Results

Ceftriaxone-resistant microorganisms were recovered from 39 samples belonging to 22 out of 41 children (53.7%). Of these, 80 ceftriaxone-resistant and two ceftriaxone-intermediate E. coli from inside ceftriaxone-halos were confirmed as ESBL-producers. All isolates were multidrug-resistant. In 79/80 (98.8%) ceftriaxone-resistant isolates, the presence of bla_CTX-M was detected alone (58 isolates, or together with other β-lactamase (bla_TEM, 17 isolates; bla_OXA-1-like, 3 isolates; bla_TEM + bla_OXA-1-like, 1 isolate), while in one isolate no such ESBL was identified. The two ceftriaxone-intermediate isolates recovered from the same sample, carried a bla_TEM and bla_SHV respectively. Thirty-four different clones were identified, with 4 clones being recovered from different samples from the same child. Twelve clones were disseminated among different children, including 5 clones disseminated between both villages. Two clones, accounting for 3 isolates and both recovered from the same children, belonged to E. coli ST131.

Conclusion

This study demonstrates high prevalence of ESBL-carriers among healthy children living in a rural area of Peru, stressing the need for continuous surveillance and search for public health control measures.

Prevalence and Molecular Characterization of Fluoroquinolone-Resistant Escherichia coli in Healthy Children

Faecal E. coli can act as reservoirs for resistance genes. Here, we analyzed prevalence of drug resistance in faecal E. coli isolated from healthy children at a single kindergarten in Beijing, China, then used whole genome sequencing to characterize fluoroquinolone-non-susceptible strains. Our results revealed high resistance to ampicillin (54.0%), trimethoprim/sulphurmethoxazole (47.5%) and tetracycline (58.9%) among 576 faecal E. coli isolates, 49.2% of which exhibited multidrug resistance. A total of 113 E. coli isolates were not susceptible to ciprofloxacin, with four sequence types, namely ST1193 (25.7%), ST773 (13.3%), ST648 (8.8%) and ST131 (7.1%) found to be the most prevalent (54.9%). With regards to resistance to quinolones, we detected chromosomal mutations in gyrA, parC, and parE in 111 (98.2%), 105 (92.9%), and 67 (61.1%) isolates, respectively. bla _CTX-M (37.2%) was the major ESBL gene, whereas bla _CTX-M-14 (12.4%) and bla _CTX-M-27 (11.5%) were the most frequent subtypes. A total of 90 (79.6%) ExPEC and 65 (57.5%) UPEC isolates were classified. Overall, these findings revealed clonal spread of certain prevalent STs, namely ST1193, ST773, ST648 and ST131 E. coli isolates in healthy children within a single kindergarten in Beijing, China, affirming the seriousness of the multidrug resistance problem and potential pathogenicity of E. coli isolates in healthy children. Therefore, there is an urgent need for increased surveillance to enhance control of this problem.

Characterization of a Coliphage AS1 isolated from sewage effluent in Pakistan

The emergence of multi-drug resistant (MDR) bacterial strains, which are posing a global health threat has developed the interest of scientists to use bacteriophages instead of conventional antibiotics therapy. In light of an increased interest in the use of phage as a bacterial control agent, the study aimed to isolate and characterize lytic phages from sewage effluent. During the current study, bacteriophage AS1 was isolated from sewage effluent against E.coli S2. The lytic activity of phageAS1 was limited to E.coli S2 strain showing monovalent behavior. The calculated phage titer was 3.5×109 pfu/ml. PhageAS1 was stable at a wide range of pH and temperature. The maximum stability was recorded at 37ºC and pH 7.0, while showing its normal lytic activity at temperature 60ºC and from pH 5.0 to11.0 respectively. At temperature 70ºC, phage activity was somewhat reduced whereas, further increase in temperature and decrease or increase in pH completely inactivated the phage. From the current study, it was concluded that waste water is a best source for finding bacteriophages against multi-drug resistant bacterial strains and can be used as bacterial control agent.

Environmental hotspots for antibiotic resistance genes

Bacterial resistance toward broad-spectrum antibiotics has become a major concern in recent years. The threat posed by the infectious bacteria and the pace with which resistance determinants are transmitted needs to be deciphered. Soil and water contain unique and diverse microbial communities as well as pools of naturally occurring antibiotics resistant genes. Overuse of antibiotics along with poor sanitary practices expose these indigenous microbial communities to antibiotic resistance genes from other bacteria and accelerate the process of acquisition and dissemination. Clinical settings, where most antibiotics are prescribed, are hypothesized to serve as a major hotspot. The predisposition of the surrounding environments to a pool of antibiotic-resistant bacteria facilitates rapid antibiotic resistance among the indigenous microbiota in the soil, water, and clinical environments via horizontal gene transfer. This provides favorable conditions for the development of more multidrug-resistant pathogens. Limitations in detecting gene transfer mechanisms have likely left us underestimating the role played by the surrounding environmental hotspots in the emergence of multidrug-resistant bacteria. This review aims to identify the major drivers responsible for the spread of antibiotic resistance and hotspots responsible for the acquisition of antibiotic resistance genes.

Self-medication Behavior with antibiotics: a national cross-sectional survey in Sri Lanka

BACKGROUND

Antibiotic self-medication is common in low- and middle-income countries. This study aimed to evaluate the Sri Lankan public's knowledge about and attitudes toward antibiotic use and self-medication, and factors associated with self-medication.

METHODS

A national cross-sectional, interviewer-administered, survey of a random household sample (N = 1100) was conducted. Factor analysis of the attitudinal items was conducted to investigate the factors associated with antibiotic self-medication.

RESULTS

A response rate of ninety-one percent (n = 998) responded. Knowledge about antibiotics was poor (mean = 12.5; SD = 3.5; (scale 0-27)). Half had previously used an antibiotic once in the past three months. About 11% (108/998) had self-medicated the last time they took antibiotics; mostly obtained from a pharmacy (82%; 89/108). Three attitudinal factors were obtained, explaining 56.1% of the variance. Respondents were less likely to self-medicate if they did not support ease of access to antibiotics from pharmacies (p< 0.001) and situational use of antibiotics (p= 0.001); supported appropriate use of antibiotics (p= 0.003); and had greater knowledge about prescription requirements for antibiotics (p= 0.004).

CONCLUSION

There is limited knowledge about, and a high rate of self-medication with antibiotics.Factors contributing to self-medication could be addressed with appropriate public education campaigns, and policy changes.

Antimicrobial resistance genes are enriched in aerosols near impacted urban surface waters in La Paz, Bolivia

Antibiotic resistance poses a major global health threat. Understanding emergence and dissemination of antibiotic resistance in environmental media is critical to the design of control strategies. Because antibiotic resistance genes (ARGs) may be aerosolized from contaminated point sources and disseminated more widely in localized environments, we assessed ARGs in aerosols in urban La Paz, Bolivia, where wastewater flows in engineered surface water channels through the densely populated urban core. We quantified key ARGs and a mobile integron (MI) via ddPCR and E. coli spp. as a fecal indicator by culture over two years during both the rainy and dry seasons in sites near wastewater flows. ARG targets represented major antibiotic groups-tetracyclines (tetA), fluoroquinolines (qnrB), and beta-lactams (blaTEM)-and an MI (intI1) represented the potential for mobility of genetic material. Most air samples (82%) had detectable targets above the experimentally determined LOD: most commonly blaTEM and intI1 (68% and 47% respectively) followed by tetA and qnrB (17% and 11% respectively). ARG and MI densities in positive air samples ranged from 1.3 × 101 to 6.6 × 104 gene copies/m3 air. Additionally, we detected culturable E. coli in the air (52% of samples <1 km from impacted surface waters) with an average density of 11 CFU/m3 in positive samples. We observed decreasing density of blaTEM with increasing distance up to 150 m from impacted surface waters. To our knowledge this is the first study conducting absolute quantification and a spatial analysis of ARGs and MIs in ambient urban air of a city with contaminated surface waters. Environments in close proximity to urban wastewater flows in this setting may experience locally elevated concentrations of ARGs, a possible concern for the emergence and dissemination of antimicrobial resistance in cities with poor sanitation.

High prevalence of antibiotic resistance in commensal Escherichia coli from healthy human sources in community settings

Antibiotic resistance is a global health crisis that requires urgent action to stop its spread. To counteract the spread of antibiotic resistance, we must improve our understanding of the origin and spread of resistant bacteria in both community and healthcare settings. Unfortunately, little attention is being given to contain the spread of antibiotic resistance in community settings (i.e., locations outside of a hospital inpatient, acute care setting, or a hospital clinic setting), despite some studies have consistently reported a high prevalence of antibiotic resistance in the community settings. This study aimed to investigate the prevalence of antibiotic resistance in commensal Escherichia coli isolates from healthy humans in community settings in LMICs. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we synthesized studies conducted from 1989 to May 2020. A total of 9363 articles were obtained from the search and prevalence data were extracted from 33 articles and pooled together. This gave a pooled prevalence of antibiotic resistance (top ten antibiotics commonly prescribed in LMICs) in commensal E. coli isolates from human sources in community settings in LMICs of: ampicillin (72% of 13,531 isolates, 95% CI: 65-79), cefotaxime (27% of 6700 isolates, 95% CI: 12-44), chloramphenicol (45% of 7012 isolates, 95% CI: 35-53), ciprofloxacin (17% of 10,618 isolates, 95% CI: 11-25), co-trimoxazole (63% of 10,561 isolates, 95% CI: 52-73), nalidixic acid (30% of 9819 isolates, 95% CI: 21-40), oxytetracycline (78% of 1451 isolates, 95% CI: 65-88), streptomycin (58% of 3831 isolates, 95% CI: 44-72), tetracycline (67% of 11,847 isolates, 95% CI: 59-74), and trimethoprim (67% of 3265 isolates, 95% CI: 59-75). Here, we provided an appraisal of the evidence of the high prevalence of antibiotic resistance by commensal E. coli in community settings in LMICs. Our findings will have important ramifications for public health policy design to contain the spread of antibiotic resistance in community settings. Indeed, commensal E. coli is the main reservoir for spreading antibiotic resistance to other pathogenic enteric bacteria via mobile genetic elements.

Molecular Epidemiology of Enteroaggregative Escherichia coli (EAEC) Isolates of Hospitalized Children from Bolivia Reveal High Heterogeneity and Multidrug-Resistance

Enteroaggregative Escherichia coli (EAEC) is an emerging pathogen frequently associated with acute diarrhea in children and travelers to endemic regions. EAEC was found the most prevalent bacterial diarrheal pathogen from hospitalized Bolivian children less than five years of age with acute diarrhea from 2007 to 2010. Here, we further characterized the epidemiology of EAEC infection, virulence genes, and antimicrobial susceptibility of EAEC isolated from 414 diarrheal and 74 non-diarrheal cases. EAEC isolates were collected and subjected to a PCR-based virulence gene screening of seven virulence genes and a phenotypic resistance test to nine different antimicrobials. Our results showed that atypical EAEC (a-EAEC, AggR-negative) was significantly associated with diarrhea (OR, 1.62, 95% CI, 1.25 to 2.09, p < 0.001) in contrast to typical EAEC (t-EAEC, AggR-positive). EAEC infection was most prevalent among children between 7–12 months of age. The number of cases exhibited a biannual cycle with a major peak during the transition from warm to cold (April–June). Both typical and a-EAEC infections were graded as equally severe; however, t-EAEC harbored more virulence genes. aap, irp2 and pic were the most prevalent genes. Surprisingly, we detected 60% and 52.6% of multidrug resistance (MDR) EAEC among diarrheal and non-diarrheal cases. Resistance to ampicillin, sulfonamides, and tetracyclines was most common, being the corresponding antibiotics, the ones that are frequently used in Bolivia. Our work is the first study that provides comprehensive information on the high heterogenicity of virulence genes in t-EAEC and a- EAEC and the large prevalence of MDR EAEC in Bolivia.

Antimicrobial resistance and metallo-beta-lactamase producing among commensal Escherichia coli isolates from healthy children of Khuzestan and Fars provinces; Iran

Background

The emergence of metallo-β-lactamase (MBL)-producing isolates is alarming since they carry mobile genetic elements with great ability to spread; therefore, early detection of these isolates, particularly their reservoir, is crucial to prevent their inter- and intra-care setting dissemination and establish suitable antimicrobial therapies. The current study was designed to evaluate the frequency of antimicrobial resistance (AMR), MBL producers and identification of MBL resistance genes in Escherichia coli strains isolated from fecal samples of the healthy children under 3 years old. A total of 412 fecal E. coli isolates were collected from October 2017 to December 2018. The study population included healthy infants and children aged < 3 years who did not exhibit symptoms of any diseases, especially gastrointestinal diseases. E. coli isolates were assessed to determine the pattern of AMR. E. coli isolates were assessed to determine the pattern of AMR, the production of extended spectrum β-lactamase (ESBL) and MBL by phenotypic methods. Carbapenem-resistant isolates were investigated for the presence of MBL and carbapenemase genes, plasmid profiling, and the ability of conjugation.

Results

In sum, AMR, multi-drug resistance (MDR) and ESBL production were observed in more than 54.9, 36.2 and 11.7% of commensal E. coli isolates, respectively. Out of six isolates resistant to imipenem and meropenem, four isolates were phenotypically detected as MBL producers. Two and one E. coli strains carried the bla_NDM-1 and bla_VIM-2 genes, respectively and were able to transmit imipenem resistance through conjugation.

Conclusion

Our findings showed that children not exposed to antibiotics can be colonized by E. coli isolates resistant to the commonly used antimicrobial compounds and can be a good indicator for the occurrence and prevalence of AMR in the community. These bacteria can act as a potential reservoir of AMR genes including MBL genes of pathogenic bacteria and lead to the dissemination of resistance mechanisms to other bacteria.

Antimicrobial resistance of Escherichia coli, isolated from children's intestinal microbiota

Recent studies have shown that bacterial resistance existed long before antimicrobials were used in medicine, and not only pathogens are resistant to antibiotics. 511 strains of E. coli isolated from the intestinal microbiota of children aged 1 month to 17 years living in St. Petersburg were studied: the susceptibility to 15 antibiotics was determined by the disk diffusion method, as well as the susceptibility to 6 commercial bacteriophages produced by «Microgen» (Russia). The b-lactamase genes of molecular families TEM, SHV, OXA, and CTX-M were detected by multiplex PCR. 39,3% E. coli isolates were resistant to one or more antimicrobial classes. The proportion of multidrug resistant isolates (resistant to 3 or more classes) was 16,6%. Multidrug resistance to clinically significant antimicrobial classes (extended-spectrum cephalosporins (ESC) + fluoroquinolones + aminoglycosides) was detected in 0,8% isolates. Resistance to aminopenicillins was detected in 29,5%, ESC - 11,2%, fluoroquinolones - 13,3%, tetracycline - 20,0%, chloramphenicol - 9,8%, aminoglycosides - 2,5% isolates. b-lactam resistance was due to the beta-lactamase production: to ampicillin - the molecular family TEM (81,9%), ESC - the CTX-M molecular family (87,7%) CTX-M1 - (66%) and CTX-M9 groups (34%). 43,5% multidrug resistant E. coli isolates were susceptible to at least one of the six commercial bacteriophages produced by «Microgen». The study showed that the intestinal microbiota of children is an important reservoir of E. coli resistant (including multidrug resistance) to various classes of antibiotics, and bacteriophage therapy is an alternative method for eradication of antibiotic-resistant E. coli.

Development of Gentamicin Resistance During Treatment of Escherichia coli Ventilator-Associated Pneumonia in a Neonate

A neonate born at 25 + 1/7 weeks developed ventilator-associated pneumonia at 29 + 3/7 weeks post-menstrual age with Escherichia coli that was originally sensitive to gentamicin. After 3 days of treatment with gentamicin, the minimum inhibitory concentration (MIC) changed from less than 1 mg/L to more than 16 mg/L. It appears that suboptimal gentamicin dosing led to the development of gentamicin resistance. As the patient was not improving clinically, the antibiotics were changed once the gentamicin resistance was identified. To minimize resistance and treatment failure, clinicians should consider the patient-specific pharmacokinetic parameters, achieved peak level, and the amount of time the gentamicin level will remain below the MIC of the organism being treated.

Green synthesis, characterization, antimicrobial and cytotoxic effect of silver nanoparticles using arabinoxylan isolated from Kalmegh

A green synthesis of silver nanoparticles was synthesized by AgNO₃ with arabinoxylan, isolated from green stem of Andrographis paniculata (Kalmegh). The synthesized Ag NPs-arabinoxylan conjugates were characterized by UV-vis spectroscopy, FE-SEM, TEM, XRD, TGA, EDX, and Zeta potential experiments. The Ag NPs formation was established by the surface plasmon resonance band ~410.25 nm. SEM image showed mostly spherical morphology of Ag NPs. The fcc crystalline nature was identified by XRD, SAED and the size were 24.5 and 25 nm from TEM and XRD analysis respectively. The prepared Ag NPs showed dose-dependent antimicrobial activity against Streptococcus pneumonia, Candida albicans and E. coli. The nanoparciles damage 4% hemolysis to human RBCs at 12.5 μg/mL. MTT assay of Ag NPs showed that half of the cell killed at 10 μg/mL and wound healing assay observed effective inhibition cell proliferation.

Prevalence and antimicrobial susceptibility of Salmonella and Shigella species isolated from diarrheic children in Ambo town

BACKGROUND

Diarrhea, particularly of enteric bacterial pathogen, remains a major cause of morbidity and mortality in Ethiopia. Despite the high prevalence of diarrheal disease among under-five children, antibiotic resistance of bacterial pathogens test is not part of routine childcare in the study area. This study aimed to investigate the prevalence and antimicrobial susceptibility status of Salmonella and Shigella species among diarrheic children attending public health institutions in Ambo town, west Showa, Ethiopia.

METHODS

Institutional based, cross-sectional study was carried out from January to July 2014 among 239 diarrheic children below five years of age in Ambo town, Ethiopia. Information about patient demographics, signs, and symptoms was obtained from the parents/guardians of each child using a questionnaire. Stool samples from diarrheic children were collected and processed for isolation of Salmonella and Shigella using conventional microbiology procedures. Suspected Salmonella isolates were confirmed by genus-specific PCR and serotyped using a slide agglutination test. Susceptibility to 10 commonly used antimicrobials was assessed using the Kirby Bauer disc diffusion method.

RESULTS

From the 239 children screened, only nine (3.8%) of them were positive for either Salmonella (n = 3) or Shigella (n = 6) and 19 (7.9%) positive for the intestinal parasite. Three species of Shigella were identified: Shigella flexinari (n = 3), Shigella boydii (n = 2), and Shigella sonnei (n = 1). The three Salmonella isolates were S. chicago, S. caracas, and S. saintpaul. Salmonella and Shigella isolates were resistant to ampicillin (88.9%), followed by tetracycline (66.7%), cotrimoxazole (55.6%), chloramphenicol (44.4%), amoxicillin (33.3%), nalidixic acid (11.1%) and cefotaxime (11.1%). All isolates were sensitive to amikacin, ciprofloxacin, and gentamycin.

CONCLUSION

In this study, either Salmonella or Shigella species were detected only in 3.8% of diarrheic children in Ambo town, suggesting the dominance of other causes of diarrhea in the study area. A further study targeting other causes of diarrhea should be conducted to establish the major causes of childhood diarrhea in the study area.

Antibiotic-Resistant Escherichia coli in Drinking Water Samples from Rural Andean Households in Cajamarca, Peru

Antibiotic resistance in pathogenic bacteria is a serious public health issue. The growing threat is a cause for concern and action to prevent the emergence of new resistant strains and the spread of existing ones to humans via the environment. This study aimed at identifying fecal pathogens in drinking water obtained from rural Andean households from Cajamarca, Peru, and measuring the antibiotic resistance profile of Escherichia coli. The study was embedded within a community-randomized controlled trial among 102 communities in the northern highlands of the Cajamarca region, Peru. Of 314 samples, 55.4% (95% CI [49.7, 61.0], n = 174) were identified as thermotolerant coliforms. Among the samples positive for thermotolerant coliform, E. coli was isolated in 37.3% (n = 117), Klebsiella spp. in 8.0% (n = 25), Enterobacter spp. in 5.1% (n = 16), and Citrobacter spp. in 2.5% (n = 8). Of the 117 E. coli samples, 48.7% (95% CI [39.4, 58.1], n = 57) showed resistance to any antibiotic. The E. coli antibiotic resistance profile showed highest resistance against tetracycline (37.6%), ampicillin (34.2%), sulfamethoxazole-trimethoprim (21.4%), and nalidixic acid (13%). Some 19.7% (95% CI [12.9, 28.0], n = 23) of the E. coli isolates displayed multidrug resistance, defined as resistance to at least three classes of antibiotics. The CTX-M-3 gene, which encodes extended-spectrum resistance to beta-lactamase antibiotics, was found in one isolate. The high prevalence of fecal contamination in drinking water highlights the importance of household water treatment methods. Likewise, the high levels of antibiotic resistance found indicate a need for further research to identify the origins of potential environmental contamination, misuse, or inadequate disposal of antibiotics.

Prevalence of multidrug-, extensive drug-, and pandrug-resistant commensal Escherichia coli isolated from healthy humans in community settings in low- and middle-income countries: a systematic review and meta-analysis

BACKGROUND

The majority of existing studies aimed at investigating the incidence and prevalence of multidrug-resistance by bacteria have been performed in healthcare settings. Relatively few studies have been conducted in community settings, but these have consistently shown a high prevalence of multidrug-resistant bacteria in low- and middle-income countries (LMICs).

OBJECTIVES

To provide an appraisal of the evidence on the high prevalence of multidrug-, extensive drug-, and pandrug-resistance in commensal Escherichia coli isolates from human sources in community settings in LMICs.

METHODS

Using the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines, PubMed, EMBASE, MEDLINE, Web of Science, CINAHL, and Cochrane Library databases were systematically searched with the search string: 'Enterobacteriaceae', OR 'E. coli', OR 'Escherichia coli', AND 'antibiotic resistance', OR 'antimicrobial resistance', OR 'drug-resistance', AND 'prevalence', OR 'incidence', OR 'morbidity', OR 'odds ratio', OR 'risk ratio', OR 'confidence interval', OR 'p-value', OR 'rate'. Data were extracted and proportional meta-analysis was performed using the Freeman-Tukey transformation random effect model.

RESULTS

The prevalence of multidrug-, extensive drug- and pandrug-resistance were extracted from articles that met our inclusion criteria and pooled together after a systematic screening of 9,369 items. The prevalence of multidrug-resistance was 28% of 14,336 total cases of isolates tested, 95% CI: 23-32. Extensive drug-resistance was 24% of 8,686 total cases of isolates tested, 95% CI: 14-36. Lastly, pandrug-resistance was 5% of 5,670 total cases of isolates tested, 95% CI: 3-8.

CONCLUSION

This paper provides an appraisal of the evidence on the high prevalence of multidrug-, extensive drug- and pandrug-resistance by commensal E. coli in community settings in LMICs. Our results call for greater effort to be placed at the community level in the design of new and improved public health policies to counter the global threat of antibiotic-resistant infections and bacteria.

Susceptibility and Multidrug Resistance Patterns of Escherichia coli Isolated from Cloacal Swabs of Live Broiler Chickens in Bangladesh

Antimicrobial resistance is a major health problem, particularly in developing countries like Bangladesh, where there is a paucity of information on resistance patterns and prevalence of antimicrobial determinants. Therefore, the aims of this study were to investigate the prevalence of resistance, including multi-drug resistance (MDR), and the associated genetic determinants in Escherichia coli isolates from cloacal swabs of live broiler chickens in Bangladesh. Altogether, 400 cloacal swabs (200 from Rajshahi and 200 from Dhaka divisions) were randomly collected from individual chickens in 50 broiler farms. E. coli was isolated and identified using conventional bacteriological culture and biochemical methods. The isolates were further confirmed using genus-specific 16S rRNA-targeted polymerase chain reaction (PCR) primers. Antimicrobial susceptibilities and MDR of the isolates against nine different antimicrobial agents (ampicillin, erythromycin, tetracycline, gentamicin, ciprofloxacin, levofloxacin, trimethoprim-sulfamethoxazole, colistin sulphate, and streptomycin) were determined using the Kirby-Bauer disc diffusion method. Resistance determinants of E. coli to ampicillin (bla_TEM), streptomycin (aadA1), erythromycin [ere(A)], trimethoprim (dfrA1), and tetracycline [tet(A), tet(B)] were screened using PCR. Our results showed that all swab samples were positive for E. coli. The isolates were uniformly resistant to ampicillin, tetracycline, streptomycin, ciprofloxacin, erythromycin, and trimethoprim-sulphamethoxazole. The isolates exhibited highest susceptibility to colistin sulphate (73.5%), followed by gentamicin (49%), and levofloxacin (17%). All isolates were resistant to three classes of antibiotics, 204 isolates (51%) were resistant to four classes, and 56 isolates (14%) were resistant to five. The highest prevalence of antimicrobial resistance gene was recorded for tetracycline (tet(A):95.25%; tet(B):95.25%) followed by ampicillin (bla_TEM:91.25%), streptomycin (aadA1:88.25%), erythromycin (ere(A):84.75%), and trimethoprim (dfrA1:65.5%). In conclusion, surveillance for MDR bacteria in poultry is a critical piece of knowledge, which would be useful for optimizing empiric antimicrobial treatments and exploring alternative antimicrobial agents.

Molecular Characterization of Multidrug-Resistant Escherichia coli Isolates in Azerbaijan Hospitals

Aims: The emergence and clonal occurrence of multidrug-resistant (MDR) Escherichia coli isolates are increasing worldwide. In this study, phenotypic and genotypic characteristics of MDR E. coli isolates overexpressing efflux pump were investigated in medical centers of Azerbaijan. Two hundred nineteen consecutive and nonduplicated isolates of E. coli were collected and screened, and confirmed for extended-spectrum β-lactamase, AmpC, and carbapenemase activities and respective genes. MDR isolates were selected and subjected to efflux pump overexpression assay. Cefoxitin-nonsusceptible isolates were subjected to mutational analysis of promoter region of chromosomal ampC gene. MDR isolates with overexpressed efflux were analyzed for acrR and marR mutations and assigned to multilocus sequence typing. Results: Eighty (36.5%) isolates had MDR pattern, among which 16 (20%) isolates were positive for overexpressed efflux. Ninety-eight of 99 suspected isolates were positive for any β-lactamase genes, particularly CTX-M groups 1 and 9. Ten out of 33 cefoxitin-nonsusceptible isolates had mutations in promoter region of chromosomal AmpC gene, including -32T→A (n = 5), -42C→T, and -18G→A (n = 3) and -13TT and GT insertion (n = 2). Detected mutations in efflux regulatory genes include G103S and Y137H (n = 15), K62R (n = 8), S3N (n = 3), and A53E (n = 1) in marR and L109 (n = 2) and L190 (n = 1) frameshift mutations and T12M, T213I, N214T, I113V, and H115Y point mutations (n = 5) in acrR. Conclusions: Overexpressing efflux pump isolates belonging to sequence type (ST)131 and ST73 clones are emerging in Azerbaijan hospitals. Clonal occurrence of MDR E. coli is an alarming situation in Azerbaijan hospitals.

High levels of drug resistance in commensal E. coli in a cohort of children from rural central India

The world is experiencing crisis of antibiotic resistance not only in pathogenic but also in commensal bacteria. We determine the prevalence of antibiotic resistance in commensal Escherichia coli in young children in rural setting of central India and search for its correlations with demographic and behavioral factors. At seven time points during a period of 2 years we collected stool samples from 125 children; aged 1–3 in a rural area of Madhya Pradesh. We isolated six isolates of E. coli per stool sample and subjected them to antibiotic susceptibility testing. We found resistance to ampicillin, quinolones, cephalosporins, sulfamethoxazole, co-trimoxazole, in at least one isolate from 89% to 100% of children. Extended spectrum beta lactamase producing E. coli were identified in all but one child and multidrug resistance was identified in isolates from all children. Female gender (p = 0.04) and higher wealth (p = 0.03) was significantly correlated with less antibiotic resistance. Thus, the high prevalence of antibiotic resistance in commensal E. coli in rural community from India needs urgent measures to control the growing antibiotic resistance crisis.

Impact of triclosan adaptation on membrane properties, efflux and antimicrobial resistance of Escherichia coli clinical isolates

AIM

Analysing the effect of step-wise exposure of Escherichia coli isolates to sublethal concentrations of triclosan (TCS) that is widely used as an antiseptic, preservative and disinfectant.

METHODS AND RESULTS

Changes in the tolerance to the biocide itself and the cross-resistance to clinically important antibiotics were analysed. The involvement of efflux mechanism was studied as well as the possible implication of modifications in cytoplasmic membrane properties including integrity, permeability, potential and depolarization in the resistance mechanisms. Most of E. coli isolates that were adapted to TCS showed increased antimicrobial resistance, lower outer and inner membrane permeability, higher membrane depolarization, more negative membrane potential and enhanced efflux activity using qRT-PCR. Nonsignificant change in membrane integrity was found in the adapted cells.

CONCLUSION

This study suggests that the extensive use of TCS at sublethal concentrations contributed to the emergence of antibiotic resistance in E. coli clinical isolates, by inducing changes in bacterial membrane properties and enhancing the efflux system.

SIGNIFICANCE AND IMPACT OF THE STUDY

The extensive usage of TCS has a deleterious effect on the spread of antibiotic resistance, and more studies are needed to investigate the molecular mechanisms underlying the effects of TCS.

Excess body weight and age associated with the carriage of fluoroquinolone and third-generation cephalosporin resistance genes in commensal Escherichia coli from a cohort of urban Vietnamese children

PURPOSE

Antimicrobial-resistant bacterial infections in low- and middle-income countries (LMICs) are a well-established global health issue. We aimed to assess the prevalence of and epidemiological factors associated with the carriage of ciprofloxacin- and ceftriaxone-resistant Escherichia coli and associated resistance genes in a cohort of 498 healthy children residing in urban Vietnam.

METHODOLOGY

We cultured rectal swabs onto MacConkey agar supplemented with resistant concentrations of ciprofloxacin and ceftriaxone. Additionally, we screened meta-E. coli populations by conventional PCR to detect plasmid-mediated quinolone resistance (PMQR)- and extended-spectrum β-lactamase (ESBL)-encoding genes. We measured the associations between phenotypic/genotypic resistance and demographic characteristics using logistic regression.Results/Key findings. Ciprofloxacin- and ceftriaxone-resistant E. coli were cultured from the faecal samples of 67.7 % (337/498) and 80.3 % (400/498) of children, respectively. The prevalence of any associated resistance marker in the individual samples was 86.7 % (432/498) for PMQR genes and 90.6 % (451/498) for β-lactamase genes. Overweight children were significantly more likely to carry qnr genes than children with lower weight-for-height z-scores [odds ratios (OR): 1.24; 95 % confidence interval (CI): 10.5-1.48 for each unit increase in weight for height; P=0.01]. Additionally, younger children were significantly more likely to carry ESBL CTX-M genes than older children (OR: 0.97, 95 % CI: 0.94-0.99 for each additional year, P=0.01).

CONCLUSION

The carriage of genotypic and phenotypic antimicrobial resistance is highly prevalent among E. coli in healthy children in the community in Vietnam. Future investigations on the carriage of antimicrobial resistant organisms in LMICs should focus on the progression of carriage from birth and structure of the microbiome in obesity.

Prevalence of antibiotic resistance in commensal Escherichia coli among the children in rural hill communities of Northeast India

Commensal bacteria are the representative of the reservoir of antibiotic resistance genes present in a community. The usage of antibiotics along with the demographic factors is generally associated with an increase in antibiotics resistance in pathogens. Northeast (NE) India is untapped with regard to antibiotic resistance prevalence and spread. In the current study, the prevalence of antibiotic-resistant commensal Escherichia coli in pre-school and school-going children (n = 550, 1–14 years old) from the rural areas of the state of Sikkim—an NE Indian state, with respect to associated demographic factors was investigated. A total of 550 fecal E. coli isolates were collected during July 2015 to June 2017. A structured questionnaire was used to collect data to ascertain the potential factors associated with the carriage of antibiotic resistance E. coli among the children. Statistical analysis along with a logistic regression identified potential external factors affecting the observed antibiotic resistance pattern. The data indicated a high prevalence of resistance to common antibiotics like ampicillin (92%), ceftazidime (90%), cefoxitin (88%), streptomycin (40%) and tetracycline (36%), but no resistance to chloramphenicol. The resistance to the combination of penicillin and quinolone group of antibiotics was observed in fifty-two percent of the isolates. A positive correlation between the harboring of antibiotics resistant E. coli with different demographic factors was observed such as, with children living in nuclear family (vs joint family 63.15%, OR 0.18, 95% CI:0.11–0.28, p < 0.01), below higher secondary maternal education (vs college graduates 59.27% OR 0.75, 95% CI:0.55–1.02, p < 0.02). A close association between different demographic factors and the high prevalence of antibiotic-resistant commensal E. coli in the current study suggests a concern over rising misuse of antibiotics that warrants a future threat of emergence of multidrug-resistant pathogen isolates.

Fecal carriage of multidrug-resistant Escherichia coli by community children in southern Taiwan

BACKGROUND

The emergence of multidrug-resistant (MDR) Escherichia coli (E. coli), particularly E. coli sequence type ST131, is becoming a global concern. Commensal bacteria, an important reservoir of antibiotic resistance genes, facilitate the spread of such genes to pathogenic bacterial strains. The objective of the study is to investigate the fecal carriage of MDR E. coli and ST131 E. coli in community children in Southern Taiwan.

METHODS

In this prospective study, stool samples from children aged 0-18 years were obtained within 3 days of hospitalization from October 2013 to September 2014. Children with a history of underlying diseases, antibiotic treatment, or hospitalization in the 3 months before specimen collection were excluded. E. coli colonies were selected and tested for antimicrobial susceptibility, and O25b-ST131, multilocus sequence typing, and blaCTX-M gene groups were detected.

RESULTS

Among 157 E. coli isolates, the rates of nonsusceptibility to ampicillin, amoxycillin + clavulanate, trimethoprim-sulfamethoxazole, and cefazolin were 70, 65.6, 47.1, and 32.5%, respectively. Twenty-nine (18.5%) isolates were nonsusceptible to ciprofloxacin. MDR E. coli accounted for 58 (37%) of all isolates. Thirteen (8.3%) isolates produced extended-spectrum β-lactamase (ESBL). Furthermore, 26 (16.6%) and 13 (8.3%) isolates were O25b and ST131 positive, respectively. Five (38.5%) of the 13 ESBL-producing E. coli belonged to blaCTX-M group 9, among which were CTXM-14 and 4 (80%) were O25b-ST131 positive. Compared with the non-ESBL and ciprofloxacin-susceptible groups, the ESBL and ciprofloxacin-nonsusceptible groups showed significantly higher rates of O25b-ST131 positivity.

CONCLUSIONS

The prevalence of the fecal carriage of nonsusceptible E. coli in children was high; among these E. coli, 37% were MDR, 18.5% were nonsusceptible to ciprofloxacin, and 8.3% produced ESBL. O25b-ST131 was the most common ESBL-producing E. coli clonal group present in the feces of children, and the ESBL and ciprofloxacin-nonsusceptible groups showed significantly higher rates of O25b-ST131 positivity.

Prevalence and correlates of antibiotic sharing in the Philippines: antibiotic misconceptions and community-level access to non-medical sources of antibiotics

OBJECTIVE

To identify sociodemographic, knowledge and attitudinal correlates to antibiotic sharing among a community-based sample of adults (age 18 and older) in a low-income setting of the Philippines and to explore community-level data on informal antibiotic distribution in roadside stands (i.e., sari-sari stands).

METHODS

Participants (n = 307) completed self-administered surveys. Correlates to antibiotic sharing were assessed using logistic regression with Firth's bias-adjusted estimates. Study staff also visited 106 roadside stands and collected data on availability and characteristics of antibiotics in the stands.

RESULTS

78% had shared antibiotics in their lifetime, most often with family members. In multivariable analysis, agreement with the belief that it is safe to prematurely stop an antibiotic course (OR: 2.8, CI: 1.3-5.8) and concerns about antibiotic side effects (OR: 2.1, CI: 1.1-4.4) were significantly associated with increased odds of reported antibiotic sharing. Antibiotic sharing was not associated with sociodemographic characteristics or antibiotic knowledge. Antibiotics were widely available in 60% of sampled sari-sari stands, in which 59% of antibiotics were missing expiration dates. Amoxicillin and cephalexin were the most commonly available antibiotics for sale at the stands (60% and 21%, respectively).

CONCLUSIONS

Antibiotic sharing was common and was associated with misconceptions about proper antibiotic use. Antibiotics were widely available in sari-sari stands, and usually without expiration information. This study suggests that multipronged and locally tailored approaches to curbing informal antibiotic access are needed in the Philippines and similar Southeast-Asian countries.

Faecal carriage of antibiotic resistant Escherichia coli in asymptomatic children and associations with primary care antibiotic prescribing: a systematic review and meta-analysis

Background

The faecal reservoir provides optimal conditions for the transmission of resistance genes within and between bacterial species. As key transmitters of infection within communities, children are likely important contributors to endemic community resistance. We sought to determine the prevalence of antibiotic-resistant faecal Escherichia coli from asymptomatic children aged between 0 and 17 years worldwide, and investigate the impact of routinely prescribed primary care antibiotics to that resistance.

Methods

A systematic search of Medline, Embase, Cochrane and Web of Knowledge databases from 1940 to 2015. Pooled resistance prevalence for common primary care antibiotics, stratified by study country OECD status. Random-effects meta-analysis to explore the association between antibiotic exposure and resistance.

Results

Thirty-four studies were included. In OECD countries, the pooled resistance prevalence to tetracycline was 37.7 % (95 % CI: 25.9–49.7 %); ampicillin 37.6 % (24.9–54.3 %); and trimethoprim 28.6 % (2.2–71.0 %). Resistance in non-OECD countries was uniformly higher: tetracycline 80.0 % (59.7–95.3 %); ampicillin 67.2 % (45.8–84.9 %); and trimethoprim 81.3 % (40.4–100 %). We found evidence of an association between primary care prescribed antibiotics and resistance lasting for up to 3 months post-prescribing (pooled OR: 1.65, 1.36–2.0).

Conclusions

Resistance to many primary care prescribed antibiotics is common among faecal E. coli carried by asymptomatic children, with higher resistance rates in non-OECD countries. Despite tetracycline being contra-indicated in children, tetracycline resistance rates were high suggesting children could be important recipients and transmitters of resistant bacteria, or that use of other antibiotics is leading to tetracycline resistance via inter-bacteria resistance transmission.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-1697-6) contains supplementary material, which is available to authorized users.

Use of Shotgun Metagenome Sequencing To Detect Fecal Colonization with Multidrug-Resistant Bacteria in Children

Prevention of multidrug-resistant (MDR) bacterial infections relies on accurate detection of these organisms. We investigated shotgun metagenome sequencing for the detection of methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), and MDR Enterobacteriaceae Fecal metagenomes were analyzed from high-risk inpatients and compared to those of low-risk outpatients and controls with minimal risk for a MDR bacterial infection. Principal-component analysis clustered patient samples into distinct cohorts, confirming that the microbiome composition was significantly different between cohorts (P = 0.006). Microbial diversity and relative anaerobe abundance were preserved in outpatients compared to those in controls. Relative anaerobe abundance was significantly reduced in inpatients compared to that in outpatients (P = 0.006). Although the potential for MDR bacteria was increased in inpatients and outpatients compared to that in controls (P < 0.001), there was no difference between inpatients and outpatients. However, 9 (53%) inpatients had colonization with a MDR bacterium that was not identified by culture. Unlike culture, shotgun sequencing quantitatively characterizes the burdens of multiple MDR bacteria relative to all of the microbiota within the intestinal community. We propose consideration of key microbiome features, such as diversity and relative anaerobe abundance, in addition to the detection of MDR bacteria by shotgun metagenome sequencing as a novel method that might better identify patients who are at increased risk of a MDR infection.

Antimicrobial susceptibility profiles of Escherichia coli and Klebsiella pneumoniae isolated from outpatients in urban and rural districts of Uganda

Background

Antimicrobial resistance is a global public health concern contributing to increased morbidity and mortality particularly in low-income countries. Studies on commensal bacteria are important as they reflect the state of antimicrobial susceptibility patterns in populations. However, susceptibility data on potentially pathogenic commensal bacteria from individuals in communities are still limited. The aim of this cross-sectional study was to determine the susceptibility profiles of Escherichia coli and Klebsiella species isolated from clients attending outpatient clinics in Kampala (urban district) and two rural districts of Uganda, Kayunga and Mpigi. Factors associated with such carriage are also reported.

Results

A total of 1448 participants were recruited into the study with 985 yielding organisms of interest from stool or urine samples (one per client). Most growth occurred from stool samples (636/985, 87 %), of which 620/636 (97 %) grew E. coli while 16 (3 %) were Klebsiella pneumoniae. Growth from urine was 349/985 (35 %) of which 310/349 (89 %) were E. coli while 39 (11 %) K. pneumoniae. High rates of antimicrobial resistance were detected among E. coli and Klebsiella isolates combined: sulphamethoxazole/trimethoprim 70 %, amoxicillin/clavulanate 36 %, chloramphenicol 20 %, ciprofloxacin 11 %, gentamicin 11 %, nitrofurantoin 4 %, ceftriaxone 3 %, piperacillin/tazobactam 27 %, cefoxitin 22 %, and cefepime 15 %. Multidrug resistance was noted in 33 % of the isolates. None of the isolates were resistant to imipenem. Overall, isolates from Kampala were more resistant to antimicrobials. Across the three districts combined, isolates producing beta-lactamase enzymes extended spectrum β-lactamase-(ESBL) and AmpC comprised 5.3 and 13.2 %, respectively. Further, medical procedures involving inoculation were independent risk factors [aOR 50.76 (1.80, 1432.90)] while residing in a rural district and use of sulphamethoxazole/trimethoprim 3 months prior to visiting the outpatient clinics were protective against carriage of multidrug resistant isolates. Furthermore, use of gentamicin was protective against AmpC producing isolates while clients attending HIV/AIDs clinics were less likely to carry such isolates. No factor was independently associated with carriage of ESBL-producing isolates.

Conclusion

Antimicrobial resistance is prevalent among E. coli and K.pneumoniae carried in the gut of clients attending outpatient clinics in Kampala and two rural districts in Uganda. This could complicate treatment options for community-acquired infections caused by the Enterobacteriaceae.

Electronic supplementary material

The online version of this article (doi:10.1186/s13104-016-2049-8) contains supplementary material, which is available to authorized users.

Engineered gold nanoparticles for photothermal cancer therapy and bacteria killing

Gold nanoparticle mediated photothermal therapy in future medicine.

Antimicrobial susceptibility and emerging resistance determinants (blaCTX-M, rmtB, fosA3) in clinical isolates from urinary tract infections in the Bolivian Chaco

BACKGROUND

Bolivia is among the lowest-resourced South American countries, with very few data available on antibiotic resistance in bacterial pathogens. The phenotypic and molecular characterization of bacterial isolates responsible for urinary tract infections (UTIs) in the Bolivian Chaco are reported here.

METHODS

All clinical isolates from UTIs collected in the Hospital Basico Villa Montes between June 2010 and January 2014 were analyzed (N=213). Characterization included susceptibility testing, extended-spectrum beta-lactamase (ESBL) detection, identification of relevant resistance determinants (e.g., CTX-M-type ESBLs, 16S rRNA methyltransferases, glutathione S-transferases), and genotyping of CTX-M producers.

RESULTS

Very high resistance rates were observed. Overall, the lowest susceptibility was observed for trimethoprim-sulphamethoxazole, tetracycline, nalidixic acid, amoxicillin-clavulanic acid, ciprofloxacin, and gentamicin. Of E. coli and K. pneumoniae, 11.6% were ESBL producers. Resistance to nitrofurantoin, amikacin, and fosfomycin remained low, and susceptibility to carbapenems was fully preserved. CTX-M-15 was the dominant CTX-M variant. Four E. coli ST131 (two being H30-Rx) were identified. Of note, isolates harbouring rmtB and fosA3 were detected.

CONCLUSIONS

Bolivia is not an exception to the very high resistance burden affecting many South American countries. Optimization of alternative approaches to monitor local antibiotic resistance trends in resource-limited settings is strongly encouraged to support the implementation of effective empiric treatment guidelines.

Occurrence of SHV, TEM and CTX-M β-Lactamase Genes Among Enteropathogenic Escherichia coli Strains Isolated From Children With Diarrhea

Background:

Antibiotic resistance is widespread among diarrheagenic Escherichia coli in developing countries, where the overuse of antibiotics is common. Information regarding β-lactamases, especially Extended-Spectrum β-Lactamases (ESBLs) in diarrheagenic pathogens should be considered in clinical management when an optimal treatment is needed.

Objectives:

The main objective of this study was to investigate the prevalence of bla_CTX-M, bla_SHV and bla_TEM β-lactamase genes among enteropathogenic E. coli (EPEC) isolates in Tehran, Iran.

Materials and Methods:

Stool specimens were collected from children with diarrhea during a 17-month period from 2011 to 2013. Routine biochemical tests were performed for identification of E. coli isolates. The isolates were further examined by PCR for the presence of eae, stx1, stx2 and bfp genes. EPEC isolates have been screened for different β-lactamase genes. Genotyping EPEC isolates harboring bla_CTX-M15 gene was performed through Multi-Locus VNTR Analysis (MLVA).

Results:

Of 42 EPEC, eight isolates carried the bla_CTX-M1. None of the isolates carried bla_CTX-M2 and bla_CTX-M9. The bla_CTX-M15 variant was identified in all of bla_CTX-M1-positive isolates. Furthermore, bla_SHV and bla_TEM genes were detected in 40.5% (n = 17) and 19% (n = 8) of all EPEC isolates, respectively. No significant association was observed between the existence of bfp gene and presence of those β-lactamase genes (P > 0.05). MLVA analysis revealed high genetic diversity among bla_CTX-M15-positive isolates.

Conclusions:

Our study emphasized the increasing role of ESBL genes, especially bla_CTX-M15 in EPEC isolates.

Antibiotic use and emerging resistance: how can resource-limited countries turn the tide?

Antibiotic resistance is a global crisis driven by appropriate and inappropriate antibiotic use to treat human illness and promote animal growth. The antimicrobial resistance epidemic continues to spread due to the triple threat of unfettered access, minimal product regulation and oversight of antibiotic prescription, and lack of clinical diagnostic tools to support antibiotic de-escalation in low-resource settings. In high-resource settings, evidence-based strategies have improved the appropriateness of antibiotic use, limiting the spread of drug-resistant organisms and reducing hospital-associated infections, strategies which may also be effective to stop the spread of resistance in resource-poor countries. Current research and surveillance efforts on antimicrobial resistance and hospital-associated infections in low-resource settings are extremely limited and largely focused on intensive care units. Many challenges exist to improving antibiotic use and infection control in resource-limited settings, and turning the tide requires intensifying research and surveillance, antimicrobial stewardship, and developing new bedside diagnostic tools for bacterial infections and antimicrobial susceptibility.

Comparison of phenotypic characteristics and antimicrobial resistance patterns of clinical Escherichia coli collected from two unrelated geographical areas

Background:

Antimicrobial resistance among pathogenic Escherichia coli is an increasing problem especially in developing countries.

Aims:

To compare between resistance patterns of E. coli collected from two unrelated geographical areas.

Methods:

A descriptive comparative study was conducted between May 2010 and August 2011. E. coli (n= 402) collected from hospitals in Khartoum state, Sudan and in Aseer region, Saudi Arabia were studied. Identification and antimicrobial susceptibility testing of isolates were performed following standard methods. Multi-drug resistance (MDR) was defined as non-susceptibility to ≥ three antimicrobials.

Results:

Of the 402 E. coli isolates studied, MDR patterns were significantly higher among isolates from Sudan than Saudi Arabia [92.2% (214/232) vs. 70.6% (120/170)] (p = 0.000). The resistance rates of E. coli isolates were recorded as follows (Sudan and Saudi Arabia): High to moderate resistance to amoxicillin (97.7% and 94.2%), trimethoprim-sulfamethoxazole (88.3% and 82.5%), tetracycline (77.1% and 74.2%), amoxicillin- clavulanic acid (51.4% and 70%), ceftriaxone (64% and 52.4%) and ciprofloxacin (58.4% and 40%). Low resistance was to ceftazidime (35% and 20%), gentamicin (35% and 17.5%) and nitrofurantoin (22.4% and 11.7%). Resistance to amikacin was uncommon (1.9% and 5%). Significant differences (p < 0.05) in resistance rates of isolates between both countries in term to patient’s gender and age. The most frequent MDR phenotypes among isolates were to 7(15.9%) in Khartoum state and to 3(20.8%) in Aseer region.

Conclusions:

Variation and emerging of antimicrobial resistance among pathogenic E. coli isolates was observed in both regions. Continuous monitoring of resistance profiles, locally and international surveillance programs are required.

Associations between host characteristics and antimicrobial resistance ofSalmonellaTyphimurium

A collection ofSalmonellaTyphimurium isolates obtained from sporadic salmonellosis cases in humans from Lower Saxony, Germany between June 2008 and May 2010 was used to perform an exploratory risk-factor analysis on antimicrobial resistance (AMR) using comprehensive host information on sociodemographic attributes, medical history, food habits and animal contact. Multivariate resistance profiles of minimum inhibitory concentrations for 13 antimicrobial agents were analysed using a non-parametric approach with multifactorial models adjusted for phage types. Statistically significant associations were observed for consumption of antimicrobial agents, region type and three factors on egg-purchasing behaviour, indicating that besides antimicrobial use the proximity to other community members, health consciousness and other lifestyle-related attributes may play a role in the dissemination of resistances. Furthermore, a statistically significant increase in AMR from the first study year to the second year was observed.

Pediatric fecal microbiota harbor diverse and novel antibiotic resistance genes

Emerging antibiotic resistance threatens human health. Gut microbes are an epidemiologically important reservoir of resistance genes (resistome), yet prior studies indicate that the true diversity of gut-associated resistomes has been underestimated. To deeply characterize the pediatric gut-associated resistome, we created metagenomic recombinant libraries in an Escherichia coli host using fecal DNA from 22 healthy infants and children (most without recent antibiotic exposure), and performed functional selections for resistance to 18 antibiotics from eight drug classes. Resistance-conferring DNA fragments were sequenced (Illumina HiSeq 2000), and reads assembled and annotated with the PARFuMS computational pipeline. Resistance to 14 of the 18 antibiotics was found in stools of infants and children. Recovered genes included chloramphenicol acetyltransferases, drug-resistant dihydrofolate reductases, rRNA methyltransferases, transcriptional regulators, multidrug efflux pumps, and every major class of beta-lactamase, aminoglycoside-modifying enzyme, and tetracycline resistance protein. Many resistance-conferring sequences were mobilizable; some had low identity to any known organism, emphasizing cryptic organisms as potentially important resistance reservoirs. We functionally confirmed three novel resistance genes, including a 16S rRNA methylase conferring aminoglycoside resistance, and two tetracycline-resistance proteins nearly identical to a bifidobacterial MFS transporter (B. longum s. longum JDM301). We provide the first report to our knowledge of resistance to folate-synthesis inhibitors conferred by a predicted Nudix hydrolase (part of the folate synthesis pathway). This functional metagenomic survey of gut-associated resistomes, the largest of its kind to date, demonstrates that fecal resistomes of healthy children are far more diverse than previously suspected, that clinically relevant resistance genes are present even without recent selective antibiotic pressure in the human host, and that cryptic gut microbes are an important resistance reservoir. The observed transferability of gut-associated resistance genes to a gram-negative (E. coli) host also suggests that the potential for gut-associated resistomes to threaten human health by mediating antibiotic resistance in pathogens warrants further investigation.

Antibiotic resistance among Escherichia coli isolates from stool samples of children aged 3 to 14 years from Ujjain, India

Background

Antibiotic resistance is a major global public health concern, particularly in settings where few treatment options are available. Limited research has been done on antibiotic resistance in Escherichia coli of Indian children at community level. Therefore we studied antibiotic resistance patterns in E. coli isolates from stool samples of children aged 3-14 years from Ujjain, Central India, to investigate associations of resistance with demographic variables.

Methods

Children, 3-14 years of age, were included from 30 randomly selected villages of Palwa demographic surveillance site, Ujjain, India. Parents were interviewed using a questionnaire, and stool samples were collected from participating children. E. coli were isolated from stool samples (n = 529), and susceptibility testing to 18 different antibiotics was done using standard methods.

Results

The proportions of isolates resistant to various antibiotics were, nalidixic acid, (45%), tetracycline (37%), ampicillin (37%), sulfamethoxazole/trimethoprim (29%) and amoxicillin/clavulanic acid (29%). No isolates were resistant to imipenem. Overall, 72% of isolates were resistant to at least one antibiotic and 33% were multi-drug resistant. High rates of cross-resistance were seen for 15 (83%) of the antibiotics studied. E. coli isolates from children with literate mothers were more resistant to penicillins and fluoroquinolones. ESBL-producers comprised 9% of the isolates.

Conclusion

Antibiotic resistance and cross-resistance were common in E. coli from stools of children. Resistance rates were associated with maternal literacy.

A one-year prospective study on the antibiotic resistance of E. coli strains isolated in urinary specimens of children hospitalized at the University Pediatric Medical Center in Novi Sad, Serbia

PURPOSE

Urinary tract infections (UTIs), the most common serious bacterial infections in children, are frequently caused by Escherichia coli. The purpose of this study was to investigate E. coli resistance/multidrug resistance to antibiotics most frequently used for UTIs.

METHODS

Children 0-18 years of age, hospitalized at the University Pediatric Hospital in Novi Sad, Serbia, were included in a 1-year observational prospective study. The microbiological analysis was performed using the standard Kirby-Bauer disk diffusion method. The results were analyzed using WHONET 5.4 software.

RESULTS

E. coli was isolated from 61.7 % of positive urine specimens. In general, higher average E. coli antibiotic resistance was found in infants and toddlers compared to children and adolescents (33.4 vs. 25.0 %) (p < 0.0001). Furthermore, it was observed that the average resistance to all the tested antibiotics was higher in boys than in girls (37.0 vs. 25.1 %) (p < 0.0001). E. coli was highly susceptible to piperacillin/tazobactam (>93.1 %), amikacin (86.3 %), quinolones (>75.0 %), and penems (>96.6 %). The prevalence of multiresistant E. coli strains was significantly higher in infants and toddlers (72.3 vs. 36.8 %) (p < 0.0001).

CONCLUSIONS

E. coli, a common cause of UTIs in children admitted to pediatric hospitals, is highly resistant/multidrug-resistant to commonly used antibiotics. Higher average resistance is found in infants and toddlers than in children and adolescents, as well as in boys compared to girls. These findings are important for the regional empiric therapy of UTIs and call for actions to decrease E. coli antibiotic resistance.

Factors affecting caregivers' use of antibiotics available without a prescription in Peru

OBJECTIVE

To determine factors that affect caregivers' decisions about antibiotic use in children in settings where antibiotics are available without prescription.

METHODS

In a house-to-house survey, 1200 caregivers in 3 periurban districts of Lima, Peru, were asked about antibiotic use in young children.

RESULTS

In this sample, 87.2% of children aged <5 years had received an antibiotic drug in their lives; 70.3% had received antibiotics before 1 year of age, and 98.8% of those had been prescribed by a physician. Given hypothetical cases of common cold and nondysenteric diarrhea, caregivers would seek medical advice in 76.4% and 87.1%, respectively, and 84.6% of caregivers said they respected medical decisions even if an antibiotic was not prescribed. Caregivers with high school-level education accepted 80% more medical decisions of not using an antibiotic and used fewer pharmacist-recommended antibiotics. For each additional year of life, the risk of self-medicated antibiotic use and the use of pharmacist-recommended antibiotics increased in 30%. (OR: 1.3, 95% CI: 1.1-1.4, P = .001 and OR: 1.3, 95% CI: 1.2-1.5, P < .001, respectively). Caregivers respected a medical decision of not prescribing an antibiotic 5 times more when physicians had explained the reason for their advice (OR: 5.0, 95% CI: 3.2-7.8, P < .001).

CONCLUSIONS

Prescribed antibiotic use in these young children is common. Even if they are available without prescription, caregivers usually comply with medical advice and follow physicians' recommendations when antibiotics are not prescribed. Improving physician prescribing habits could reduce irrational antibiotic use, decreasing future caregiver-driven misuse.