Occurrence Of Extended-spectrum Beta-lactamase Research Articles

Antibacterial Resistance and Extended-Spectrum Beta-Lactamase (ESBL) Phenotypes in Enterobacteriaceae Isolated from Fecal Samples of Humans and Animals in Selected Local Government Areas of Nasarawa State, Nigeria

It is quite alarming the increasing rate of antibacterial resistance all over the world considering the public health threat and the re-emergence of multi-drug resistant Enterobacteriaceae. The aim of this study is Antibacterial resistance and phenotypic detection of Extended Spectrum Beta-Lactamase (ESBL) producing Enterobacteriaceae isolated from human and animal fecal samples in selected local government areas of Nasarawa state, Nigeria was carried out in the study. Hundred (100) samples comprising human and animal (goats, cattle, and chicken) were collected and 55 samples were multidrug resistant. A commercial biochemical kit (Eneterosystem 18R) was used for the isolation and identification of Enterobacteriaceae. Kirby Bauer Disk Diffusion Method was used for antibacterial susceptibility testing of Enterobacteriaceae isolates. The Double Disc Synergy Test (DDST) method was also used for the phenotypic confirmation test of Extended Spectrum Beta Lactamase (ESBL). The occurrence of multidrug-resistant isolates shows that Escherichia coli (100.00%) which is the highest, Proteus mirabilis (14.54%), Klebsiella pneumoniae, and Salmonella enterica (10.90%), while the occurrence of Shigella flexneri (9.09%) was the lowest. The Enterobacteriaceae isolates were more resistant to Cefuroxime, Cefexime, Amoxicillin Clavulanate, and Imipenem/Cilastatin with percentage resistance ranges from 66.6% - 100%. The occurrence of ESBL producers shows that Escherichia coli (60.00%) and Proteus mirabilis (62.5%) were high while Shigella flexneri (20.0%) had a low occurrence of ESBL. The sale and in-discriminate use of antibiotics without a prescription is an important regulatory issue in the abuse of antibiotics for both humans and animals. The Beta-Lactam and gentamycin antibiotics were not effective against the Multi-Drug Resistant (MDR) isolates and most of the isolates were ESBL producers.

Unexpected role of pig nostrils in the clonal and plasmidic dissemination of extended-spectrum beta-lactamase-producing Escherichia coli at farm level

The presence of methicillin-resistant or -susceptible S. aureus in pig nostrils has been known for a long time, but the occurrence of extended-spectrum beta-lactamase (ESBL)-producing E. coli has hardly been investigated. Here, we collected 25 E. coli recovered from nasal samples of 40 pigs/10 farmers of four farms. Nine ESBL-producing isolates belonging to ST48, ST117, ST847, ST5440, ST14914 and ST10 were retrieved from seven pigs. All blaESBL genes (blaCTX-M-32,blaCTX-M-14,blaCTX-M-1,blaCTX-M-65, and blaSHV-12) were horizontally transferable by conjugation through plasmids belonging to IncI1 (n=3), IncX1 (n=3) and IncHI2 (n=1) types. IncI1-plasmids displayed different genetic environments: i) IS26-blaSHV-12-deoR-IS26, ii) wbuC-blaCTX-M-32-ISKpn26 (IS5), and iii) IS930-blaCTX-M-14-IS26. The IncHI2-plasmid contained the genetic environment IS903-blaCTX-M-65-fipA with multiple resistance genes associated either to: a) Tn21-like transposon harbouring genes conferring aminoglycosides/beta-lactams/chloramphenicol/macrolides resistance located on two atypical class 1 integrons with an embedded ΔTn5393; or b) Tn1721-derived transposon displaying an atypical class 1 integron harbouring aadA2-arr3-cmlA5-blaOXA-10-aadA24-dfrA14, preceding the genetic platform IS26-blaTEM-95-tet(A)-lysR-floR-virD2-ISVsa3-IS3075-IS26-qnrS1, as well as the tellurite resistance module. Other plasmids harbouring clinically relevant genes were detected, such as a ColE-type plasmid carrying the mcr-4.5 gene. Chromosomally encoded genes (fosA7) or integrons (intI1-dfrA1-aadA1-qacE-sul1/intI1-IS15-dfrA1-aadA2) were also identified. Finally, an IncY plasmid harbouring a class 2 integron (intI2-dfrA1-sat2-aadA1-qacL-IS406-sul3) was detected but not associated with a blaESBL gene. Our results evidence that pig nostrils might favour the spread of ESBL-E. coli and mcr-mediated colistin-resistance. Therefore, enhanced monitoring should be considered, especially in a sector where close contact between animals in intensive farming increases the risk of spreading antimicrobial resistance.

Occurrence of Extended-Spectrum Beta-Lactamase and Quinolone Resistance Genes among Escherichia coli and Klebsiella pneumoniae Isolated from Poultry, Domestic Pigs and Environ in Msimbazi River Basin in Tanzania

Occurrence of Extended-Spectrum Beta-Lactamase and Quinolone Resistance Genes among Escherichia coli and Klebsiella pneumoniae Isolated from Poultry, Domestic Pigs and Environ in Msimbazi River Basin in Tanzania

Antibacterial Resistance and Phenotypic Detection of Extended Spectrum Beta-Lactamase (ESBL) Producing Enterobacteriaceae Isolated from Environmental Sources in Nasarawa State, Nigeria

The multidrug resistant member of Enterobacteriaceae is common causes of community related infections. A study on antibacterial resistance and phenotypic detection of Extended Spectrum Beta-Lactamase (ESBL) producing Enterobacteriaceae isolated from environmental sources in Nasarawa state, Nigeria was carried out. A total of 400 samples comprised of air, water, soil, vegetable, and sewage were collected and 89 samples were multidrug resistant. Enterobacteriaceae were isolated and identified using commercial biochemical kit Eneterosystem 18R. The antibacterial susceptibility testing of Enterobacteriaceae isolates was carried out using the clinical and laboratory standards institute (CLSI). The phenotypic confirmation test of ESBL was carried out by double disc synergy test (DDST) method. The occurrence of multidrug resistant isolates shows that Escherichia coli (24.71%) and Klebsiella pneumoniae (19.10%) find to be high while the occurrence of Proteus mirabilis and Citrobacter freundii (6.74%) were low. The Enterobacteriaceae isolates were more resistant to Cefuroxime, Cefexime, Amoxicillin Clavulanate and Imipenem/Cilastatin with percentage resistance ranges from 62.5%–100%. The occurrence of ESBL producers shows that Klebsiella pneumoniae (66.7%) and Shigella flexneri (57.14%) were found to be high while the occurrence of ESBL was low in Proteus mirabilis (20.0%). The Beta Lactam and gentamycin antibiotics were not effective against the MDR isolates and most of the isolates were ESBL producers.

Occurrence of ESBL- and AmpC-Producing E. coli in French Griffon Vultures Feeding on Extensive Livestock Carcasses.

Despite the fact that the selective pressure of antibiotics on wild birds is supposed to be very weak, they are considered potential vectors of antimicrobial resistance (AMR). Obligate scavengers such as vultures can present high proportions of resistance to extended-spectrum cephalosporins (ESC) and multi-drug-resistant (MDR) bacteria, partially due to feeding stations that are provisioned with livestock carcasses from intensive farming. Here we investigated whether griffon vultures (Gyps fulvus) from two populations located in the French Alps, which feed on livestock carcasses from extensive farms, may carry such resistant bacteria. Phenotypic and genotypic characterization showed an 11.8% proportion of ESC-resistant bacteria, including five extended-spectrum beta-lactamase (ESBL)-producing and one AmpC-producing E. coli. The five ESBL-positive E. coli were clonal and all came from the same vulture population, proving their spread between animals. The ESBL phenotype was due to a blaCTX-M-15 gene located on the chromosome. Both ESBL- and AmpC-positive E. coli belonged to minor STs (ST212 and ST3274, respectively); interestingly, ST212 has already been identified in wild birds around the world, including vultures. These results suggest that actions are needed to mitigate the spread of MDR bacteria through wild birds, particularly in commensal species.

Antimicrobial resistance patterns and characterisation of emerging beta-lactamase-producing Escherichia coli in camels sampled from Northern Kenya.

Animal husbandry practices in different livestock production systems and increased livestock-wildlife interactions are thought to be primary drivers of antimicrobial resistance (AMR) in Arid and Semi-Arid Lands (ASALs). Despite a tenfold increase in the camel population within the last decade, paired with widespread use of camel products, there is a lack of comprehensive information concerning beta-lactamase-producing Escherichia coli (E. coli) within these production systems. Our study sought to establish an AMR profile and to identify and characterise emerging beta-lactamase-producing E. coli isolated from faecal samples obtained from camel herds in Northern Kenya. The antimicrobial susceptibility profiles of E. coli isolates were established using the disk diffusion method, with beta-lactamase (bla) gene PCR product sequencing performed for phylogenetic grouping and genetic diversity assessments. Here we show, among the recovered E. coli isolates (n = 123), the highest level of resistance was observed for cefaclor at 28.5% of isolates, followed by cefotaxime at 16.3% and ampicillin at 9.7%. Moreover, extended-spectrum beta-lactamase (ESBL)-producing E. coli harbouring the blaCTX-M-15 or blaCTX-M-27 genes were detected in 3.3% of total samples, and are associated with phylogenetic groups B1, B2 and D. Multiple variants of non-ESBL blaTEM genes were detected, the majority of which were the blaTEM-1 and blaTEM-116 genes. Findings from this study shed light on the increased occurrence of ESBL- and non-ESBL-encoding gene variants in E. coli isolates with demonstrated multidrug resistant phenotypes. This study highlights the need for an expanded One Health approach to understanding AMR transmission dynamics, drivers of AMR development, and appropriate practices for antimicrobial stewardship in camel production systems within ASALs.

Phenotypic screening of extended-spectrum beta-lactamase-producing Salmonella in retail shrimp

The occurrence of extended-spectrum beta-lactamase (ESBL) producing bacteria is concerning the scientific community since it confers multiple drug resistance (MDR). The study investigated the prevalence of MDR-ESBL-producing Salmonella strains from shrimp in Sylhet region, Bangladesh. A total of 165 shrimp samples were processed from 55 shrimp specimen from different retail shops. The presence of Salmonella was confirmed by standard methods followed by antibiotic susceptibility testing. Isolates exhibiting resistant to third-generation cephalosporin were considered as Salmonella positive isolates which was later proven by the double disc synergy test. Thirty-nine isolates were identified to be Salmonella positive of which eighteen were from seven department stores and twenty-one from the local market. The body parts had the highest rate of positive samples (30.91%), followed by the head (23.63%), and the tail (16.36%). Additionally, isolated Salmonella were resistant to rifampicin and Cefixime but 100% susceptible to co-trimoxazole, ofloxacin, streptomycin, nalidixic acid, and chloramphenicol, while ciprofloxacin showed intermediate resistance. Vancomycin, cephalexin, ampicillin, and colistin, on the other hand, were among the extremely resistant drugs. Finally, while six of the tested isolates demonstrated resistance against the recommended cephalosporin, three of them (7.69%) were Salmonella ESBL positive in the double disc synergy test. The rising incidence of MDR and the developing prevalence of ESBL-positive Salmonella may put a burden on the healthcare system by limiting access to effective antibacterial drugs.

EXTENDED SPECTRUM BETA-LACTAMASE (ESBL) PRODUCING PROTEUS SPECIES ISOLATED FROM CLINICAL SPECIMENS FROM SELECTED HOSPITALS IN JIGAWA STATE, NORTH-WEST NIGERIA

Proteus species are found in multiple environmental habitats, including long-term care facilities, hospitals, and can also cause both community and nosocomial infections. For a long time, Proteus was known to be susceptible to beta-lactam antibiotics but nowadays they become resistant. Hence, this study aims to determine the prevalence, antibiotic susceptibility pattern of extended spectrum beta lactamase (ESBL) producing Proteus species across Jigawa State, Northwest Nigeria. 1854 different clinical specimens were analysed of which 191 Proteus species were isolated through standard biochemical tests and used for this study from selected hospital between November, 2021 to August, 2022. Modified Kirby-Bauer disk diffusion method was used to test the susceptibility of the Proteus isolates to nine different antimicrobial agents. Double Disc Synergy Test (DDST) was used for phenotypic detection of ESBL in isolates. The prevalence of ESBL producing Proteus mirabilis was 11.8%. None of the Proteus vulgaris isolates in this study was found to be ESBL producers. Male patients were infected with more ESBL producers than those from female counterparts (Male vs Female; 12.5% vs 4.8%). Proteus mirabilis were observed to be significantly more susceptible to Ampicillin (P= 0.003), Gentamycin (P=0.024) and Cotrimoxazole (P=0.014). All ESBL producing Proteus mirabilis were resistant to three or more classes of antibiotics used in this study. This study reveals the occurrence of ESBL producing Proteus species in this environment. All the ESBL producing Proteus mirabilis encountered in this study exhibited multidrug resistance. Prudent use of antimicrobial agents is advocated in order to tame the trend.

Finding of extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales in wild game meat originating from several European countries: predominance of Moellerella wisconsensis producing CTX-M-1, November 2021.

IntroductionMeat can be a vehicle for food-borne transmission of antimicrobial resistant bacteria and antimicrobial resistance genes. The occurrence of extended-spectrum beta-lactamase (ESBL) producing Enterobacterales has been observed in meat from livestock production but has not been well studied in meat from wild game.AimWe aimed to investigate, particularly in central Europe, to what extent ESBL-producing Enterobacterales may be present in wild game meat.MethodsA total of 111 samples of different types of game meat supplied by butchers, hunters, retail stores and a large game-processing establishment in Europe were screened for ESBL-producing Enterobacterales using a selective culture medium. Isolates were genotypically and phenotypically characterised.ResultsThirty-nine samples (35% of the total) yielded ESBL-producing Enterobacterales, with most (35/39) supplied by the game-processing establishment. Isolates included 32 Moellerella wisconsensis, 18 Escherichia coli and one Escherichia marmotae. PCR screening identified bla CTX-M-1 (n = 31), bla CTX-M-32 (n = 8), bla CTX-M-65 (n = 4), bla CTX-M-15 (n = 3), bla CTX-M-8 (n = 1), bla CTX-M-14 (n = 1), bla CTX-M-55 (n = 1), and bla SHV-12 (n = 2). Most E. coli belonged to phylogenetic group A (n = 7) or B1 (n = 9), but several isolates belonged to extraintestinal pathogenic E. coli (ExPEC) sequence types (ST)58 (n = 4), ST68 (n = 1) and ST540 (n = 1). Whole genome sequencing of six selected isolates localised bla CTX-M-1 on megaplasmids in four M. wisconsensis and bla CTX-M-32 on IncN_1 plasmids in one M. wisconsensis and one E. marmotae. Forty-eight isolates (94%) exhibited a multidrug-resistance phenotype.ConclusionWe found a high occurrence of ESBL-producing Enterobacterales in wild game meat, suggesting wildlife habitat pollution and possible microbial contamination events occurring during skinning or cutting carcasses.

Occurrence of CTX-M, SHV and TEM β-lactamase genes in Extended Spectrum Beta-Lactamase (ESBL)- producing bacteria recovered from wastewater of a privately-owned hospital in Nigeria and a hand-dug well within its vicinity

BackgroundThe possibility of the dissemination of resistant bacteria and antimicrobials from healthcare facilities into shared environment is a threat to human health. This study investigated the occurrence of ESBL and AmpC β-lactamase genes in ESBL- producing bacteria isolated from wastewater of a privately-owned hospital in South-western Nigeria and underground water sources within its vicinity. MethodsHospital wastewater and water samples from borehole and hand-dug well, were collected over three months for the isolation of gram-negative bacteria. Phenotypic detection of ESBL production was done using the double disc synergy test (DDST), while characterization of positive isolates was done using API 20E identification kit. Susceptibility to antibiotics and detection of resistance genes were done using the disc diffusion method and Real-Time PCR respectively. Pulse field gel electrophoresis was used to determine the relationship between the isolates. ResultsSixteen ESBL- producing bacteria identified as Serratia fonticola (14), Enterobacter cloacae (1) and Pantoea agglomerans (1) were recovered. Resistance to ampicillin was 100%, ceftazidime (93.75%), amoxicillin-clavulanate (75.0%), trimethoprim-sulfamethoxazole (68.75%), gentamicin (50%), cefotaxime (43.75%), cefpodoxime (31.25%), ceftriaxone (18.75%) and 56.25% each to tetracycline and ciprofloxacin. No resistance was observed to cefoxitin. All the ESBL positive bacteria carried blaSHV, six carried blaSHV + blaTEM, while blaCTX-M-2, blaCTX-M-8 and blaCTX-M-25 were detected in three isolates. No isolate carried blaCTX-M-1, blaCTX-M-9, blaKPC, blaNDM-1, blaCMY-1 and ampC. All the ESBL- producing Serratia fonticola showed a high degree of genetic relatedness. ConclusionHospital wastewater and hand-dug wells in proximity to hospitals could be important reservoirs of ESBL- producing bacteria.

Occurrence of extended-spectrum beta-lactamase-producing Enterobacteriaceae, microbial loads, and endotoxin levels in dust from laying hen houses in Egypt

BackgroundPoultry houses are often highly contaminated with dust, which might contain considerable amounts of microorganisms and endotoxins. The concentrations of microorganisms and endotoxins in dust from laying hen houses in Egypt are unknown. However, to estimate the risks for birds, the environment, and people working in laying hen houses, it is important to gather information about the composition of these dusts. Here we report the microbial loads, the occurrence of antimicrobial-resistant bacteria, and endotoxin concentrations in dust samples from 28 laying hen farms in Dakahliya Governorate, Egypt, and discuss the results relevant to the literature.ResultsPooled settled dust samples (n = 28) were analyzed for total viable counts of bacteria and fungi (CFU/g), the occurrence of extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae, Salmonella spp., and methicillin-resistant Staphylococcus aureus (MRSA), and endotoxin concentrations (ng/g). The means and standard deviations of total viable counts were 7.10 × 108 ± 2.55 × 109 CFU/g for bacteria and 5.37 × 106 ± 7.26 × 106 CFU/g for fungi. Endotoxin levels varied from 2.9 × 104 to 6.27 × 105 ng/g. None of the tested samples contained Salmonella spp. or MRSA. In contrast, by direct plating, Enterobacteriaceae were found frequently (57%; n = 16), and suspected ESBL-producing Enterobacteriaceae occurred in 21% (n = 6) of the sampled barns. Using an enrichment method, the detection of Enterobacteriaceae and suspected ESBL-producing Enterobacteriaceae increased to 20 and 16 positive barns, respectively. Taking results from both methods into account, Enterobacteriaceae and suspected ESBL-producing Enterobacteriaceae were detected in 23 barns Overall, 100 ESBL suspected isolates (Escherichia coli, n = 64; Enterobacter cloacae, n = 20; and Klebsiella pneumoniae n = 16) were identified to species level by MALDI-TOF MS. Isolates from 20 barns (71% positive barns) were confirmed as ESBL producing Enterobacteriaceae by the broth microdilution test.ConclusionsDust in Egyptian laying hen houses contains high concentrations of microorganisms and endotoxins, which might impair the health of birds and farmers when inhaled. Furthermore, laying hens in Egypt seem to be a reservoir for ESBL-producing Enterobacteriaceae. Thus, farmers are at risk of exposure to ESBL-producing bacteria, and colonized hens might transmit these bacteria into the food chain.

Ocorrência de Escherichia coli e Klebsiella spp produtoras de ESBL em Hospital Universitário, na cidade de Manaus - AM

Justificativa e Objetivos:Bactérias produtoras de betalactamase de espectro ampliado (ESBL) são crescentes, sobretudo, pelo uso 
 rotineiro de antibióticos. Causam principalmente, infecções urinárias e de feridas operatórias e, caracterizam-se pela resistência às cefa-losporinas de terceira geração, aztreonam e associação de cefalosporinas com ácido clavulânico. Este estudo teve como objetivo conhecer 
 a frequência de Escherichia coli ESBL e Klebsiella spp.ESBL através da análise fenotípica. Métodos:Teste de sensibilidade in vitro por 
 aproximação de discos (CLSI), de bactérias isoladas de meios biológicos dos pacientes atendidos no HUGV entre 2017 e 2018. Resultados: 
 34,66% eram Escherichia coli ESBL e 46,80% Klebsiella spp.ESBL, totalizando 39,34% de amostras ESBL. Dos meios biológicos predomina-ram ESBL na: urina (56,25%) e feridas cirúrgicas (22,91%). Clínicas com maior ocorrência de ESBL: médica e cirúrgica. Conclusão: Os índices 
 de ESBL no HUGV estão próximos ou até mais altos do que em algumas regiões do país. Consoante a literatura revisada, predomina a 
 Escherichia coli nos isolados e há mais Klebisella spp. ESBL do queEscherichia coliESBL. 
 Descritores:Fenótipo. Escherichia coli. Klebsiella. ESBL. Infecção Hospitalar

Extended-spectrum beta-lactamase-producing Escherichia coli in chickens from small-scale (backyard) poultry farms in Maiduguri, Nigeria

Aim: This study investigated the occurrence of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli in chickens from small-scale (backyard) commercial poultry farms in Maiduguri. Materials and Methods: A total of 96 cloacal swab samples were collected. This comprised of 24 samples each from broiler chicks, pullets, layers, and broilers (adults). The samples were examined for the presence of E. coli using conventional microbiological culture and biochemical tests. The pure E. coli isolates were screened for ESBL production by culturing onto BrillianceTM ESBL agar. Isolates that showed positive reactions with production of bluish or pinkish colonies were tested for susceptibilities against some selected β-lactam antibiotics which include cefotaxime (30 μg), ceftriaxone (30 μg), cefpodoxime (10 μg), aztreonam (30 μg), and ceftazidime (30 μg). Isolates that exhibited resistance to any two or three of the antibiotics were selected and confirmed by combination disk diffusion method with ceftazidime (30 μg) and cefotaxime (30 μg) alone and in combination with clavulanic acid (30 μg/10 μg). Results: The total occurrence of E. coli was 67.6% (65/96) with the highest occurrence of 83.3% (20/24) from broiler chicks and least detection of 54.2% (13/24) from layers. Of this, 32.0% were ESBL-producing E. coli with the highest detection rate from layers (38.5%) and least occurrence from pullets (26.7%). Conclusion: This study revealed the presence of ESBL-producing E. coli in chickens from small-scale commercial poultry farms in Maiduguri, thus indicating that chickens may serve as important reservoirs for the transmission of antimicrobial resistant pathogens to humans through the food chain.

High resistance to tetracycline and ciprofloxacin in bacteria isolated from poultry farms in Ibadan, Nigeria.

Resistance to ciprofloxacin and tetracycline is increasing in the food chain especially in E. coli strains and more worrisome will be occurrence of extended-spectrum beta-lactamase (ESBL) producers among ciprofloxacin- and tetracycline-resistant isolates. This study was undertaken to investigate the occurrence and mechanism of ciprofloxacin-, tetracycline- and ESBL-resistant bacteria in poultry in Ibadan, Nigeria. Bacteria were isolated from poultry feces in two farms in Ibadan and identified by MALDI-TOF. Antibiotic susceptibility patterns of the isolates were determined by disc diffusion and Minimum Inhibitory Concentration (MIC) using Vitek-2 apparatus. Four tetracycline genes and six plasmids mediated quinolone resistance genes (PMQR) were investigated by PCR. Whole genome sequencing was done for strains that were ESBL producers. Bacterial strains (≥ 105 cfu/mL) were counted on ciprofloxacin and tetracycline supplemented plates. 106 bacteria from 14 different species were identified with high resistance to quinolones, tetracycline and trimethoprim. 49% of the strains were E. coli with 90% resistance for nalidixic acid, moxifloxacin (94%), ciprofloxacin (88%) levofloxacin (78%) and tetracycline (77%). The genes tetA, tetB, qnrB, qnrS and qepA were detected with 37%, 4%, 35%, 4% and 2% prevalence in E. coli respectively. Three ESBL-producing E. coli of the sequence type ST-6359 were found and harboured blaCTX-M-15 located in the chromosome, at the same insertion site. All the ESBL producers harboured mutations in gyrA (S83L/D87N/D678E) and parC (S80I). The observed high quinolones and tetracycline resistance with ESBL producers in this study calls for caution in the use of these antibiotics in poultry feeds.

Extended-Spectrum Beta-Lactamase-/AmpC Beta-Lactamase-Producing Enterobacteriaceae in Broiler Farms: Transmission Dynamics at Farm Level.

The occurrence of extended-spectrum beta-lactamase- (ESBL) and/or AmpC beta-lactamase- (AmpC) producing Enterobacteriaceae in livestock, especially in broiler fattening flocks, has been demonstrated in previous studies. Nevertheless, data on transmission routes of these resistant bacteria into the fattening farms are rare. Therefore, seven broiler fattening flocks were investigated for the occurrence of ESBL-/AmpC-producing Enterobacteriaceae during the course of the fattening period with the special focus on horizontal transmission routes. ESBL-/AmpC-producing Enterobacteriaceae from both individual animals and their housing environment were isolated at different time points and the housing environment was even sampled before the arrival of the chickens. All obtained ESBL-/AmpC-producing Enterobacteriaceae were examined for their bacterial species, Escherichia coli phylogroup, and occurrence of resistance genes. Selected isolates were further analyzed via whole-genome sequencing. All seven investigated flocks were tested positive for ESBL-/AmpC-producing Enterobacteriaceae with widely varying prevalence between the flocks. In one flock, the ESBL-/AmpC-producing Enterobacteriaceae were already detected in the housing environment before the arrival of the animals. In general, among the different types of ESBL-/AmpC-producing Enterobacteriaceae determined E. coli harboring a blaCMY-2 gene was the most frequent. Using whole-genome analyses we observed a horizontal transmission of ESBL-/AmpC-producing Enterobacteriaceae through contaminated housing environment as two flocks consecutively fattened in the same farm harbored closely related ESBL-producing isolates. This demonstrates the influence of a previous fattened flock on the ESBL-/AmpC-status of a following broiler flock and, therefore, the importance of hygiene measures on farm level.

EFSA's assistance for the 2015 Codex Committee on Residues of Veterinary Drugs in Food (CCRVDF) in relation to rBST

EFSA's assistance for the 2015 Codex Committee on Residues of Veterinary Drugs in Food (CCRVDF) in relation to rBST

Assessment of Adhesins as an Indicator of Pathovar-Associated Virulence Factors in Bovine Escherichia coli.

The CS31A, F17, and F5 adhesins are usually targeted by serology-based methods to detect pathogenic Escherichia coli associated with calf enteritis. However, the virulence traits of the selected isolates are still poorly described. Here, from a set of 349 diarrheagenic E. coli isolates from cattle, we demonstrated a 70.8% concordance rate (Cohen's kappa, 0.599) between serology- and PCR-based approaches for the detection of adhesins under field conditions. A 79% to 82.4% correspondence between the two methods was found for fimbrial adhesins, whereas major discrepancies (33%) were observed for CS31A-type antigens. Various F17A variants were found, such as F17Ac (20K) (50%), F17Aa (FY) (18.9%), F17Ab (8.1%), and F17Ad (111K) (5.4%), including a high proportion (17.6%) of new F17A internal combinations (F17Aab, F17Aac, and F17Abc) or untypeable variants. In addition, the highest proportion of pathovar-associated virulence factor (VF) genes was observed among E. coli isolates that produced F5/F41 adhesins. A specific link between the heat-stable toxins related to the enterotoxigenic E. coli (ETEC) pathovar and adhesins was identified. STa was significantly linked to F5/F41 and EAST1 to CS31A adhesins (P < 0.001), respectively, whereas NTEC was associated with F17 adhesin (P = 0.001). Clustering between phylogroups according to the adhesin types was also observed. Also, few Shiga toxin-producing E. coli (STEC) or enteropathogenic E. coli (EPEC) pathovars were identified. Finally, no statistically significant difference was observed in the occurrence of extended-spectrum beta lactamase (ESBL) production according to the adhesins expressed by the isolates (P = 0.09). Altogether, this study gives new insights into the relationship between adhesins, VF, and antimicrobial resistance in calf enteritis and supports the need for further standardization of methodologies for such approaches.

Occurrence of extended-spectrum b-lactamase producers among enterobacteriaceae in a paediatric tertiary care facility in Kabul.

The aim of this study was to determine the occurrence of extended spectrum beta-lactamase (ESBL)-producing species of Enterobacteriaceae to control their spread, from March 2008 to June 2012. A total of 411 ESBL-producing isolates were reported belonging to the family Enterobacteriaceae. There were 235 (57.18%) hospital-acquired infections (HAIs) and 176 (42.82%) community-acquired infections (CAIs). Out of total isolates, majority were E. coli (n=165, 40.15%), followed by 38.93% Klebsiella spp. (n=161), 9.97% Enterobacter spp. (n=41) and 6.33% Serratia spp. (n=26). Amongst HAIs, most frequent i.e., 111/235 (47.23%) were Klebsiella spp, whereas, amongst CAIs, majority i.e., 96/176 (54.55%) were E. coli. The frequency of ESBL-producing isolates from different sites was blood (37.71%), urine (29.93%), respiratory tract (18.49%) and other sites including pus/pus swabs, CSF/body fluids and secretions (13.87%) respectively. Majority of blood stream infections were caused by ESBL-producing Klebsiella species which accounted for 55.48% of all cases who had septicaemia, whereas E. coli was responsible for causing majority of urinary tract infections (UTIs) and accounted for 78% of all UTIs cases. Intensive Care Unit (ICU) was the place where majority of infections (55%) were observed, followed by 29% in the Medical Unit and 16% in the Surgical Unit.

Microbial resistance and frequency of extended-spectrum beta-lactamase (ESBL) in isolated from blood cultures

Introduction: The emergence and spread of isolated carriers of extended-spectrum beta-lactamase (ESBL) have complicated the treatment of nosocomial infections, since its production is not easily identified by the sensitivity tests, routinely performed in clinical laboratories, leading to difficulties in the hospital control of resistant microorganisms and antibiotics misuse. Objective: The objective of this study was to analyze the resistance profile and the frequency of ESBL in Gram-negative bacteria isolated from blood cultures. A hundred bacterial samples from blood cultures of adult patients were analyzed, which were phenotypically identified by biochemical tests of carbohydrates fermentation and submitted to determination of the resistance profile by disc diffusion test and ESBL screening by disc approximation and disc replacement methods. Results: Among the bacterial samples tested, 30 were identified as Gram-negative bacteria, predominantly by Proteus mirabilis, Pantoea agglomerans, and Escherichia coli. Of these, 73.33% were positive for the detection of ESBL by phenotypic tests, and was found mainly in Pantoea agglomerans, Proteus mirabilis, and Enterobacter cloacae. Conclusion: The increase in the occurrence of ESBL in different Enterobacteriaceae shows the importance of the amplification of detection in other species than Escherichia coli or Klebsiella sp., so that the assistance to the patient is not restrained, since these resistant bacteria cannot be detected by the laboratories. Considering the frequency of ESBL in this study, we highlight the importance of its detection, aiming to its contribution to the development of improvements in the health care policies of hospitals.

ESBL-Producing Enterobacteriaceae: Occurrence, Risk Factors for Fecal Carriage and Strain Traits in the Swiss Slaughter Cattle Population Younger than 2 Years Sampled at Abattoir Level

During the past decade extended-spectrum beta-lactamase (ESBL) producing Enterobacteriaceae have become a matter of great concern in human and veterinary medicine. In this cross-sectional study fecal swabs of a geographically representative number of Swiss cattle at slaughterhouse level were sampled i) to determine the occurrence of ESBL producing Enterobacteriaceae in the Swiss slaughter cattle population younger than 2 years, and ii) to assess risk factors for shedding ESBL producing Enterobacteriaceae. In total, 48 (8.4%; 95% C.I. 6.3–11.1%) independent ESBL producing Enterobacteriaceae were detected among the 571 tested animals. Species identification revealed 46 E. coli strains, one Enterobacter cloacae and one Citrobacter youngae. In view of beta-lactam antibiotics, all 48 isolates were resistant to ampicillin, cephalothin and cefpodoxime. Forty-five (93.8%) isolates were resistant cefuroxime; one (2.1%) isolate to cefoxitin, 28 (58.3%) isolates to cefotaxime, 2 (4.2%) isolates to ceftazidime, and 2 (4.2%) isolates to cefepime. Risk factors for shedding ESBL producing Enterobacteriaceae were (i) age (OR 0.19 and 0.12 in age category 181 d to 1y and 1y to 2 y compared to ≤180 d), (ii) primary production type, meaning dairy compared to beef on farm of origin (OR 5.95), and (iii) more than 1 compared to less than 1 animal movement per d per 100 animals on farm of origin (OR 2.37).