Multiple Antimicrobial Resistance Research Articles

Australian Group on Antimicrobial Resistance (AGAR) Australian Staphylococcus aureus Sepsis Outcome Programme (ASSOP) Annual Report 2019.

From 1 January to 31 December 2019, 39 institutions around Australia participated in the Australian Staphylococcus aureus Sepsis Outcome Programme (ASSOP). The aim of ASSOP 2019 was to determine the proportion of Staphylococcus aureus bacteraemia (SAB) isolates in Australia that are antimicrobial resistant, with particular emphasis on susceptibility to methicillin and on characterising the molecular epidemiology of the methicillin-resistant isolates. A total of 3,157 S. aureus bacteraemia episodes were reported, of which 79.8% were community-onset. 18.5% of S. aureus were methicillin resistant. The 30-day all-cause mortality associated with methicillin-resistant SAB was 14.0%, which was not significantly different from the 14.3% mortality associated with methicillin-susceptible SAB (p = 0.9). With the exception of the β-lactams and erythromycin, antimicrobial resistance in methicillin-susceptible S. aureus was rare. However, in addition to the β-lactams, approximately 36% of methicillin-resistant S. aureus (MRSA) were resistant to ciprofloxacin, 34% to erythromycin, 13% to tetracycline, 9% to gentamicin and 4% to co-trimoxazole. When applying the EUCAST breakpoints, teicoplanin resistance was detected in two S. aureus isolates. Resistance was not detected for vancomycin and linezolid. Resistance to non-beta-lactam antimicrobials was largely attributable to two healthcare-associated MRSA clones: ST22-IV [2B] (EMRSA-15) and ST239-III [3A] (Aus-2/3 EMRSA). ST22-IV [2B] (EMRSA-15) is the predominant healthcare-associated clone in Australia. Eighty percent of methicillin-resistant SAB, however, were due to community-associated clones. Although polyclonal, approximately 71.4% of community-associated clones were variously characterised as ST93-IV [2B] (Queensland CA-MRSA), ST5-IV [2B], ST45-VT [5C2&5], ST1-IV [2B], ST30-IV [2B], ST78-IV [2B] and ST8-IV [2B]. Community-associated MRSA (CA-MRSA), in particular the ST45-VT [5C2&5] clone, have acquired multiple antimicrobial resistance determinants including ciprofloxacin, erythromycin, clindamycin, gentamicin and tetracycline. The multiresistant ST45-VT [5C2&5] clone accounted for 12.7% of CA-MRSA. As CA-MRSA is well established in the Australian community, it is important that antimicrobial resistance patterns in community- and healthcare-associated SAB are monitored, as this information will guide therapeutic practices in treating S. aureus sepsis.

The determination of antimicrobial susceptibility by MIC and epidemiological cut-off values and the detection of resistance genes in Aeromonas species isolated from cultured fish.

The present study was aimed at determining antimicrobial susceptibility by a CLSI standard microdilution testing protocol and detecting the resistance genes of motile Aeromonas species isolated from cultured fish. The importance of the minimum inhibitory concentrations was assessed based on statistically determined epidemiological cut-off values calculated by normalized resistance analysis. Unfortunately, CLSI epidemiological cut-off values are available only for Aeromonas salmonicida, and there is no further detailed data on Aeromonas isolated from aquatic animals. The antimicrobial susceptibilities of pre-identified motile Aeromonas species to florfenicol, tetracycline and sulfamethoxazole were determined by calculating epidemiological cut-off values with fully automated and freely available Excel spreadsheets, applying the normalized resistance interpretation (NRI) method. Furthermore, the presence of the antimicrobial resistance genes floR, tetA, tetB, tetC, tetD, tetE, tetH, sulI, sulII and sulIII was detected by PCR analysis and confirmed by sequence analysis. The presence of up to six different genes (multiple antimicrobial resistance) was determined in the Aeromonas isolates. SIGNIFICANCE AND IMPACT OF THE STUDY: Significance and Impact of the Study: In this study, we investigated phenotypic and genotypic antimicrobial resistance characteristics by a novel method based on epidemiological cut-off values. This is the second comprehensive study on the antimicrobial susceptibility characteristics of Aeromonas species using NRI and epidemiological cut-off values. The present research is related to our previous researches focussed on the identification of motile Aeromonads, their prevalence in relation to different fish lengths, seasons and regions, and covered the investigation of Lactococcus garvieae, Yersinia ruckeri, Flavobacterium spp., Enterobacter spp. and Citrobacter spp.

Coinfection with Human Norovirus and Escherichia coli O25:H4 Harboring Two Chromosomal blaCTX-M-14 Genes in a Foodborne Norovirus Outbreak in Shizuoka Prefecture, Japan

Hospital-acquired infections caused by extended-spectrum β-lactamase (ESBL)-producing Escherichia coli are a global problem. Healthy people can carry ESBL-producing E. coli in the intestines; thus, E. coli from healthy people can potentially cause hospital-acquired infections. Therefore, the transmission routes of ESBL-producing E. coli from healthy persons should be determined. A foodborne outbreak of human norovirus (HuNoV) GII occurred at a restaurant in Shizuoka, Japan, in 2018. E. coli O25:H4 was isolated from some of the HuNoV-infected customers. Pulsed-field gel electrophoresis showed that these E. coli O25:H4 strains originated from one clone. Because the only epidemiological link among the customers was eating food from this restaurant, the customers were concurrently infected with E. coli O25:H4 and HuNoV GII via the restaurant food. Whole genome analysis revealed that the E. coli O25:H4 strains possessed genes for regulating intracellular iron and expressing the flagellum and flagella. Extraintestinal pathogenic E. coli often express these genes on the chromosome. Additionally, the E. coli O25:H4 strains had plasmids harboring nine antimicrobial resistance genes. These strains harbored ESBL-encoding blaCTX-M-14 genes on two loci of the chromosome and had higher ESBL activity. Multilocus sequence typing and fimH subtyping revealed that the E. coli O25:H4 strains from the outbreak belonged to the subclonal group, ST131-fimH30R, which has been driving ESBL epidemics in Japan. Because the E. coli O25:H4 strains isolated in the outbreak belonged to a subclonal group spreading in Japan, foods contaminated with ESBL-producing E. coli might contribute to spreading these strains among healthy persons. The isolated E. coli O25:H4 strains produced ESBL and contained plasmids with multiple antimicrobial resistance genes, which may make it difficult to select antimicrobials for treating extraintestinal infections caused by these strains.

Prevalence of Salmonella serotypes S. Enteritidis and S. Typhimurium in poultry and poultry products

AbstractSalmonella continues to be a major food safety and public health threat. In the present study, Salmonella enterica subsp. enterica serotypes Enteritidis (SE) and Typhimurium (ST) were isolated from poultry and characterized for virulence, antimicrobial susceptibility, and biofilm formation. Prevalence of Salmonella serotypes in poultry was 3.35%; predominant serotypes isolated were S. Enteritidis (68.1%) and S. Typhimurium (31.8%). Source‐wise, Salmonella were isolated from retail market chicken meat (4.8%), live chicken at farm (2.5%), and table eggs (2.1%). Salmonella isolates produced invA gene of 284 bp (100%), spvR gene of 310 bp (77.27%), spvC gene of 571 bp (22.72%), and stn gene of 260 bp (100%) as virulence/ pathogenicity determinants. Salmonella isolates exhibited resistance to common antimicrobials; 72.7% isolates showed multiple resistance (≥3 antimicrobial class), highest resistance was observed for polymyxin‐B (81.8%) followed by nalidixic acid (72.7%), colistin (59.1%), ampicillin/tetracyline (45.5%), ampicillin + sulbactam (40.9%), cefodroxil (18.2%), streptomycin (9.1%), and cefazidine/ceftriaxone‐tazobactam (4.5%). Multiple antimicrobial resistance (MAR) index of poultry Salmonella isolates ranged from 0.11 to 0.35; wherein, 59.1% isolates showed MAR of >0.2. About 81.8% Salmonella isolates produced biofilm and were categorized as strong (13.6%), moderate (45.4%), and weak (22.7%) biofilm producers. Occurrence of antimicrobial resistant virulent Salmonella strains in poultry requires implementation of suitable strategies so as to protect the public health.

Characterization of Salmonella spp. isolated from chickens in Central China

BackgroundSalmonella is an important zoonotic pathogen, and chickens are one of its main hosts. Every year, Salmonella infections pose a serious threat to the poultry industry in developing countries, especially China. In this study, a total of 84 Salmonella isolates recovered from sick and healthy-looking chickens in central China were characterized by serotyping, MLST-based strain typing, presence of potential virulence factors, and antimicrobial resistance profiles.ResultData showed that the main serotypes of Salmonella isolates in central China were Salmonella enterica serovar Gallinarum biovar Pullorum, Salmonella enterica serovar Gallinarum biovar Gallinarum, Salmonella enterica serovar Enteritidis and Salmonella enterica serovar Typhimurium, and among them, S. Pullorum was the dominant type in both sick and healthy-looking chickens, accounting for 43.9 and 46.5%, respectively, while S. Enteritidis was only found in healthy-looking chickens. All isolates exhibited higher resistance rates to ampicillin (97.6%), tetracycline (58.3%) and colistin (51.2%), and among these isolates, 49.5% were resistant to more than three drugs in different combinations. S. Enteritidis was the most severe multidrug-resistant serotype, which showed higher resistance rates to colistin, meropenem and ciprofloxacin. Multilocus sequence typing (MLST) revealed that S. Gallinarum and S. Enteritidis isolates were clustered in clade 1, which belonged to two and one STs, respectively. All S. Typhimurium isolates were clustered in clade 3, and belonged to three STs. However, S. Pullorum were distributed in three clades, which belonged to 7 STs. Twenty-seven virulence-associated genes were detected, and expected cdtB, which was absent in all the isolates, the other 26 genes were conserved in the closely related Salmonella serogroup D (S. Enteritidis, S. Pullorum, and S. Gallinarum).ConclusionSalmonella serogroup D was the major subgroup, and S. Pullorum was the most common type in sick and healthy-looking chickens in central China. Drug resistance assays showed serious multiple antimicrobial resistances, and S. Enteritidis was the most severe drug-resistant serotype. MLST showed that there was correlation between serotypes and genotypes in most Salmonella isolates, except S. Pullorum, which showed complicated genetic diversity firstly. These results provide important epidemiological information for us to control Salmonella in chickens.

Antimicrobial resistance profile of non-aureus Staphylococci isolates from buffalo, goat and sheep mastitis in the Northeast region of Brazil.

The study described in this Research Communication investigated the genotypic and phenotypic profiles of resistance to beta-lactams and other antimicrobials in non-aureus Staphylococci (NAS) isolated from buffalo, goat and sheep mastitis in the Northeast region of Brazil. A total of 190 isolates were analyzed and 42.3, 43.9 and 23.6% of them were positive for blaZ gene in buffalo, goat and sheep, respectively. Regarding the animal groups, in goats, amoxicillin was the antimicrobial with highest resistance index (72.7%), followed by penicillin G in buffaloes (51.9%) and ampicillin in sheep (43.1%). With regard to multiple antimicrobial resistance, 30.8% of NAS isolates from buffalo milk samples, 25.8% from goats and 25.0% from sheep presented multidrug-resistance. In the minimum inhibitory concentration (MIC) technique, amoxicillin MIC50 and MIC90 were 64 and 128 μg/ml, respectively, among isolates of the three animal species. In conclusion, high rates of resistance to beta-lactams are presented among NAS isolated from mastitis cases in buffaloes, goats and sheep in Northeast region of Brazil. These results provide an alert to animal and human health researchers, suggesting that the frequency of NAS needs to be reduced because they carry resistance genes which might increase the existing levels of antimicrobial resistance.

Predicting β-lactam resistance using whole genome sequencing in Klebsiella pneumoniae: the challenge of β-lactamase inhibitors

Although multiple antimicrobial resistance (AMR) determinants can confer the same in vitro antimicrobial susceptibility testing (AST) phenotype, their differing effect on optimal therapeutic choices is uncertain. Using a large population-based collection of clinical strains spanning a 3.5-year period, we applied WGS to detect inhibitor resistant (IR), extended-spectrum β-lactamase (ESBL), and carbapenem resistant (CR) β-lactamase (bla) genes and compared the genotype to the AST phenotype in select isolates. All blaNDM-1 (9/9) and the majority of blaNDM-1/OXA-48 (3/4) containing isolates were resistant to CAZ/AVI as predicted by WGS. The combination of ATM and CAZ/AVI restored susceptibility by disk diffusion assay. Unexpectedly, clinical Kp isolates bearing blaKPC-8 (V240G) and blaKPC-14 (G242 and T243 deletion) did not test fully resistant to CAZ/AVI. Lastly, despite the complexity of the β-lactamase background, CAZ/AVI retained potency. Presumed phenotypes conferred by AMR determinants need to be tested if therapeutic decisions are being guided by their presence or absence.

Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA) in drinking water fountains in urban parks

The presence of Staphylococcus aureus in drinking water is a concern because of its potential to cause human infection and also because of its multiple antimicrobial resistance. This study evaluated the water quality of drinking water fountains and mist makers in four municipal parks of São Paulo for 13 months. Although all samples met bacteriological water quality criteria according to Brazilian regulations, the absence of residual chlorine (<0.1 mg/L) was observed. These data were significantly correlated with the frequency of S. aureus that was found in 25.2% of the samples. The mecA gene was detected in 36.7% of the isolates demonstrating its potential for resistance to several antimicrobials. Furthermore, 27.3% isolates carrying the mecA gene had methicillin-resistant Staphylococcus aureus (MRSA) phenotypic potential. The presence of S. aureus with characteristics of microbial resistance in water for human consumption is an unprecedented finding. Hence, conducting surveillance for opportunistic bacteria, such as staphylococci in drinking water, is reasonable to take control measures and to protect human health, especially in public places with high attendance.

Antimicrobial Resistance Profile of Escherichia coli Isolates from Different Clinical Samples in Abeokuta, Ogun State

The alarming increase of antibiotic resistance of Escherichia coli has posed a great challenge in the public health sector. Thus, this microorganism is a leading cause of different human infections and it can be found in various environments. The aim of this study is to investigate the antimicrobial susceptibility patterns and the multiple antimicrobial resistance profile of Escherichia coli isolates obtained from some hospitals in Abeokuta, Ogun State, Nigeria. Isolates of E. coli were obtained from different clinical samples and were re-identified morphologically and biochemically. E. coli was isolated from 30% out of a total of 70 clinical samples analyzed for isolation and identification. The isolation rate of E. coli was highest in urine samples 10(47.6%) when compared to other clinical samples. There was significant increase in the resistance rate of E. coli to tetracycline (14.3%), ceftazidime (14.2%), and ampicillin (14.2%).Also, an increased sensitivity rate to augmentin (71.4%), ofloxacin (66.7%), cefuroxime (66.7%), ciprofloxacin (61.9%) and ceftazidime (61.9%) were observed. Furthermore, the overall multiple drug resistance rates obtained was 14(66.7%) and it was established that, multiple antimicrobial resistance of the E. coli isolates was plasmid mediated. E. coli isolates exhibited high resistance rate to multiple antimicrobial agents, however, its sensitivity to augmentin, ofloxacin, cefuroxime, ciprofloxacin and ceftazidime showed that these antimicrobials are still effective against E. coli infections in the study area.

Closed Genome Sequences and Antimicrobial Resistance Profiles of Eight Wild Bird Salmonella Isolates Obtained with MinION and Illumina MiSeq Sequencing.

Complete genome sequences of eight isolates of Salmonella enterica subsp. enterica from Canadian wild birds were determined by MinION and Illumina MiSeq sequencing. Assembled chromosomes had an average size of 4,833,662 bp. Salmonella enterica serovar Worthington obtained from partridge and quail carried 267-kb plasmids, which contained multiple antimicrobial resistance genes.

Genome sequences of two Salmonella enterica strains (MEZSAL74 and MEZSAL81) harbouring multiple antimicrobial resistance genes isolated from livestock in South Africa

ObjectivesAntimicrobial-resistant livestock-associated Salmonella enterica infections pose a significant public-health threat worldwide. Here we report for the first time the draft genome sequences of two multidrug-resistant livestock-associated S. enterica strains isolated from a chicken and a cow in South Africa. MethodsGenomic DNA of S. enterica strains MEZSAL74 and MEZSAL81 was sequenced using an Illumina MiSeq platform. The generated reads were trimmed and de novo assembled. The assembled contigs were analysed for antimicrobial resistance genes, chromosomal mutations and extrachromosomal plasmids. Multilocus sequence typing (MLST) was also performed. In order to compare isolates MEZSAL74 and MEZSAL81 with other previously sequenced S. enterica isolates, raw read sequences were downloaded and all sequence files were treated identically to generate a bootstrapped maximum likelihood phylogenetic tree. ResultsExtrachromosomal plasmids and genetic determinants of antimicrobial resistance were detected in both sequenced bacterial isolates to aminoglycosides and fluoroquinolones. By MLST, strain MEZSAL74 belonged to an unknown sequence type (ST) and strain MEZSAL81 belonged to ST33. ConclusionThe genome sequences of strains MEZSAL74 and MEZSAL81 reported here will serve as a reference for molecular epidemiological studies of antimicrobial-resistant livestock-associated S. enterica in Africa.

Emergence of Escherichia coli ST131 Causing Urinary Tract Infection in Western Asia: A Systematic Review and Meta-Analysis.

Escherichia coli sequence type (ST) 131 is considered a high-risk pandemic clone and frequently extended-spectrum β-lactamase (ESBL)-producing clone that is strongly associated with the global dissemination of CTX-M-15 type. The emergence of ST131 has become a public health threat because this clonal group typically exhibits multiple virulence factors and antimicrobial resistance. Therefore, this study aimed to analyze the literature published on the estimation of the prevalence of clone ST131 among E. coli strains isolated from patients with urinary tract infections in western Asia. A systematic search was carried out to identify eligible articles in the Web of Science, PubMed, Scopus, Embase, and Google Scholar electronic databases from January 2010 to December 2018. Next, 13 articles meeting the inclusion criteria were selected for data extraction and analysis by Comprehensive Meta-Analysis Software. The included studies were conducted in Iran, Jordan, Kuwait, Pakistan, Saudi Arabia, Turkey, and Yemen. In all studies, the pooled prevalence of ST131 was 24.6% (95% CI: 13.5%-40.4%) in wild type isolates, 42.7% (95% CI: 32.5%-53.5%) among ESBLs-producing isolates, and 64.8% (95% CI: 36%-85.5%) among multiple-drug resistant (MDR) isolates. Moreover, the prevalence of ST131 isolates carrying CTX-M-15 type was 68% (95% CI: 48.4%-82.8%). Our study indicated the high prevalence of broadly disseminated ST131 clone among MDR and ESBLs isolates in western Asia. Moreover, O25b was the predominant ST131 clone type, which was mostly associated with CTX-M-15 type.

Antimicrobial Resistance and Extended-Spectrum Beta-Lactamase Production in Enterobacteria Isolated from Free-Living Primates.

The aim of this study was to evaluate the profile of antimicrobial resistance in members of the family Enterobacteriaceae and to detect strains of extended-spectrum beta-lactamases (ESBL) in free-living Sapajus nigritus. Oral and rectal swabs were collected from 15 primates to isolate and identify bacteria, conduct phenotypic tests to detect antimicrobial sensitivity and ESBL-producing strains, and calculate the multiple antimicrobial resistance index. The least effective antimicrobial was amoxicillin (72.72%) and ampicillin (57.57%), and the samples were considered as high risk for public health. No sample was positive for ESBL production. The results show that this study is relevant to One Health initiatives, considering the possibility of transmission of bacterial resistance and resistant genes originating from direct or indirect interaction of S. nigritus with parkgoers. However, these animals cannot be considered as the only reservoirs and transmitters of resistant bacteria as they can be contaminated by human-origin bacteria that can be extremely harmful and often prove lethal to them that play an important role in relationship to the ecology, spreading seeds and controlling insects.

Aeromonas spp. Isolated from Pacific Abalone (Haliotis discus hannai) Marketed in Korea: Antimicrobial and Heavy-Metal Resistance Properties.

Antimicrobial and heavy-metal resistance of 29 Aeromonas spp. (Aeromonas hydrophila n = 9, Aeromonas enteropelogenes n = 14, Aeromonas veronii n = 3, Aeromonas salmonicida n = 2, and Aeromonas sobria n = 1) isolated from Pacific abalone marketed in Korea were analyzed. All isolates were found to be resistant against ampicillin. High level of resistant to cephalothin (86%), rifampicin (73%), imipenem (42%), and oxytetracycline (35%) were also detected. Thirteen (45%) of the isolates showed multiple antimicrobial resistance (MAR) index ≥ 0.2. The PCR assays implied the presence of qnrS, qnrB, qnrA, tetB, tetA, aac (3')- IIa, aac(6')-Ib, aphAI-IAB, blaCTX, blaTEM, and intI1 genes among 76%, 28%, 14%, 17%, 3%, 3%, 41%, 10%, 41%, 28%, and 66% of the isolates, respectively. Class 1 integron gene cassette profiles aadA1(3%) and aadA2 (3%) were also identified. Lead (Pb) resistance was the highest (69%) among 5 heavy metals tested, whereas 38%, 27%, and 20% of the isolates were resistant to Cadmium (Cd), Chromium (Cr), and Copper (Cu), respectively. Heavy-metal resistance genes, CopA, CzcA, and merA were positive in 83%, 75%, and 41% of the isolates, respectively. In conclusion, observed genotypic and phenotypic resistance profiles of Aeromonas spp. against antimicrobials and heavy metals reveal the ability of serving as a source of antimicrobials and heavy-metal-resistant traits.

First Report of the Local Spread of Vancomycin-Resistant Enterococci Ascribed to the Interspecies Transmission of a vanA Gene Cluster-Carrying Linear Plasmid.

Vancomycin-resistant enterococci pose a threat in the clinical setting and have been linked to hospital outbreaks worldwide. In 2017, a local spread of VanA-type vancomycin-resistant enterococci (VRE) occurred in Japan, and 25 enterococcal isolates, including 14 Enterococcus faecium, 8 E. raffinosus, and 3 E. casseliflavus isolates, were identified from four inpatients. Molecular analysis of the multispecies of VanA-type VRE revealed the involvement of both the dissemination of clonally related VRE strains between patients and the horizontal transfer of plasmids harboring the vanA gene cluster between Enterococcus spp. Pulsed-field gel electrophoresis showed that the plasmid DNAs without S1 nuclease treatment were able to migrate into the gel, suggesting that the topology of the plasmid was linear. Whole-genome sequencing revealed that this plasmid, designated pELF2, was 108,102 bp long and encoded multiple antimicrobial resistance genes, including ermA and ant(9). The amino acid sequences of putative replication- and transfer-related genes were highly conserved between pELF2 and pELF1, the latter of which was the first identified enterococcal conjugative linear plasmid. On comparing the genomic structure, pELF2 showed the presence of a backbone similar to that of pELF1, especially with respect to the nucleotide sequences of both terminal ends, indicating a hybrid-type linear plasmid, possessing two different terminal structures. pELF2 possessed a broad host range and high conjugation frequencies for enterococci. The easy transfer of pELF2 to different Enterococcus spp. in vitro might explain this local spread of multiple species, highlighting the clinical threat from the spread of antimicrobial resistance by an enterococcal linear plasmid.IMPORTANCE Increasing multidrug resistance, including vancomycin resistance, in enterococci is a major concern in clinical settings. Horizontal gene transfer, such as via plasmids, has been shown to play a crucial role in the acquisition of vancomycin resistance. Among vancomycin resistance types, the VanA type is one of the most prevalent, and outbreaks caused by VanA-type vancomycin-resistant enterococci (VRE) have occurred worldwide. Here, we describe an enterococcal linear plasmid responsible for multispecies local spread of VanA-type VRE. Such a study is important because although hospital outbreaks caused by mixed enterococcal species have been reported, this particular spread indicates plasmid transfer across species. This is a crucial finding because the high risk for such a spread of antimicrobial resistance calls for regular monitoring and surveillance.

CHARACTERISATION OF PATHOGENIC VIBRIO SPP. ISOLATED FROM LIVE PACIFIC ABALONE (HALIOTIS DISCUS HANNAI INO, 1953) MARKETED IN SOUTH KOREA

This study aimed to evaluate the profile of virulence factors and antimicrobial resistance in Vibrio spp. isolated from live Pacific abalone (Haliotis discus hannai Ino, 1953) marketed in South Korea. A total of 32 Vibrio isolates comprising V. alginolyticus (n=15), V. diabolicus (n=14), V. antiquarius (n=2) and V. parahaemolyticus (n=1) were analysed. All isolates demonstrated DNase, lipase, phospholipase and amylase activities. Additionally, production of slime (97%), gelatinase (94%), α-haemolysin (22%), β-haemolysin (78%) and protease (53%) were detected. Virulence genes viz., toxR, tlh, tdh, VAC, VPI, ctxAB and hupO were recorded in 56, 59, 13, 100, 41, 9 and 9% of the isolates, respectively. All isolates were resistant to ampicillin and 88% of the isolates were resistant to cephalothin and colistin sulphate. Twentyone isolates (66%) showed multiple antimicrobial resistance (MAR) index ≥0.2. Antimicrobial resistance genes blaCTX (85%), blaTEM (10%), blaSHV (10%), strAB (13%) and aphA-IAB (22%) and class 1 integrons (19%) were detected. V. diabolicus and V. antiquarius were identified and characterised for the first time in the Pacific abalone. Our findings imply the significance of integrated monitoring and surveillance programmes for the occurrence, virulence, and antimicrobial resistance patterns of vibrios in Pacific abalone.

Novedades en el diagnóstico y tratamiento de la infección de tracto urinario en adultos

Descripción resumida del tema: Las infecciones del tracto urinario (ITU) engloban cualquier infección que involucre las vías urinarias. Es una patología frecuente en los servicios de hospitalización y ambulatorios, lo que hace indispensable tener conocimiento de los grupos de riesgo, la causalidad, para ofrecer prevención en los pacientes que lo ameriten, protocolos de seguimiento, entender quién realmente requiere estudios de extensión y medidas más especializadas.&#x0D; Relevancia: Al ser una condición clínica tan común, no es suficiente con lograr su identificación y tratamiento, sino que obliga al personal de la salud a estar atento ante condiciones que requieran un cuidado especial y tratamientos oportunos. En los casos en que puede ser manejado de manera más específica se debe ser muy razonable con los tratamientos antibióticos para evitar las resistencias antimicrobianas.&#x0D; Conclusiones: Las ITU generan altos costos dedicados al manejo inicial y complicaciones. Los nuevos métodos diagnósticos serán de vital importancia en su manejo, pues podrán ofrecer terapias dirigidas al patógeno de manera más oportuna y evitar la resistencia antimicrobiana que sigue representado uno de los grandes conflictos en la actualidad. Los nuevos fármacos pueden ofrecer un manejo más certero en casos de múltiples resistencias antimicrobianas.

Australian Group on Antimicrobial Resistance (AGAR) Australian Staphylococcus aureus Sepsis Outcome Programme (ASSOP) Annual Report 2018.

From 1 January to 31 December 2018, thirty-six institutions around Australia participated in the Australian Staphylococcus aureus Sepsis Outcome Programme (ASSOP). The aim of ASSOP 2018 was to determine the proportion of Staphylococcus aureus bacteraemia (SAB) isolates in Australia that are antimicrobial resistant, with particular emphasis on susceptibility to methicillin, and to characterise the molecular epidemiology of the methicillin-resistant isolates. A total of 2,673 S. aureus bacteraemia episodes were reported, of which 78.9% were community-onset. A total of 17.4% of S. aureus isolates were methicillin resistant. The 30-day all-cause mortality associated with methicillin-resistant SAB was 17.1% which was not significantly higher than the 13.6% mortality associated with methicillin-susceptible SAB (p = 0.1). With the exception of the β-lactams and erythromycin, antimicrobial resistance in methicillin-susceptible S. aureus was rare. However in addition to the β-lactams approximately 42% of methicillin-resistant S. aureus (MRSA) were resistant to erythromycin, 36% to ciprofloxacin and approximately 13% resistant to co-trimoxazole, tetracycline and gentamicin. When applying the EUCAST breakpoints teicoplanin resistance was detected in two S. aureus isolates. Resistance was not detected for vancomycin and linezolid. Resistance to non-beta-lactam antimicrobials was largely attributable to two healthcare-associated MRSA clones: ST22-IV [2B] (EMRSA-15) and ST239-III [3A] (Aus-2/3 EMRSA). The ST22-IV [2B] (EMRSA-15) clone is the predominant healthcare-associated clone in Australia. Seventy-eight percent of methicillin-resistant SAB episodes in 2018 were due to community-associated clones. Although polyclonal, approximately 76.3% of community-associated clones were characterised as ST93-IV [2B] (Queensland CA-MRSA), ST5-IV [2B], ST45-VT [5C2&5], ST1-IV [2B], ST30-IV [2B], ST78-IV [2B] and ST97-IV [2B]. Community-associated MRSA, in particular the ST45-VT [5C2&5] clone, has acquired multiple antimicrobial resistance determinants including ciprofloxacin, erythromycin, clindamycin, gentamicin and tetracycline. The ST45-VT [5C2&5] clone accounted for 11.7% of CA-MRSA. As CA-MRSA is well established in the Australian community, it is important that antimicrobial resistance patterns in community- and healthcare-associated SAB are monitored, as this information will guide therapeutic practices in treating S. aureus sepsis.

Prevalence and trend analysis of antimicrobial resistance in clinical Escherichia coli isolates collected from diseased pigs in the USA between 2006 and 2016.

Antimicrobial resistance (AMR) is an emerging threat to both human and animal health. Antimicrobial use and resistance in food animal production, including swine, has received increased scrutiny as a source of resistant foodborne pathogens. Continuous surveillance of AMR in bacterial isolates of swine origin can guide in conservation of antimicrobials used in both human and swine medicine. The objective of this study was to evaluate the prevalence and trends of the phenotypic AMR in Escherichia coli of swine origin isolated from clinical samples at the Minnesota Veterinary Diagnostic laboratory between 2006 and 2016. The prevalence of resistance to ampicillin, tetracyclines and sulphadimethoxine remained greater than 50% throughout the period. There was a drastic change in enrofloxacin resistance, increasing from less than 1% to more than 20% between 2006 and 2016 (annual relative increase of 57% between 2006 and 2013 and 16% between 2013 and 2016). The prevalence of resistance to other antimicrobials remained constant (ceftiofur, oxytetracycline and chlortetracycline) or changed significantly (annual relative changes of less than 10%) for at least some time-period between 2006 and 2016 (ampicillin, florfenicol, gentamicin, neomycin, sulphadimethoxine, trimethoprim-sulphamethoxazole and spectinomycin). Rarefaction analysis revealed an increase in the number of unique combinations of AMRs per year. Network analysis was performed by estimating and plotting partial correlations between minimum inhibitory concentrations (MICs) of various antimicrobials. An increase in strength of these networks was observed, particularly in networks created after 2010, which can be indicative of increased multiple AMR in these isolates. These results provide valuable insight into the trends in AMR in E. coli of swine origin in the USA and act as supplementary information to the existing active AMR surveillance systems.

A New High-throughput Real-time PCR Assay for the Screening of Multiple Antimicrobial Resistance Genes in Broiler Fecal Samples from China

ObjectiveAntimicrobial resistance (AMR) has become a global concern and is especially severe in China. To effectively and reliably provide AMR data, we developed a new high-throughput real-time PCR assay based on microfluidic dynamic technology, and screened multiple AMR genes in broiler fecal samples. MethodsA high-throughput real-time PCR system with an new designed integrated fluidic circuit assay were performed AMR gene detection. A total of 273 broiler fecal samples collected from two geographically separated farms were screened AMR genes. ResultsThe new assay with limits of detection ranging from 40.9 to 8,000 copies/reaction. The sensitivity rate, specificity rate, positive predictive value, negative predictive value and correct indices were 99.30%, 98.08%, 95.31%, 99.79%, and 0.9755, respectively. Utilizing this assay, we demonstrate that AMR genes are widely spread, with positive detection rates ranging from 0 to 97.07% in 273 broiler fecal samples. blaCTX-M, blaTEM, mcr-1, fexA, cfr, optr A, and intl1 showed over 80% prevalence. The dissemination of AMR genes was distinct between the two farms. ConclusionsWe successfully established a new high-throughput real-time PCR assay applicable to AMR gene surveillance from fecal samples. The widespread existence of AMR genes detected in broiler farms highlights the current and severe problem of AMR.