Drug resistance in Indian isolates of enteropathogenic <Emphasis Type="Italic">Escherichia coli</Emphasis>

Five different strains of enteropathogenic Escherichia coli (EPEC) and one non-pathogenic strain of E. coli were studied for the determination of resistance to various antibiotics by disc inhibition test. Our results demonstrated multiple drug resistance among the selected E. coli isolates with all of them including the non-pathogenic control strain showing high resistance towards ampicillin. Our results from conjugation test clearly showed the presence of most of the antibiotic markers on the transferred plasmids. Simultaneously, the plasmid profile of conjugants also indicated the presence of more than one plasmid along with the expected megaplasmid of ~90 Kb present in them. Thus our results amply demonstrate that these drug markers are associated with these mobile plasmids.     

Bloodstream Infection among Adults in Phnom Penh,Cambodia: Key Pathogens and Resistance Patterns

Background

Bloodstream infections (BSI) cause important morbidity and mortality worldwide. In Cambodia, no surveillance data on BSI are available so far.

Methods

From all adults presenting with SIRS at Sihanouk Hospital Centre of HOPE (July 2007–December 2010), 20 ml blood was cultured. Isolates were identified using standard microbiological techniques; antibiotic susceptibilities were assessed using disk diffusion and MicroScan®, with additional E-test, D-test and double disk test where applicable, according to CLSI guidelines.

Results

A total of 5714 samples from 4833 adult patients yielded 501 clinically significant organisms (8.8%) of which 445 available for further analysis. The patients’ median age was 45 years (range 15–99 y), 52.7% were women. HIV-infection and diabetes were present in 15.6% and 8.8% of patients respectively. The overall mortality was 22.5%. Key pathogens included Escherichia coli (n = 132; 29.7%), Salmonella spp. (n = 64; 14.4%), Burkholderia pseudomallei (n = 56; 12.6%) and Staphylococcus aureus (n = 53; 11.9%). Methicillin resistance was seen in 10/46 (21.7%) S. aureus; 4 of them were co-resistant to erythromycin, clindamycin, moxifloxacin and sulphamethoxazole-trimethoprim (SMX-TMP). We noted combined resistance to amoxicillin, SMX-TMP and ciprofloxacin in 81 E. coli isolates (62.3%); 62 isolates (47.7%) were confirmed as producers of extended spectrum beta-lactamase. Salmonella isolates displayed high rates of multidrug resistance (71.2%) with high rates of decreased ciprofloxacin susceptibility (90.0%) in Salmonella Typhi while carbapenem resistance was observed in 5.0% of 20 Acinetobacter sp. isolates.

Conclusions

BSI in Cambodian adults is mainly caused by difficult-to-treat pathogens. These data urge for microbiological capacity building, nationwide surveillance and solid interventions to contain antibiotic resistance.     

Concordance of antibiotic resistance and ERIC-PCR DNA fingerprint pattern in <Emphasis Type="Italic">Escherichia coli</Emphasis> isolated from farmer and broiler in the same farm

The study was conducted to quantify the concordance of antibiotic resistance and ERIC-PCR DNA fingerprint pattern in Escherichia coli (E. coli) isolated from farmers and their broilers of 95 broiler farms in Songkhla province, Thailand. Four hundred and fifty-seven and 460 E. coli isolates from both groups produced 35 patterns of antibiotics resistance. Mono-resistance to doxycycline (23.2%) in isolates from farmers and multiple resistance to doxycycline, nalidixic acid, norfloxacin and ciprofloxacin (17.8%) were the most common finding in broilers. Twenty-seven farms had 44 within-farm concordant patterns of resistance. From simulation, the frequency of concordance was significantly higher than concordance by chance alone (P < 0.05). Out of these 44 matched sets, only four had the same DNA fingerprint pattern. Concordance by DNA pattern was also not associated with phenotypic resistance. Clonal spread is therefore not a good explanation of the concordance in this population. Other mechanisms need further analysis.     

Preventive antibiotic treatment of calves: emergence of dysbiosis causing propagation of obese state-associated and mobile multidrug resistance-carrying bacteria

In agriculture, antibiotics are used for the treatment and prevention of livestock disease. Antibiotics perturb the bacterial gut composition but the extent of these changes and potential consequences for animal and human health is still debated. Six calves were housed in a controlled environment. Three animals received an injection of the antibiotic florfenicol (Nuflor), and three received no treatment. Faecal samples were collected at 0, 3 and 7 days, and bacterial communities were profiled to assess the impact of a therapy on the gut microbiota. Phylogenetic analysis (16S-rDNA) established that at day 7, antibiotic-treated microbiota showed a 10-fold increase in facultative anaerobic Escherichia spp, a signature of imbalanced microbiota, dysbiosis. The antibiotic resistome showed a high background of antibiotic resistance genes, which did not significantly change in response to florfenicol. However, the maintenance of Escherichia coli plasmid-encoded quinolone, oqxB and propagation of mcr-2, and colistin resistance genes were observed and confirmed by Sanger sequencing. The microbiota of treated animals was enriched with energy harvesting bacteria, common to obese microbial communities. We propose that antibiotic treatment of healthy animals leads to unbalanced, disease- and obese-related microbiota that promotes growth of E. coli carrying resistance genes on mobile elements, potentially increasing the risk of transmission of antibiotic resistant bacteria to humans.     

Herd prevalence of Enterobacteriaceae producing CTX‐M‐type and CMY‐2 β‐lactamases among Japanese dairy farms

Aims

To determine the herd prevalence of Enterobacteriaceae producing CTX‐M‐type extended‐spectrum β‐lactamases (ESBLs) among 381 dairy farms in Japan.

Methods and Results

Between 2007 and 2009, we screened 897 faecal samples using BTB lactose agar plates containing cefotaxime (2 μg ml^?1). Positive isolates were tested using ESBL confirmatory tests, PCR and sequencing for CTX‐M, AmpC, TEM and SHV. The incidence of Enterobacteriaceae producing CTX‐M‐15 (n = 7), CTX‐M‐2 (n = 12), CTX‐M‐14 (n = 3), CMY‐2 (n = 2) or CTX‐M‐15/2/14 and CMY‐2 (n = 4) in bovine faeces was 28/897 (3·1%) faecal samples. These genes had spread to Escherichia coli (n = 23) and three genera of Enterobacteriaceae (n = 5). Herd prevalence was found to be 20/381 (5·2%) dairy farms. The 23 E. coli isolates showed clonal diversity, as assessed by multilocus sequence typing and pulsed‐field gel electrophoresis. The pandemic E. coli strain ST131 producing CTX‐M‐15 or CTX‐M‐27 was not detected.

Conclusions

Three clusters of CTX‐M (CTX‐M‐15, CTX‐M‐2, CTX‐M‐14) had spread among Japanese dairy farms.

Significance and Impact of the Study

This is the first report on the prevalence of multidrug‐resistant CTX‐M‐15–producing E. coli among Japanese dairy farms.     

Study of CTX-M Type of Extended Spectrum β-Lactamase among Nosocomial Isolates of <Emphasis Type="Italic">Escherichia coli</Emphasis> and <Emphasis Type="Italic">Klebsiella pneumoniae</Emphasis> in South India

Data on CTX-M type extended-spectrum β-lactamase (ESBL) produced by Gram-negative bacteria by molecular methods are limited from India. This study was conducted to investigate the prevalence of CTX-M type ESBL producing Escherichia coli and Klebsiella pneumoniae from nosocomial isolates in a tertiary care hospital in southern India. A total of 179 clinical isolates of K. pneumoniae (n = 72) and E. coli (n = 107) were obtained in a period of 3 months and assessed for ESBL production phenotypically. Associated resistance to a panel of antibiotics and Minimum Inhibitory Concentration for 3rd generation cephalosporins was determined. Phenotypically ESBL positive isolates were subjected to PCR for bla _CTX-M gene using two sets of primers for the simultaneous detection of all the five major groups of CTX-M types. All the positive isolates were then subjected to a group specific PCR to detect the prevalent group. Out of 179 isolates, 156 (87.1%) were positive for ESBL phenotypically, which includes 39.2% of K. pneumoniae and 60.8% of E. coli. All of them were examined by PCR using two primers for the presence of bla _CTX-M genes. Among the 156 phenotypic positive isolates, 124 (79.4%) were positive for bla _CTX-M genes, of which 45 (36.2%) were K. pneumoniae, 79 (63.7%) were E. coli. When the 124 positive clinical isolates were further tested with CTX-M group-specific primers, all were positive for the CTX-M-1 group. Our findings document evidence of the high prevalence of multidrug resistant CTX-M group 1 type ESBL among nosocomial isolates in this region. High co-resistance to other non-β-lactam antibiotics is a major challenge for management of ESBL infections. This is alarming and calls for the judicious use of carbapenems, especially in developing countries. This has significant implications for patient management, and indicates the need for increased surveillance and for further molecular characterization of these isolates.     

Antimicrobial resistance in faecal enterococci and Escherichia coli isolates recovered from Iberian wolf

The aim of this study was to report the antimicrobial resistance, the molecular mechanisms associated and the detection of virulence determinants within faecal Enterococcus spp. and Escherichia coli isolates of Iberian wolf. Enterococci (n = 227) and E. coli (n = 195) isolates were obtained from faecal samples of Iberian wolf (Canis lupus signatus). High rates of resistance were detected for tetracycline and erythromycin among the enterococci isolates, and most of resistant isolates harboured the tet(M) and/or tet(L) and erm(B) genes, respectively. The bla_TEM, tet(A) and/or tet(B), and aadA or strA‐strB genes were detected among most ampicillin‐, tetracycline‐ or streptomycin‐resistant E. coli isolates, respectively. E. coli isolates were ascribed to phylogroups A (n = 56), B1 (91), B2 (13) and D (35). The occurrence of resistant enterococci and E. coli isolates in the faecal flora of Iberian wolf, including the presence of resistant genes in integrons, and virulence determinants was showed in this study. Iberian wolf might act as reservoir of certain resistance genes that could be spread throughout the environment.

Significance and Impact of the Study

This study shows antimicrobial resistance in commensal bacteria from the free‐range, Portuguese, Iberian wolf population. The results indicate that the Iberian wolf could contribute to the spread of resistant bacteria throughout the environment. Additionally, in case of infection, an increased risk of therapeutic failure due to the presence of multiresistant bacteria may represent a health problem for this endangered species. Future studies must be performed to analyse the possible contamination of these animals through the environment and/or the food chain.     

Genetic capitalism and stabilizing selection of antimicrobial resistance genotypes in Escherichia coli

Antimicrobial resistance (AMR) in pathogenic strains of bacteria, such as Escherichia coli (E. coli), adversely impacts personal and public health. In this study, we examine competing hypotheses for the evolution of AMR including (i) ‘genetic capitalism’ in which genotypes that confer antibiotic resistance are gained and not often lost in lineages, and (ii) ‘stabilizing selection’ in which genotypes that confer antibiotic resistance are gained and lost often. To test these hypotheses, we assembled a dataset that includes annotations for 409 AMR genotypes and a phylogenetic tree based on genome-wide single nucleotide polymorphisms from 29 255 isolates of E. coli collected over the past 134 years. We used phylogenetic methods to count the times each AMR genotype was gained and lost across the tree and used model-based clustering of the genotypes with respect to their gain and loss rates. We demonstrate that many genotypes cluster to support the hypothesis for genetic capitalism while a few genotypes cluster to support the hypothesis for stabilizing selection. Comparing the sets of genotypes that fall under each of the hypotheses, we found a statistically significant difference in the breakdown of resistance mechanisms through which the AMR genotypes function. The result that many AMR genotypes cluster under genetic capitalism reflects that strong positive selective forces, primarily induced by human industrialization of antibiotics, outweigh the potential fitness costs to the bacterial lineages for carrying the AMR genotypes. We expect genetic capitalism to further drive bacterial lineages to resist antibiotics. We find that antibiotics that function via replacement and efflux tend to behave under stabilizing selection and thus may be valuable in an antibiotic cycling strategy.     

Modulation of virulence and antibiotic susceptibility of enteropathogenic Escherichia coli strains by Enterococcus faecium probiotic strain culture fractions

The increasing rate of antimicrobial resistance drastically reduced the efficiency of conventional antibiotics and led to the reconsideration of the interspecies interactions in influencing bacterial virulence and response to therapy. The aim of the study was the investigation of the influence of the soluble and cellular fractions of Enterococcus (E.) faecium CMGB16 probiotic culture on the virulence and antibiotic resistance markers expression in clinical enteropathogenic Escherichia (E.) coli strains.The 7 clinical enteropathogenic E. coli strains, one standard E. coli ATCC 25,922 and one Bacillus (B.) cereus strains were cultivated in nutrient broth, aerobically at 37 °C, for 24 h. The E. faecium CMGB16 probiotic strain was cultivated in anaerobic conditions, at 37 °C in MRS (Man Rogosa Sharpe) broth, and co-cultivated with two pathogenic strains (B. cereus and E. coli O28) culture fractions (supernatant, washed sediment and heat-inactivated culture) for 6 h, at 37 °C. After co-cultivation, the soluble and cellular fractions of the probiotic strain cultivated in the presence of two pathogenic strains were separated by centrifugation (6000 rpm, 10 min), heat-inactivated (15 min, 100 °C) and co-cultivated with the clinical enteropathogenic E. coli strains in McConkey broth, for 24 h, at 37 °C, in order to investigate the influence of the probiotic fractions on the adherence capacity and antibiotic susceptibility. All tested probiotic combinations influenced the adherence pattern of E. coli tested strains. The enteropathogenic E. coli strains susceptibility to aminoglycosides, beta-lactams and quinolones was increased by all probiotic combinations and decreased for amoxicillin-clavulanic acid. This study demonstrates that the plurifactorial anti-infective action of probiotics is also due to the modulation of virulence factors and antibiotic susceptibility expression in E. coli pathogenic strains.     

Prevalence and antibiotic resistance of <Emphasis Type="Italic">Escherichia coli</Emphasis> in tropical seafood

Summary The occurrence and antibiotic resistance of Escherichia coli in tropical seafood was studied. A 3-tube MPN method was used for determining the level of faecal contamination of fresh and processed seafood. Of the 188 samples tested which included finfish, shellfish, water and ice, 155 were positive for the presence of faecal coliforms following incubation at 44.5 °C. However, E. coli was isolated from only 47% of the samples positive for faecal coliforms. The antibiotic resistance of 116 strains isolated from seafood was tested using 14 different antibiotics including ampicillin, cephalothin, chloramphenicol, ciprofloxacin, gentamycin, nalidixic acid, streptomycin and vancomycin. Seven strains were resistant to more than five antibiotics of which one was resistant to eight antibiotics. The multiple drug resistant strains harboured plasmids of varying sizes. Antibiotic susceptibility studies revealed that seafood from India contains multiple antibiotic resistant strains of E. coli which may serve as a reservoir for antibiotic resistance genes in the aquatic environment. All the strains used in this study did not harbour any virulence genes commonly associated with pathogenic E. coli, when tested by polymerase chain reaction (PCR).     

Antimicrobial resistance patterns among different Escherichia coli isolates in the Kingdom of Saudi Arabia

Antimicrobial resistance patterns among different Escherichia coli isolates in the Kingdom of Saudi Arabia. This study aimed to investigate the patterns of antimicrobial resistance in E. coli isolated from different samples, and to identify potential pathogenic isolates in Riyadh, Kingdom of Saudi Arabia (KSA). In total, 51 bacterial isolates were recovered from 113 samples of human urine, food (raw meat, raw chicken, raw egg surface, and fresh vegetables), water, and air. Twenty-four E. coli isolates were tested for susceptibility to 26 antibiotics. The air sample isolates were most resistant to amoxicillin, ampicillin, amoxicillin/clavulanic acid, amoxicillin/sulbactam, piperacillin/tazobactam, cefalotin, cefuroxime, cefoxitin, cefixime, nitrofurantoin, and trimethoprim/sulfamethoxazol. The isolates from vegetable samples were resistant to amoxicillin, ampicillin, amoxicillin/clavulanic acid, amoxicillin/sulbactam, cefalotin, cefuroxime, cefoxitin, and cefixime. By contrast, the isolates from the water samples were resistant only to amoxicillin and ampicillin. The isolates from the human urine samples were most frequently resistant to norfloxacin (80%) followed by amoxicillin and ampicillin (70%), trimethoprim/sulfamethoxazole (55%), ciprofloxacin and ofloxacin (50%), cefalotin (30%), cefuroxime, cefixime and cefotaxime (25%), ceftazidime, ceftriaxone, cefepime and aztreonam (20%), amoxicillin/clavulanic acid, piperacillin/tazobactam and gentamicin (10%), and amoxicillin/sulbactam and cefoxitin (5%). Almost all (23/25, 95.8%) (n = 23) of the isolates were multi-drug resistant (MDR) (i.e., resistant to 3 or more classes of antibiotics), and 16.7% (n = 4) of those were positive for extended spectrum β-lactamase (ESBL). Of the 4 ESBL-producers, 3 were positive for blaCTX_-M-15 and blaCTX_-M1_group, 2 were positive for blaCMY_-2, and 1 each was positive for blaCTX_{-M-2 group,} blaSHV, and blaOXA_-47. The quinolone resistance gene qnrS was detected in 25% (n = 6) of the E. coli strains isolated from urine (N = 5) and air (N = 1) samples. The considerable number of antimicrobial resistance genes detected among E. coli isolates tested here is alarming and should raise public health concern.     

Associations between intrauterine bacterial infection,reproductive tract inflammation,and reproductive performance in pasture-based dairy cows

Reproductive tract bacterial infections, particularly those caused by Escherichia coli and Trueperella pyogenes, can have a negative impact on reproductive performance. It has been hypothesized that the presence of E coli early postpartum may increase the risk of isolation of T pyogenes later postpartum. The objective of the present study was to examine associations between intrauterine bacterial infections with E coli and T pyogenes and any bacterial growth (irrespective of bacterial species), purulent vaginal discharge (PVD), cytologic evidence of endometritis (an increased proportion of polymorphonuclear cells [PMNs]), and reproductive performance. Dairy cows (n = 272) from six herds were examined at Days 0 (median, 2 days in milk), 21 and 42 postpartum. From each cow two intrauterine samples were collected via triple-guarded cytobrush at Days 0 and 21. The first cytobrush was used for bacteriologic culture. Escherichia coli and T pyogenes were isolated by culture, and E coli isolates were assigned to one of four phylogenetic groups using a two-step triplex polymerase chain reaction. In addition, T pyogenes was confirmed by polymerase chain reaction. The second cytobrush was used to prepare a cytology slide. Nucleated cells (n = 200) were categorized as epithelial cells, PMNs, or macrophages. Cows were also assessed for body condition score, PVD score, the presence of a CL, and pregnancy. Statistical analysis was performed using multivariable models. There was no association between the presence of E coli at Day 0 and probability of isolation of T pyogenes 3 weeks later; however, E coli positive cows at Day 0 were more likely to be diagnosed with E coli at Day 21 (relative risk [RR] = 2.0, P < 0.01). Escherichia coli at Day 0 or T pyogenes at Day 21 increased the risk of PVD diagnosis 3 weeks later (RR = 1.9; P = 0.04 and RR = 3.0; P = 0.05, respectively). Cows with any bacterial growth at Day 21, irrespective of species, were less likely to conceive within 3 weeks after the start of the seasonal breeding program (RR = 0.8; P = 0.05). Interestingly, cows with 25% PMNs or greater at Day 0 had shorter time to pregnancy (hazard ratio = 1.32; P = 0.05). Intrauterine bacterial infection may impair reproductive performance but the presence of E coli was not associated with isolation of T pyogenes 3 weeks later. Increased endometrial flux of PMNs in cows early postpartum may be a physiological process and improve reproductive performance.     

Antibiotic resistance in faecal bacteria (Escherichia coli,Enterococcus spp.) in feral pigeons

Aims: To determine the presence of antibiotic‐resistant faecal Escherichia coli and Enterococcus spp. in feral pigeons (Columba livia forma domestica) in the Czech Republic. Methods and Results: Cloacal swabs of feral pigeons collected in the city of Brno in 2006 were cultivated for antibiotic‐resistant E. coli. Resistance genes, class 1 and 2 integrons, and gene cassettes were detected in resistant isolates by polymerase chain reaction (PCR). The samples were also cultivated for enterococci. Species status of enterococci isolates was determined using repetitive extragenic palindromic‐PCR. Resistance genes were detected in resistant enterococci by PCR. E. coli isolates were found in 203 of 247 pigeon samples. Antibiotic resistance was recorded in three (1·5%, n_E. coli = 203) isolates. Using agar containing ciprofloxacin, 12 (5%, n_samples = 247) E. coli strains resistant to ciprofloxacin were isolated. No ESBL‐producing E. coli isolates were detected. A total of 143 enterococci were isolated: Ent. faecalis (36 isolates), Ent. faecium (27), Ent. durans (19), Ent. hirae (17), Ent. mundtii (17), Ent. gallinarum (12), Ent. casseliflavus (12) and Ent. columbae (3). Resistance to one to four antibiotics was detected in 45 (31%) isolates. Resistances were determined by tetK, tetL, tetM, tetO, aac(6′)aph(2′′), ant(4′)‐Ia, aph(3′)‐IIIa, ermB, pbp5, vanA and vanC1 genes. Conclusions: Antibiotic‐resistant E. coli and Enterococcus spp. occurred in feral pigeons in various prevalences. Significance and Impact of the Study: Feral pigeon should be considered a risk species for spreading in the environment antimicrobial resistant E. coli and enterococci.     

Hygienic quality and antibiotic resistance profile of sliced butchery

In order to investigate the microbiological quality of different meat products on the Greek market, 200 samples were collected from the following preparations: boiled turkey (n = 50), boiled pork ham (n = 50), smoked turkey (n = 50) and smoked pork ham (n = 50).In all cold meat preparations Clostridium perfringens vegetative and spore forms, Staphylococcus aureus, Escherichia coli and other Clostridium sp lec(-), as well as Lactobacillus, Bacillus sp. and Salmonella sp. were recovered. For instance Bacillus cereus was present in 6% of the samples.L. monocytogenes, Campylobacter jejuni and Campylobacter coli were rarely present (1–4%) while Yersinia enterocolitica and Campylobacter lari were absent. Differences in the occurrence of S. aureus, Salmonella sp., E. coli and spore forms of C. perfringens in boiled and smoked samples, reflects either the differences in the processing of the foods or could be associated to the extensive handling by the personnel during the purchasing (storage, slicing, wrapping).Antibiotic resistance on specific antibiotics for each pathogen was also studied. A multiresistance antibiotic profile was effective for most bacterial strains, and pronounced resistance profiles were observed for the commonly used antibiotics as ampicillin, penicillin, cephalothin, streptomycin followed by ceftriaxone and gentamycin. Albeit this high observed resistance profile, the tested strains generally conserved their susceptibility to amikacin, aztreonam, chloramphenicol and tylosin conserved an almost absent resistance. Antibiotics commonly used for therapeutic purposes, as well as antibiotics added to feed stuff of animals for increasing animal flesh production should contribute to the extensive spreading of antibiotic resistance in food and the environment.Systematically monitoring of the microbiological quality of cold butchery preparations must be done, in order to preserve food quality, optimizing the processing and elaboration methods of the product and safeguard the public health.     

Extended spectrum beta lactamases-producing Escherichia coli in retail chicken meat from Khyber Pakhtunkhwa,Pakistan

In human diet, poultry meat is an important component due to the presence of vitamins, proteins and minerals. But poultry meat can be contaminated by pathogenic bacteria which are responsible for food borne infections. The current study was therefore aimed at identification of Escherichia coli, a common pathogen causing food borne infections, in chicken samples (n = 400) collected from three districts of KhyberPukhtunkhwa; Peshawar, Kohat and Nowshera. The isolates were identified by Gram staining, API strips and through PCR (Universal Stress Protein). A total of 174 samples were positive for E. coli among the collected chicken samples. The isolates were resistant to TE, NOR and NA while were sensitive to MEM, TZP and FOS. The results were statistically significant having value P ≤ 0.05 in ANOVA. The isolates showed different antibiotic resistance genes; OXA-1, CTX-M15, blaTEM, QnrS, TetA, AAC, AAD, sul1 and sul2 which is the molecular explanations of their antibiotic resistance pattern. The PCR products were sequenced by Next Generation Sequencing (NGS) and the results revealed mutations in AAC gene (M120T and R197T) and CTX-M15 (A85V, N122D, A148S and G247D).To prevent and treat pathogenic diseases, the use of antimicrobial agents in animal husbandry are of utmost concern. The over-use and misuse of antimicrobial agents has made pathogenic E. coli multi drugs resistant making it a causative agent for many diseases in human beings. The results of the current study may be helpful for the physicians the better management of the diseases caused by E. coli.     

Dairy Farm Age and Resistance to Antimicrobial Agents in <Emphasis Type="Italic">Escherichia coli</Emphasis> Isolated from Dairy Topsoil

Antimicrobial agent usage is common in animal agriculture for therapeutic and prophylactic purposes. Selective pressure exerted by these antimicrobials on soil bacteria could result in the selection of strains that are resistant due to chromosomal- or plasmid-derived genetic components. Multiple antimicrobial resistances in Escherichia coli and the direct relationship between antimicrobial agent use over time has been extensively studied, yet the relationship between the age of an animal agriculture environment such as a dairy farm and antibiotic resistance remains unclear. Therefore, we tested the hypothesis that antimicrobial-resistance profiles of E. coli isolated from dairy farm topsoil correlate with dairy farm age. E. coli isolated from eleven dairy farms of varying ages within Roosevelt County, NM were used for MIC determinations to chloramphenicol, nalidixic acid, penicillin, tetracycline, ampicillin, amoxicillin/clavulanic acid, gentamicin, trimethoprim/sulfamethoxazole, cefotaxime, and ciprofloxacin. The minimum inhibitory concentration values of four antibiotics ranged 0.75 to >256 μg/ml, 1 to >256 μg/ml, 12 to >256 μg/ml, and 0.75 to >256 μg/ml for chloramphenicol, nalidixic acid, penicillin, and tetracycline, respectively. The study did not show a direct relationship between antibiotic resistance and the age of dairy farms.     

Antibiotics resistance of Helicobacter pylori in children with upper gastrointestinal symptoms in Hangzhou,China

Background

The decreasing eradication rate of Helicobacter pylori is mainly because of the progressive increase in its resistance to antibiotics. Studies on antimicrobial susceptibility of H. pylori in children are limited. This study aimed to investigate the resistance rates and patterns of H. pylori strains isolated from children.

Materials and Methods

Gastric mucosa biopsy samples obtained from children who had undergone upper gastrointestinal endoscopy were cultured for H. pylori, and susceptibility to six antibiotics (clarithromycin, amoxicillin, gentamicin, furazolidone, metronidazole, and levofloxacin) was tested from 2012‐2014.

Results

A total of 545 H. pylori strains were isolated from 1390 children recruited. The total resistance rates of H. pylori to clarithromycin, metronidazole, and levofloxacin were 20.6%, 68.8%, and 9.0%, respectively. No resistance to amoxicillin, gentamicin, and furazolidone was detected. 56.1% strains were single resistance, 19.6% were resistant to more than one antibiotic, 16.7% for double resistance, and 2.9% for triple resistance in 413 strains against any antibiotic. And the H. pylori resistance rate increased significantly from 2012‐2014. There was no significant difference in the resistance rates to clarithromycin, metronidazole, and levofloxacin between different gender, age groups, and patients with peptic ulcer diseases or nonulcer diseases.

Conclusions

Antibiotic resistance was indicated in H. pylori strains isolated from children in Hangzhou, and it increased significantly during the 3 years. Our data strongly support current guidelines, which recommend antibiotic susceptibility tests prior to eradication therapy.     

Home Ranges of Bottlenose Dolphins (<Emphasis Type="Italic">Tursiops truncatus</Emphasis>) in the Indian River Lagoon,Florida: Environmental Correlates and Implications for Management Strategies

Photo-identification surveys conducted between 2002 and 2005 were used to determine dolphin home ranges and site fidelity within the Indian River Lagoon (IRL), Florida. The IRL was divided into six segments based on hydrodynamics and geographic features for purposes of characterization. Among the 615 dolphins with identifiable dorsal fins, 339 had ≥6 sightings and were used in segment and linear range analyses. The majority (98%) of dolphins were seen in ≤3 consecutive segments (331/339); of these, 44% (144/331) occurred in two segments, and 33% (109/331) in one segment. No dolphins were observed in all six segments. The largest number of dolphins was sighted in segment 1C (North Indian River). However, the highest density of dolphins was found in segment 2 (North-Central Indian River). Re-sighting rates for dolphins with ≥6 sightings ranged from 2.8 to 8.7 times observed. The mean linear home range varied from 22 to 54 km. Distributional analyses indicated that at least three different dolphin communities exist within the IRL: Mosquito Lagoon, and the North and South Indian River. No statistically significant correlations were found between the total number or density per km² of dolphins and surface water area, salinity, or contaminant loads within segments of the lagoon. These results suggest that dolphins do not selectively avoid areas with relatively unfavorable water quality. IRL dolphins should be studied on smaller spatial scales than currently practiced, and potential anthropogenic impacts should be evaluated based on geographic partitioning.     

Antimicrobial Resistance and Spread of Multi Drug Resistant Escherichia coli Isolates Collected from Nine Urology Services in the Euregion Meuse-Rhine

We determined the prevalence and spread of antibiotic resistance and the characteristics of ESBL producing and/or multi drug resistant (MDR) Escherichia coli isolates collected from urine samples from urology services in the Euregio Meuse-Rhine, the border region of the Netherlands (n = 176), Belgium (n = 126) and Germay (n = 119). Significant differences in resistance between the three regions were observed. Amoxicillin-clavulanic acid resistance ranged from 24% in the Netherlands to 39% in Belgium (p = 0.018), from 20% to 40% (p<0.004) for the fluoroquinolones and from 20% to 40% (p = 0.018) for the folate antagonists. Resistance to nitrofurantoin was less than 5%. The prevalence of ESBL producing isolates varied from 2% among the Dutch isolates to 8% among the German ones (p = 0.012) and were mainly CTX-M 15. The prevalence of MDR isolates among the Dutch, German and Belgian isolates was 11%, 17% and 27%, respectively (p< = 0.001 for the Belgian compared with the Dutch isolates). The majority of the MDR and ESBL producing isolates belonged to ST131. This study indicates that most antibiotics used as first choice oral empiric treatment for UTIs (amoxicillin-clavulanic acid, fluoroquinolones and folate antagonists) are not appropriate for this purpose and that MDR strains such as CTX-M producing ST131 have spread in the entire Euregion. Our data stress the importance of ward specific surveillance to optimize empiric treatment. Also, prudent use of antibiotics and further research to alternative agents are warranted.     

Satellite tracking of gulls and genomic characterization of faecal bacteria reveals environmentally mediated acquisition and dispersal of antimicrobial‐resistant Escherichia coli on the Kenai Peninsula,Alaska

Gulls (Larus spp.) have frequently been reported to carry Escherichia coli exhibiting antimicrobial resistance (AMR E. coli); however, the pathways governing the acquisition and dispersal of such bacteria are not well described. We equipped 17 landfill‐foraging gulls with satellite transmitters and collected gull faecal samples longitudinally from four locations on the Kenai Peninsula, Alaska to assess: (a) gull attendance and transitions between sites, (b) spatiotemporal prevalence of faecally shed AMR E. coli, and (c) genomic relatedness of AMR E. coli isolates among sites. We also sampled Pacific salmon (Oncorhynchus spp.) harvested as part of personal‐use dipnet fisheries at two sites to assess potential contamination with AMR E. coli. Among our study sites, marked gulls most commonly occupied the lower Kenai River (61% of site locations) followed by the Soldotna landfill (11%), lower Kasilof River (5%) and upper Kenai River (<1%). Gulls primarily moved between the Soldotna landfill and the lower Kenai River (94% of transitions among sites), which were also the two locations with the highest prevalence of AMR E. coli. There was relatively high spatial and temporal variability in AMR E. coli prevalence in gull faeces and there was no evidence of contamination on salmon harvested in personal‐use fisheries. We identified E. coli sequence types and AMR genes of clinical importance, with some isolates possessing genes associated with resistance to as many as eight antibiotic classes. Our findings suggest that gulls acquire AMR E. coli at habitats with anthropogenic inputs and subsequent movements may represent pathways through which AMR is dispersed.