Genotypic Antibiotic Resistance Research Articles

Clinical evaluation of the acuitas® AMR gene panel for rapid detection of bacteria and genotypic antibiotic resistance determinants

Urinary tract infections are leading causes of hospital admissions. Accurate and timely diagnosis is important due to increasing morbidity and mortality from antimicrobial resistance. We evaluated a polymerase chain reaction test (Acuitas AMR Gene Panel with the Acuitas Lighthouse Software) for detection of 5 common uropathogens (Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Enterococcus faecalis) and antibiotic resistance genes directly from urine for prediction of phenotypic resistance. Overall percent agreement was 97% for semiquantitative detection of uropathogens versus urine culture using a cut-off of 104 colony forming units per mL urine. Overall accuracy was 91% to 93% for genotypic prediction of common antibiotic resistance harbored by E. coli, K. pneumoniae, and P. mirabilis.

Molecular Detection of Antibiotic Resistance Genes in Shiga Toxin-Producing E. coli Isolated from Different Sources.

Shiga toxin-producing Escherichia coli (STEC) is an enteric pathogen associated with human gastroenteritis outbreaks. Extensive use of antibiotics in agriculture selects resistant bacteria that may enter the food chain and potentially causes foodborne illnesses in humans that are less likely to respond to treatment with conventional antibiotics. Due to the importance of antibiotic resistance, this study aimed to investigate the combination of phenotypic and genotypic antibiotic resistance in STEC isolates belonging to serogroups O26, O45, O103, O104, O111, O121, O145, and O157 using disc diffusion and polymerase chain reaction (PCR), respectively. All strains were phenotypically resistant to at least one antibiotic, with 100% resistance to erythromycin, followed by gentamicin (98%), streptomycin (82%), kanamycin (76%), and ampicillin (72%). The distribution of antibiotic resistance genes (ARGs) in the STEC strains was ampC (47%), aadA1 (70%), ere(A) (88%), blaSHV (19%), blaCMY (27%), aac(3)-I (90%), and tet(A) (35%), respectively. The results suggest that most of the strains were multidrug-resistant (MDR) and the most often observed resistant pattern was of aadA1, ere(A), and aac(3)-I genes. These findings indicate the significance of monitoring the prevalence of MDR in both animals and humans around the globe. Hence, with a better understanding of antibiotic genotypes and phenotypes among the diverse STEC strains obtained, this study could guide the administration of antimicrobial drugs in STEC infections when necessary.

Genomic and Phenotypic Analysis of Multidrug-Resistant Acinetobacter baumannii Clinical Isolates Carrying Different Types of CRISPR/Cas Systems.

Acinetobacter baumannii is an opportunistic pathogen being one of the most important causative agents of a wide range of nosocomial infections associated with multidrug resistance and high mortality rate. This study presents a multiparametric and correlation analyses of clinical multidrug-resistant A. baumannii isolates using short- and long-read whole-genome sequencing, which allowed us to reveal specific characteristics of the isolates with different CRISPR/Cas systems. We also compared antibiotic resistance and virulence gene acquisition for the groups of the isolates having functional CRISPR/Cas systems, just CRISPR arrays without cas genes, and without detectable CRISPR spacers. The data include three schemes of molecular typing, phenotypic and genotypic antibiotic resistance determination, as well as phylogenetic analysis of full-length cas gene sequences, predicted prophage sequences and CRISPR array type determination. For the first time the differences between the isolates carrying Type I-F1 and Type I-F2 CRISPR/Cas systems were investigated. A. baumannii isolates with Type I-F1 system were shown to have smaller number of reliably detected CRISPR arrays, and thus they could more easily adapt to environmental conditions through acquisition of antibiotic resistance genes, while Type I-F2 A. baumannii might have stronger “immunity” and use CRISPR/Cas system to block the dissemination of these genes. In addition, virulence factors abaI, abaR, bap and bauA were overrepresented in A. baumannii isolates lacking CRISPR/Cas system. This indicates the role of CRISPR/Cas in fighting against phage infections and preventing horizontal gene transfer. We believe that the data presented will contribute to further investigations in the field of antimicrobial resistance and CRISPR/Cas studies.

Phenotypic and Genotypic Antibiotic Resistance Patterns in Helicobacter pylori Strains From Ethnically Diverse Population in México.

Helicobacter pylori strains carry a range of mutations in genes that confer antimicrobial resistance and restrict the available options to treat the infection. Latin America is a region that conserve a large number of indigenous communities relatively isolated that practice a traditional medicine without consumption of drugs. We hypothesized that rates of antibiotic resistance are lower in these communities. Recent progress in whole-genome sequencing has allowed the study of drug susceptibility by searching for the known mutations associated with antibiotic resistance. The aim of this work was to study trends of antibiotic resistance over a 20-year period in Mexican H. pylori strains and to compare susceptibility between strains from Mexican mestizos and from indigenous population; we also aimed to learn the prevalence of mutational patterns in genes gyrA, gyrB, rdxA, frxA, rpsU, omp11, dppA, and 23S rRNA and its association with phenotypic tests. Resistance to clarithromycin, metronidazole, amoxicillin and levofloxacin was determined in167 H. pylori isolates by E-test, and the occurrence of mutational patterns in specific genes was determined by whole genome sequencing (WGS). The trend of resistance over 20 years in mestizo isolates showed significant resistant increase for clarithromycin and levofloxacin to frequencies that banned its clinical use. Resistance in H. pylori isolates of native communities was lower for all antibiotics tested. Phenotypic resistance showed good to moderate correlation with genotypic tests. Genetic methods for characterizing antibiotic resistance require further validation in each population.

Antimicrobial resistance of Staphylococcus spp. isolated from organic and conventional Minas Frescal cheese producers in São Paulo, Brazil

The genus Staphylococcus is recognized worldwide as a cause of bacterial infections in humans and animals. Antibiotics used in dairy cattle combined with ineffective control can increase antimicrobial resistance. The objective of this study was to characterize 95 Staphylococcus strains isolated from organic and conventional Minas Frescal cheese production regarding antibiotic resistance (phenotype and genotype), presence of sanitizer-resistant genes and biofilm-formation genes, and SCCmec typing. Most strains (25.3%) showed higher resistance to penicillin, followed by oxacillin (21.1%) and clindamycin (11.6%). Among antibiotic resistance genes, the most prevalent were blaZ (25.3%), mecA (13.7%), lsaB (6.3%), msrA (4.2%), ant4 (3.2%), and tetM (2.1%); among sanitizer-resistance genes they were qacA/B (5.3%) and qacC (6.3%); and among biofilm, bap (4.2%), icaA (29.5%), icaD (41.1%). However, there was no statistically significant difference between organic and conventional dairy products, possibly due to the lack of synthetic antibiotic use on conventional farms during the sample collection period. Methicillin-resistant Staphylococcus aureus (MRSA) had their SCCmec identified as types I and IVc, and the methicillin-resistant coagulase-negative staphylococci had nontypeable SCCmec. These results suggest that there are antibiotic-resistant strains in both organic and conventional Minas Frescal cheese production in the state of São Paulo, Brazil. This supports the idea that improved quality control is needed from the milking stage up to the final product.

Homology analysis between clinically isolated extraintestinal and enteral Klebsiella pneumoniae among neonates

BackgroundKlebsiella pneumoniae is a leading cause of hospital-associated (HA) infections. It has been reported that gastrointestinal colonization (GI) is likely to be a common and significant reservoir for the transmission and infections of K. pneumoniae in both adults and neonates. However, the homologous relationship between clinically isolated extraintestinal and enteral K. pneumoniae in neonates hasn’t been characterized yet.ResultsForty-three isolates from 21 neonatal patients were collected in this study. The proportion of carbapenem resistance was 62.8%. There were 12 patients (12/21, 57.4%) whose antibiotic resistance phenotypes, genotypes, and ST types (STs) were concordant. Six sequence types were detected using MLST, with ST37 and ST54 being the dominant types. The results of MLST were consist with the results of PFGE.ConclusionsThese data showed that there might be a close homologous relationship between extraintestinal K. pneumoniae (EXKP) and enteral K. pneumoniae (EKP) in neonates, indicating that the K. pneumoniae from the GI tract is possibly to be a significant reservoir for causing extraintestinal infections.

Phenotypic and genotypic antibiotic resistance in bacteria of family Enterobacteriaceae, obtained from agricultural enterprises of the Ural region

Phenotypic and genotypic antibiotic resistance in bacteria of family Enterobacteriaceae, obtained from agricultural enterprises of the Ural region

Distribution of Genotypic and Phenotypic Antibiotic Resistance in a Conventional Watewater Treatment Plant (Wwtp) in Two Years

Distribution of Genotypic and Phenotypic Antibiotic Resistance in a Conventional Watewater Treatment Plant (Wwtp) in Two Years

Prevalence of <i>Escherichia coli</i> and Antibiotic Resistance in Animal-Derived Food Samples — Six Districts, Beijing, China, 2020

What is already known about this topic?Escherichia coli is an important hygiene indicator for animal-derived foods such as pork and chicken, and the contamination of retail meat is associated with the spread of antimicrobial resistance (AMR) and public health. What is added by this report?The prevalence of E. coli in 6 different districts of Beijing was 64.1%. The contamination of chicken was more serious than pork in Beijing. E. coli isolates were highly resistant to sulfonamides (87.4%). TheampC1 and ampC2 genes were the main antibiotic resistance genotype (94.7% and 99.4%). What are the implications for public health practice?This study highlights the need to strengthen the surveillance of antibiotic resistance of E. coli in animal-derived foods. A national or regional multicenter study is required to assess the dissemination and evolution of multidrug resistant (MDR) E. coli in clinical medicine and animal production for food.

Biofilm formation in uropathogenic Escherichia coli strains; Relationship with virulence factors and antimicrobial resistance

Background: Urinary tract infection (UTI) is a clinical condition with characteristic symptoms, colonization and multiplication of bacteria in significant numbers. At this juncture, antimicrobial resistance in uropathogens has become one of the major concerns globally. Therefore, the present study aimed to demonstrate the biofilm formation in uropathogenic Escherichia coli strains; characterize the phenotypic & genotypic virulence factors and their relationship with antimicrobial resistance. Methods and materials: In this study, 1000 suspected UTI cases were included. Urine samples were processed for culture and antimicrobial drug susceptibility testing. Only Escherichia coli isolates were further studied for production of biofilm, ESBL and haemolysin enzymes by phenotypic methods. Virulence genes, papEF, traT & PAI were detected by multiplex PCR. Molecular confirmation & characterization of virulence genes was done by Sanger sequencing. Results: From the 1000 urine samples, 395 E. coli were isolated. Higher resistance was observed with antibiotics - ampicillin (82.53%), cefuroxime (72.41%), amoxicillin-clavulanic acid (71.90%), ceftriaxone (66.58%), ciprofloxacin (65.82%) and cefepime (57.47%). In-vitro biofilm was formed by 71.39% isolates. Biofilm-forming strains developed higher resistance towards ampicillin, cefuroxime, amoxicillin-clavulanic acid, ciprofloxacin, cefepime and ceftriaxone. Phenotypic methods detected 62.3% isolates as ESBL producers and 40.2% were β-haemolytic. Virulence gene characterization revealed presence of traT in 73.2% strains, PAI & papEF among 62.9% and 33.5% strains. ESBL & Hemolysin producing UPEC exhibited higher resistant to ampicillin, amoxicillin-clavulanic acid, aztreonam, cefriaxone, cefuroxime, cefepime, ciprofloxacin, chloramphenicol & gentamicin. Statistically proved association was seen with gene RPAI and traT with antibiotics nitrofurantoin and amikacin. All the isolates were sensitive to nitrofurantoin, piperacillin-tazobactam, and imipenem. Strains showed 99% sequence identity and no mutations were detected. Conclusion: Increase in trend of resistance was observed with antibiotics which were routinely used to treat UTI. Results indicated significant correlation between phenotypic and genotypic virulence factors and antibiotic resistance. Antibiotics nitrofurantoin, piperacillin - tazobactam, and imipenem can be effective for severe UTIs. This study concludes that expression of virulence factors by UPEC strains is responsible for increased antibiotic resistance. Hence, characterizing the UPEC strains help clinicians to reach a better therapeutic outcomes and treatment regimens in this region.

Antibiotic Susceptibility and Molecular Characterization of Uropathogenic Escherichia coli Associated with Community-Acquired Urinary Tract Infections in Urban and Rural Settings in South Africa.

We investigated the phenotypic and genotypic antibiotic resistance, and clonality of uropathogenic Escherichia coli (UPEC) implicated in community-acquired urinary tract infections (CA-UTIs) in KwaZulu-Natal, South Africa. Mid-stream urine samples (n = 143) were cultured on selective media. Isolates were identified using the API 20E kit and their susceptibility to 17 antibiotics tested using the disk diffusion method. Extended-spectrum β-lactamases (ESBLs) were detected using ROSCO kits. Polymerase chain reaction (PCR) was used to detect uropathogenic E. coli (targeting the papC gene), and β-lactam (blaTEM/blaSHV-like and blaCTX-M) and fluoroquinolone (qnrA, qnrB, qnrS, gyrA, parC, aac(6’)-Ib-cr, and qepA) resistance genes. Clonality was ascertained using ERIC-PCR. The prevalence of UTIs of Gram-negative etiology among adults 18–60 years of age in the uMgungundlovu District was 19.6%. Twenty-six E. coli isolates were obtained from 28 positive UTI samples. All E. coli isolates were papC-positive. The highest resistance was to ampicillin (76.9%) and the lowest (7.7%) to amoxicillin/clavulanic acid and gentamycin. Four isolates were multidrug-resistant and three were ESBL-positive, all being CTX-M-positive but SHV-negative. The aac(6’)-Ib-cr and gyrA were the most detected fluoroquinolone resistance genes (75%). Isolates were clonally distinct, suggesting the spread of genetically diverse UPEC clones within the three communities. This study highlights the spread of genetically diverse antibiotic-resistant CA-UTI aetiologic agents, including multidrug-resistant ones, and suggests a revision of current treatment options for CA-UTIs in rural and urban settings.

The changing epidemiology of carbapenemase-producing Klebsiella pneumoniae in Italy: toward polyclonal evolution with emergence of high-risk lineages.

Previous studies showed that the epidemic of carbapenem-resistant Klebsiella pneumoniae (CR-KP) observed in Italy since 2010 was sustained mostly by strains of clonal group (CG) 258 producing KPC-type carbapenemases. In the framework of the National Antibiotic-Resistance Surveillance (AR-ISS), a countrywide survey was conducted in 2016 to explore the evolution of the phenotypic and genotypic characteristics of CR-KP isolates. From March to July 2016, hospital laboratories participating in AR-ISS were requested to provide consecutive, non-duplicated CR-KP (meropenem and/or imipenem MIC >1 mg/L) from invasive infections. Antibiotic susceptibility was determined according to EUCAST recommendations. A WGS approach was adopted to characterize the isolates by investigating phylogeny, resistome and virulome. Twenty-four laboratories provided 157 CR-KP isolates, of which 156 were confirmed as K. pneumoniae sensu stricto by WGS and found to carry at least one carbapenemase-encoding gene, corresponding in most cases (96.1%) to blaKPC. MLST- and SNP-based phylogeny revealed that 87.8% of the isolates clustered in four major lineages: CG258 (47.4%), with ST512 as the most common clone, CG307 (19.9%), ST101 (15.4%) and ST395 (5.1%). A close association was identified between lineages and antibiotic resistance phenotypes and genotypes, virulence traits and capsular types. Colistin resistance, mainly associated with mgrB mutations, was common in all major lineages except ST395. This WGS-based survey showed that, although CG258 remained the most common CR-KP lineage in Italy, a polyclonal population has emerged with the spread of the new high-risk lineages CG307, ST101 and ST395, while KPC remained the most common carbapenemase.

Prevalence, Genotypic and Phenotypic Characterization and Antibiotic Resistance Profile of Clostridium perfringens Type A and D Isolated from Feces of Sheep (Ovis aries) and Goats (Capra hircus) in Punjab, Pakistan.

Clostridium perfringens poses a serious threat to small ruminants by causing moderate to severe enterotoxaemia. Due to its ability to produce a wide arsenal of toxins, it is ranked among the most prevalent and important pathogens in livestock. This study focused on the molecular characterization of different Clostridium perfringens types along with their antimicrobial resistance profile. An overall higher prevalence of C. perfringens (46.1%) was detected based on mPCR among sheep and goats (healthy and diseased) in the Punjab province, Pakistan. The majority of the isolates were characterized as type A (82%), followed by type D (18%). Among the isolates from diseased sheep and goats, 27% were positive for cpa, 49% for cpa and cpb2, 9% for cpa and etx, 15% for cpa, cpb2 and etx. In the case of isolates from healthy sheep and goats, 59% were positive for cpa, 34% for cpb2 and cpa, 4% for cpa and etx, and 3% for cpa, cpb2 and etx. The prevalence of the beta2 toxin gene in the diseased sheep and goat population was 64% as compared to 37% in healthy animals. All 184 isolates (100%) were sensitive to rifampin and ceftiofur; the majority (57%) was sensitive to teicoplanin, chloramphenicol, amoxicillin, linezolid and enrofloxacin. A lower proportion of isolates (43%) were sensitive to ciprofloxacin and only 14% were susceptible to erythromycin. The findings of this study highlight the higher prevalence of C. perfringens in small ruminants and indicate that detailed pathogenesis studies are necessary to understand the explicit role of various toxins in causing enteric infections in sheep and goats including how they might be exploited to develop vaccines against these diseases.

Molecular identification and antibiotic resistance of bacteriocinogenic lactic acid bacteria isolated from table olives.

In the present study, lactic acid bacteria were isolated from table olive in Morocco. Random Amplified Polymorphic DNA fingerprinting with (GTG)'(5) primer revealed a remarquable variability within isolates. According to the molecular identification, Enterococcus faecium was the most dominant species isolated with 32 strains (84.21%), followed by 4 strains of Weissella paramesenteroides (10.52%), 1 strain of Leuconostoc mesenteroides (2.63%) and Lactobacillus plantarum (2.63%). All of the strains that were identified showed occurrence of more than one bacteriocin-encoding gene. Based on the results obtained, L. plantarum 11 showed a mosaic of loci coding for nine bacteriocins (pln A, pln D, pln K, pln G, pln B, pln C, pln N, pln J, ent P). A phenotypic and genotypic antibiotic resistance was also examined. L. plantarum 11, L. mesenteroides 62, W. paramesenteroides 9 and W. paramesenteroides 36 as well as all the strains of E. faecium were susceptible to ampicillin, clindamycin and teicoplanin; however, isolates showed a resistance profile against tetracycline and erythromycin. Except E. faecium 114, E. faecium 130 and L. plantarum 11, no antibiotic resistance genes were detected in all of the strains, which might be due to resistances resulting from non-transferable or non-acquired resistance determinants (intrinsic mechanism).

Methicillin resistant Staphylococcus aureus (MRSA) from community associated settings

Antibiotic resistance is a cause of concern worldwide. Community settings are important reservoir of drug resistant microorganisms like Staphylococcus aureus. The present study was to determine the prevalence, phenotypic and genotypic antibiotic resistance pattern of S. aureus isolated from different community settings of university campus. A total of 300 swab samples were collected for isolation of S. aureus from different community settings at university campus of Guru Angad Dev Veterinary and Animal Sciences University and Punjab Agriculture University, Ludhiana, India. Confirmed S. aureus isolates were further subjected to antibiotic sensitivity by Epsilometer test (E-test) and detection of antibiotic resistance genes. The prevalence of S. aureus in the community samples was 12% (36/300). Methicillin Resistant S. aureus (MRSA) contamination among community was 3.33% (10/300). Among S. aureus isolates from community samples 63.8% (23/36) and all the MRSA isolates were multidrug resistant (MDR). Five out of 10 MRSA carried SCCmec type IVa, and 4 were pvl positive gene, therefore, designated as community associated MRSA (CA-MRSA). Phenotypic resistance to antibiotics ciprofloxacin, chloramphenicol, ceftriaxone clindamycin and trimethoprim-sulfamethoxazole was 69.4% (MIC ≥32 μg/ml), 63.9% (MIC 32 μg/ ml), 16.7% (MIC 16–64 μg/ml), 16.7% (MIC 256 μg/ml) and 8.3% (MIC 12–64 μg/ml), respectively. Resistance genes blaZ, mecA, tetK, tetM, ermB and aacA-aphD were present. Presence of MRSA and MDR variant in community settings is a public health concern, as cell phone, offices telephone, computer keyboard and tap faucet are commonly shared or touched by people. Therefore, have potential to disseminate widely, not only in the community settings but also in hospitals environment, complicating treatment.

Staphylococci among Wild European Rabbits from the Azores: A Potential Zoonotic Issue?

The prevalence and diversity of Staphylococcus species from wild European rabbits (Oryctolagus cuniculus) in the Azores were investigated, and the antibiotic resistance phenotype and genotype of the isolates were determined. Nasal samples from 77 wild European rabbits from São Jorge and São Miguel islands in Azores were examined. Antibiotic susceptibility of the isolates was determined using the Kirby-Bauer disk diffusion method, and the presence of antimicrobial resistance genes and virulence factors was determined by PCR. The genetic lineages of S. aureus isolates were characterized by spa typing and multilocus sequence typing. A total of 49 staphylococci were obtained from 35 of the 77 wild rabbits. Both coagulase-positive (8.2%) and coagulase-negative (91.8%) staphylococci were detected: 4 S. aureus, 17 S. fleurettii, 13 S. sciuri, 7 S. xylosus, 4 S. epidermidis, and 1 each of S. simulans, S. saprophyticus, S. succinus, and S. equorum. The four S. aureus isolates showed methicillin susceptibility and were characterized as spa type t272/CC121, Panton-Valentine leukocidin negative, and hlB positive. Most of the coagulase-negative staphylococci showed resistance to fusidic acid and beta-lactams, and multidrug resistance was identified especially among S. epidermidis isolates. The mecA gene was detected in 20 isolates of the species S. fleurettii and S. epidermidis, associated with the blaZ gene in one S. epidermidis isolate. Five antimicrobial resistance genes were detected in one S. epidermidis isolate (mecA,dfrA,dfrG,aac6'-aph2'', and ant4). Our results highlight that wild rabbits are reservoirs or "temporary hosts" of Staphylococcus species with zoonotic potential, some of them carrying relevant antimicrobial resistances.

Genotypic and Phenotypic Diversity of Staphylococcus aureus Isolates from Cystic Fibrosis Patient Lung Infections and Their Interactions with Pseudomonas aeruginosa.

Staphylococcus aureus has recently overtaken Pseudomonas aeruginosa as the most commonly recognized bacterial pathogen that infects the respiratory tracts of individuals with the genetic disease cystic fibrosis (CF) in the United States. Most studies of S. aureus in CF patient lung infections have focused on a few isolates, often exclusively laboratory-adapted strains, and how they are killed by P. aeruginosa Less is known about the diversity of S. aureus CF patient lung isolates in terms of both their virulence and their interaction with P. aeruginosa To begin to address this gap, we recently sequenced 64 clinical S. aureus isolates and a reference isolate, JE2. Here, we analyzed the antibiotic resistance genotypes, sequence types, clonal complexes, spa types, agr types, and presence/absence of other known virulence factor genes of these isolates. We hypothesized that virulence phenotypes of S. aureus, namely, toxin production and the mucoid phenotype, would be lost in these isolates due to adaptation in the CF patient lung. In contrast to these expectations, we found that most isolates can lyse both rabbit and sheep blood (67.7%) and produce polysaccharide (69.2%), suggesting that these phenotypes were not lost during adaptation to the CF lung. We also identified three distinct phenotypic groups of S. aureus based on their survival in the presence of nonmucoid P. aeruginosa laboratory strain PAO1 and its mucoid derivative. Altogether, our work provides greater insight into the diversity of S. aureus isolates from CF patients, specifically the distribution of important virulence factors and their interaction with P. aeruginosa, all of which have implications in patient health.IMPORTANCEStaphylococcus aureus is now the most frequently detected recognized pathogen in the lungs of individuals who have cystic fibrosis (CF) in the United States, followed closely by Pseudomonas aeruginosa When these pathogens are found to coinfect the CF lung, patients have a significantly worse prognosis. While P. aeruginosa has been rigorously studied in the context of bacterial pathogenesis in CF, less is known about S. aureus Here, we present an in-depth study of 64 S. aureus clinical isolates from CF patients, for which we investigated genetic diversity utilizing whole-genome sequencing, virulence phenotypes, and interactions with P. aeruginosa We found that S. aureus isolated from CF lungs are phylogenetically diverse; most retain known virulence factors and vary in their interactions with P. aeruginosa (i.e., they range from being highly sensitive to P. aeruginosa to completely tolerant to it). Deepening our understanding of how S. aureus responds to its environment and other microbes in the CF lung will enable future development of effective treatments and preventative measures against these formidable infections.

Virulence gene transcription, phylogroups, and antibiotic resistance of cervico-vaginal pathogenic E. coli in Mexico.

The pathogenicity of Escherichia coli strains that cause cervico-vaginal infections (CVI) is due to the presence of several virulence genes. The objective of this study was to define the variability regarding the genotype of antibiotic resistance, the transcription profiles of virulence genes after in vitro infection of the vaginal cell line A431 and the phylogroup composition of a group of cervico-vaginal E. coli strains (CVEC). A total of 200 E. coli strains isolated from Mexican women with CVI from two medical units of the Mexican Institute of Social Security were analysed. E. coli strains and antibiotic resistance genes were identified using conventional polymerase chain reaction (PCR), and phylogroups were identified using multiplex PCR. Virulence gene transcription was measured through reverse-transcriptase real-time PCR after infection of the vaginal cell line A431. The most common antibiotic resistance genes among the CVEC strains were aac(3)II, TEM, dfrA1, sul1, and qnrA. The predominant phylogroup was B2. The genes most frequently transcribed in these strains were fimH, papC, irp2, iroN, kpsMTII, cnf1, and ompT, mainly in CVEC strains isolated from chronic and occasional vaginal infections. The strains showed a large diversity of transcription of the virulence genes phenotype and antibiotic resistance genotype, especially in the strains of phylogroups, B2, A, and D. The strains formed 2 large clusters, which contained several subclusters. The genetic diversity of CVEC strains was high. These strains have a large number of transcription patterns of virulence genes, and one-third of them carry three to seven antibiotic resistance genes.

Molecular Typing, Characterization of Antimicrobial Resistance, Virulence Profiling and Analysis of Whole-Genome Sequence of Clinical Klebsiella pneumoniae Isolates.

Klebsiella pneumoniae is one of the most important pathogens concerned with multidrug resistance in healthcare-associated infections. The treating of infections caused by this bacterium is complicated due to the emergence and rapid spreading of carbapenem-resistant strains, which are associated with high mortality rates. Recently, several hypervirulent and carbapenemase-producing isolates were reported that make the situation even more complicated. In order to better understand the resistance and virulence mechanisms, and, in turn, to develop effective treatment strategies for the infections caused by multidrug-resistant K. pneumoniae, more comprehensive genomic and phenotypic data are required. Here, we present the first detailed molecular epidemiology report based on second and third generation (long-read) sequencing for the clinical isolates of K. pneumoniae in the Russian Federation. The data include three schemes of molecular typing, phenotypic and genotypic antibiotic resistance determination, as well as the virulence and plasmid profiling for 36 K. pneumoniae isolates. We have revealed 2 new multilocus sequence typing (MLST)-based sequence types, 32 multidrug-resistant (MDR) isolates and 5 colistin-resistant isolates in our samples. Three MDR isolates belonged to a very rare ST377 type. The whole genome sequences and additional data obtained will greatly facilitate further investigations in the field of antimicrobial resistance studies.

Genotypic and Phenotypic Antibiotic Resistance in Staphylococcus Epidermidis Endophthalmitis.

To evaluate antibiotic resistance patterns in Staphylococcus epidermis endophthalmitis isolates, identify antibiotic resistance genes, and compare this to their phenotypic resistance. Retrospective case series of S. epidermidis isolates from January 2012 to December 2017. Phenotypic resistance was determined from minimum inhibitory concentration values. Genotypic resistance was determined from DNA microarray. The relationship between these was analyzed using Cohen's kappa and predictive value. Seventy-five isolates were included. More than 60% were resistant to methicillin and erythromycin. Approximately 60% possessed the resistance genes for methicillin and erythromycin, and 25% for clindamycin. There was near perfect agreement between genotype and phenotype for erythromycin and methicillin (kappa = 0.88 and 0.89, respectively). Approximately 98% (P < 0.0001) of isolates with erythromycin and methicillin resistance genes and 90% (P = 0.0006) with clindamycin resistance genes were phenotypically resistant to those antibiotics. None were resistant to vancomycin. The relationship between genotypic and phenotypic antibiotic resistance highlights that resistance may be polygenic, and genes may be silent. [Ophthalmic Surg Lasers Imaging Retina. 2020;51:S13-S16.].