SPM-1-producing Pseudomonas aeruginosa ST277 clone recovered from microbiota of migratory birds

Regulation, structure, and activity of the Pseudomonas aeruginosa MexXY efflux system

The current crisis in bacterial antibiotic resistance can be attributed to the overuse (or misuse) of these essential medicines in healthcare and agriculture, coupled with the slowed progression of new drug development. In the versatile, opportunistic pathogen Pseudomonas aeruginosa, the Resistance-Nodulation-Division (RND) efflux pump MexXY plays critical roles in both cell physiology and the acquisition of multidrug resistance. The mexXY operon is not constitutively expressed, but this process is instead controlled by a complex network of multiple interconnected regulatory mechanisms. These include induction by several of the pump's ribosome-targeting antibiotic substrates and transcriptional repression and anti-repression processes that are themselves influenced by various cellular factors, processes, or stresses. Although extensive studies of the MexXY complex are currently lacking as compared to other RND efflux pumps such as Escherichia coli AcrAB-TolC, recent studies have provided valuable insights into the MexXY architecture and substrate profiles, including its contribution to clinical resistance. Furthermore, while MexXY primarily associates with the outer membrane protein OprM, emerging evidence suggests that this transporter-periplasmic adaptor pair may also partner with other outer membrane proteins, potentially to alter the efflux substrate profile and activity under specific environmental conditions. In this minireview, we summarize current understanding of MexXY regulation, structure, and substrate selectivity within the context of clinical resistance and as a framework for future efflux pump inhibitor development.

Global epidemiology of high priority and pandemic Pseudomonas aeruginosa in pets, livestock, wild, and aquatic animals: a systematic review and meta-analysis

High-priority and international high-risk Pseudomonas aeruginosa (PA) are emergent strains. Here, we performed the first systematic review and meta-analysis of studies that reported the frequency of PA, carbapenem (CARBR), and colistin (COLR) resistant PA in healthy and sick livestock (A), pets (B), wild (C), and aquatic animals (D) from January 2013 to January 2023, globally. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, 57 cross-sectional and eight prospective studies were found eligible. Random-effect models were used to determine the pooled prevalences. Phylogenetic analyses based on core-genome single nucleotide polymorphisms (SNPs) were performed using CSI Phylogeny 1.4. The overall pooled prevalence of PA, COLR-PA, and CARBR-PA were 18.6%, 4%, and 11.7%, respectively. Wild animals had the highest pooled prevalence of PA, 33.5%. The pooled prevalence of COLR was significantly higher in PA strains from sick than healthy animals (P < 0.0001). Furthermore, COLR was significantly highest in PA strains from wild animals, 9.8% [95% confidence interval (CI): 0.8-58.9], while CARBR was highest in PA strains from pets, 14.8% (95% CI: 6.7-29.8). Seven (ST235, ST111, ST233, ST244, ST357, ST308, and ST277) of the 10 high-risk CARBR-PA clones carrying ExoS/U were reported in animals. The SNP-based phylogenetic analysis of 23 genomes of CARBR-PA from animals obtained from publicly available databases revealed two closely related blaGES-carrying strains (<100 SNPs) in sick pets, suggesting a transmission event. A higher frequency of high-risk carbapenem than colistin-resistant PA strains exists in animals. These findings highlight the roles of different animal species, especially pets and wild animals in the persistence and dissemination of high-priority PA.

Impact of Antimicrobial Resistance of Pseudomonas aeruginosa in Urine of Small Companion Animals in Global Context: Comprehensive Analysis

The isolation of multidrug-resistant (MDR) bacteria from the urinary tracts of pets is increasingly common, particularly in animals with concurrent health conditions. Pseudomonas aeruginosa (PA) is one of the most significant antimicrobial-resistant bacteria affecting cats and dogs within the European Union (EU). This study aims to review the prevalence and antimicrobial resistance patterns of PA isolated from urine samples of small animals globally. This pathogen is known for its opportunistic infections and is a significant concern in veterinary medicine due to its inherent resistance to multiple antibiotics and its ability to acquire additional resistance mechanisms. This review seeks to enhance educational initiatives regarding the management of emerging MDR bacteria.

Detection of virulent Klebsiella pneumoniae strains causing intestinal and extraintestinal infections during the 80s and 90s in Brazil

Klebsiella pneumoniae is an important pathogen that causes several human infections, which is currently among the main bacterial species of clinical importance. Given the importance of understanding the characteristics of this pathogen and its evolutionary aspects, in this study, we sought to characterize strains of K. pneumoniae recovered in the 1980s and 1990s in São Paulo, Brazil. Our analyses included 48 strains recovered from diarrheagenic stools and extraintestinal infections. These strains were submitted to screening for virulence and ESβL-encoding genes, antimicrobial susceptibility tests, biofilm formation, and hypermucosity and hemolytic activity tests. Our results revealed that among the studied virulence genes, the most frequent were entB (100%), followed by iutA (100%), mrkD (98%), and ycfM (72%). Phenotypic tests revealed that the strains were non- hemolytic, and two strains were positive for the hypermucoviscosity phenotype but did not have the genetic markers associated with this phenotype. Furthermore, 17% of the isolates proved to be strong biofilm producers. Antimicrobial susceptibility testing demonstrated that most strains were susceptible to the tested antimicrobials, with the exception of five isolates that produced CTX-M-2. Our findings indicate that the collection of strains studied showed variability in virulence factors, as well as biofilm production. Still, a minority of the strains showed clinically significant resistance mechanisms. As far as we know, this is the oldest collection of K. pneumoniae studied in the country.Keywords: Bacterial virulence; Ancient bacterial strains; Enterobacterales; Bacterial infection; Diarrhea.

Emergence of multidrug-resistant Providencia rettgeri clone in food-producing animals: A public health threat

The occurrence of carbapenemases encoding genes in Providencia rettgeri is a critical public health concern since this species has intrinsic resistance to several antimicrobials, including polymyxins. The identification of this multidrug-resistant (MDR) pathogen outside the hospital setting has become increasingly frequent, and raises an alert for the global health agencies, as they indicate a possible spread of such pathogens. Herein, we described three MDR P. rettgeri isolates carrying a diversity of antimicrobial resistance genes (ARGs) isolated from stool samples of swine and bovine in Brazil. Molecular analysis revealed that all isolates belonged to the same clone. The whole genome sequencing (WGS) of a representative isolate (PVR-188) was performed by MiSeq Illumina® platform, while the assembling and annotation was achieved using SPAdes and Prooka, respectively. The WGS analyses indicated the presence of ARGs that confer resistance to β-lactams (bla NDM-1, bla CTX-M-2), quinolones (qnrD1), aminoglycosides (aadA2, aadA1, aph(3')-Via), phenicol (catB2), sulfonamides (sul1, sul2), and trimethoprim (dfrA12, dfrA1). The presence of three plasmid replicons (Col3M, IncQ1, and IncT) was detected, but no phage sequences were found. The phylogenetic analyses confirmed the genomic relationship of the PVR-188 with P. rettgeri isolates recovered from animals and humans in the USA and Malaysia. In conclusion, we report the occurrence of MDR P. rettgeri clone colonizing the gut microbiota of food-producing animals in Brazil, revealing the spread of this pathogen beyond hospital boundaries.

Molecular Epidemiology of Pseudomonas aeruginosa in Brazil: A Systematic Review and Meta-Analysis

BACKGROUND

Globally, Pseudomonas aeruginosa is a high-priority opportunistic pathogen which displays several intrinsic and acquired antimicrobial resistance (AMR) mechanisms, leading to challenging treatments and mortality of patients. Moreover, its wide virulence arsenal, particularly the type III secretion system (T3SS) exoU+ virulotype, plays a crucial role in pathogenicity and poor outcome of infections. In depth insights into the molecular epidemiology of P. aeruginosa, especially the prevalence of high-risk clones (HRCs), are crucial for the comprehension of virulence and AMR features and their dissemination among distinct strains. This study aims to evaluate the prevalence and distribution of HRCs and non-HRCs among Brazilian isolates of P. aeruginosa.

METHODS

A systematic review and meta-analysis were conducted on studies published between 2011 and 2023, focusing on the prevalence of P. aeruginosa clones determined by multilocus sequence typing (MLST) in Brazil. Data were extracted from retrospective cross-sectional and case-control studies, encompassing clinical and non-clinical samples. The analysis included calculating the prevalence rates of various sequence types (STs) and assessing the regional variability in the distribution of HRCs and non-HRCs.

RESULTS

A total of 872 samples were analyzed within all studies, of which 298 (34.17%) were MLST typed, identifying 78 unique STs. HRCs accounted for 48.90% of the MLST-typed isolates, with ST277 being the most prevalent (100/298-33.55%), followed by ST244 (29/298-9.73%), ST235 (13/298-4.36%), ST111 (2/298-0.67%), and ST357 (2/298-0.67%). Significant regional variability was observed, with the Southeast region showing a high prevalence of ST277, while the North region shows a high prevalence of MLST-typed samples and HRCs.

CONCLUSIONS

Finally, this systematic review and meta-analysis highlight the role of P. aeruginosa clones in critical issue of AMR in P. aeruginosa in Brazil and the need of integration of comprehensive data from individual studies.

Characterization of acquired β-lactamases in Pseudomonas aeruginosa and quantification of their contributions to resistance

Pseudomonas aeruginosa is a highly problematic opportunistic pathogen that causes a range of different infections. Infections are commonly treated with β-lactam antibiotics, including cephalosporins, monobactams, penicillins, and carbapenems, with carbapenems regarded as antibiotics of last resort. Isolates of P. aeruginosa can contain horizontally acquired bla genes encoding β-lactamase enzymes, but the extent to which these contribute to β-lactam resistance in this species has not been systematically quantified. The overall aim of this research was to address this knowledge gap by quantifying the frequency of β-lactamase-encoding genes in P. aeruginosa and by determining the effects of β-lactamases on susceptibility of P. aeruginosa to β-lactams. Genome analysis showed that β-lactamase-encoding genes are present in 3% of P. aeruginosa but are enriched in carbapenem-resistant isolates (35%). To determine the substrate antibiotics, 10 β-lactamases were expressed from an integrative plasmid in the chromosome of P. aeruginosa reference strain PAO1. The β-lactamases reduced susceptibility to a variety of clinically used antibiotics, including carbapenems (meropenem, imipenem), penicillins (ticarcillin, piperacillin), cephalosporins (ceftazidime, cefepime), and a monobactam (aztreonam). Different enzymes acted on different β-lactams. β-lactamases encoded by the genomes of P. aeruginosa clinical isolates had similar effects to the enzymes expressed in strain PAO1. Genome engineering was used to delete β-lactamase-encoding genes from three carbapenem-resistant clinical isolates and increased susceptibility to substrate β-lactams. Our findings demonstrate that acquired β-lactamases play an important role in β-lactam resistance in P. aeruginosa, identifying substrate antibiotics for a range of enzymes and quantifying their contributions to resistance.IMPORTANCEPseudomonas aeruginosa is an extremely problematic pathogen, with isolates that are resistant to the carbapenem class of β-lactam antibiotics being in critical need of new therapies. Genes encoding β-lactamase enzymes that degrade β-lactam antibiotics can be present in P. aeruginosa, including carbapenem-resistant isolates. Here, we show that β-lactamase genes are over-represented in carbapenem-resistant isolates, indicating their key role in resistance. We also show that different β-lactamases alter susceptibility of P. aeruginosa to different β-lactam antibiotics and quantify the effects of selected enzymes on β-lactam susceptibility. This research significantly advances the understanding of the contributions of acquired β-lactamases to antibiotic resistance, including carbapenem resistance, in P. aeruginosa and by implication in other species. It has potential to expedite development of methods that use whole genome sequencing of infecting bacteria to inform antibiotic treatment, allowing more effective use of antibiotics, and facilitate the development of new antibiotics.

Unravelling the genomic characteristics of a Klebsiella quasipneumoniae clinical isolate carrying blaNDM-1

OBJECTIVE

Despite the increasing reports of blaNDM in Enterobacterales in Brazil, comprehensive whole genome sequencing (WGS) data remain scarce. To address this knowledge gap, our study focuses on the characterization of the genome of an New Delhi Metallo-β-lactamase (NDM)-1-producing Klebsiella quasipneumoniae subsp. quasipneumoniae (KQPN) clinical strain isolated in Brazil.

METHODS

The antimicrobial susceptibility profile of the A-73.113 strain was performed by agar dilution or broth microdilution following the Brazilian Antimicrobial Susceptibility Testing Committee/European Committee on Antimicrobial Susceptibility Testing recommendations. WGS was performed using the Illumina® NextSeq platform and the generated reads were assembled using the SPAdes software. The sequences obtained were submitted to the bioinformatics pipelines to determine the sequence type, resistome, plasmidome, and virulome.

RESULTS

The A-73.113 strain was identified as KQPN and was susceptible to polymyxins (MICs, ≤0.25 µg/mL), tigecycline (MIC, 0.5 µg/mL), ciprofloxacin (MIC, 0.5 µg/mL), and levofloxacin (MIC, 1 µg/mL). WGS analysis revealed the presence of genes conferring resistance to β-lactams (blaNDM-1, blaCTX-M-15, blaOXA-9, blaOKP-A-5, blaTEM-1), aminoglycosides [aph(3')-VI, aadA1, aac(6')-Ib], and fluoroquinolones (oqxAB, qnrS1, aac(6')-Ib-cr]. Additionally, the presence of the plasmid replicons Col(pHAD28), IncFIA(HI1), IncFIB(K) (pCAV1099-114), IncFIB(pQil), and IncFII(K), as well as virulence-encoding genes fimABCDEFGHIK (type 1 fimbria), pilW (type IV pili), iutA (aerobactin), entABCDEFS/fepABCDG/fes (Ent siderophores), iroE (salmochelin), and allABCDRS (allantoin utilization) was verified. Furthermore, we found that the A-73.113 strain belongs to ST1040.

CONCLUSIONS

Here we report the genomic characteristics of an NDM-1-producing KQPN ST1040 strain isolated from blood cultures in Brazil. These data will enhance our comprehension of how this species contributes to the acquisition and dissemination of blaNDM-1 in Brazilian nosocomial settings.

Molecular Analysis of Carbapenem and Aminoglycoside Resistance Genes in Carbapenem-Resistant Pseudomonas aeruginosa Clinical Strains: A Challenge for Tertiary Care Hospitals

Carbapenem-resistant Pseudomonas aeruginosa (P. aeruginosa) strains have become a global threat due to their remarkable capability to survive and disseminate successfully by the acquisition of resistance genes. As a result, the treatment strategies have been severely compromised. Due to the insufficient available data regarding P. aeruginosa resistance from Pakistan, we aimed to investigate the resistance mechanisms of 249 P. aeruginosa strains by antimicrobial susceptibility testing, polymerase chain reaction for the detection of carbapenemases, aminoglycoside resistance genes, extended-spectrum beta-lactamases (ESBLs), sequence typing and plasmid typing. Furthermore, we tested silver nanoparticles (AgNPs) to evaluate their in vitro sensitivity against antimicrobial-resistant P. aeruginosa strains. We observed higher resistance against antimicrobials in the general surgery ward, general medicine ward and wound samples. Phenotypic carbapenemase-producer strains comprised 80.7% (201/249) with 89.0% (179/201) demonstrating genes encoding carbapenemases: blaNDM-1 (32.96%), blaOXA48 (37.43%), blaIMP (7.26%), blaVIM (5.03%), blaKPC-2 (1.12%), blaNDM-1/blaOXA48 (13.97%), blaOXA-48/blaVIM (1.68%) and blaVIM/blaIMP (0.56%). Aminoglycoside-modifying enzyme genes and 16S rRNA methylase variants were detected in 43.8% (109/249) strains: aac(6')-lb (12.8%), aac(3)-lla (12.0%), rmtB (21.1%), rmtC (11.0%), armA (12.8%), rmtD (4.6%), rmtF (6.4%), rmtB/aac(3)-lla (8.2%), rmtB/aac(6')-lla (7.3%) and rmtB/armA (3.6%). In total, 43.0% (77/179) of the strains coharbored carbapenemases and aminoglycoside resistance genes with 83.1% resistant to at least 1 agent in 3 or more classes and 16.9% resistant to every class of antimicrobials tested. Thirteen sequence types (STs) were identified: ST235, ST277, ST234, ST170, ST381, ST175, ST1455, ST1963, ST313, ST207, ST664, ST357 and ST348. Plasmid replicon types IncFI, IncFII, IncA/C, IncL/M, IncN, IncX, IncR and IncFIIK and MOB types F11, F12, H121, P131 and P3 were detected. Meropenem/AgNPs and Amikacin/AgNPs showed enhanced antibacterial activity. We reported the coexistence of carbapenemases and aminoglycoside resistance genes among carbapenem-resistant P. aeruginosa with diverse clonal lineages from Pakistan. Furthermore, we highlighted AgNP's potential role in handling future antimicrobial resistance concerns.

Comprehensive profile of the companion animal gut microbiome integrating reference-based and reference-free methods

The gut microbiome of companion animals is relatively underexplored, despite its relevance to animal health, pet owner health, and basic microbial community biology. Here, we provide the most comprehensive analysis of the canine and feline gut microbiomes to date, incorporating 2639 stool shotgun metagenomes (2272 dog and 367 cat) spanning 14 publicly available datasets (n = 730) and 8 new study populations (n = 1909). These are compared with 238 and 112 baseline human gut metagenomes from the Human Microbiome Project 1-II and a traditionally living Malagasy cohort, respectively, processed in a manner identical to the animal metagenomes. All microbiomes were characterized using reference-based taxonomic and functional profiling, as well as de novo assembly yielding metagenomic assembled genomes clustered into species-level genome bins. Companion animals shared 184 species-level genome bins not found in humans, whereas 198 were found in all three hosts. We applied novel methodology to distinguish strains of these shared organisms either transferred or unique to host species, with phylogenetic patterns suggesting host-specific adaptation of microbial lineages. This corresponded with functional divergence of these lineages by host (e.g. differences in metabolic and antibiotic resistance genes) likely important to companion animal health. This study provides the largest resource to date of companion animal gut metagenomes and greatly contributes to our understanding of the "One Health" concept of a shared microbial environment among humans and companion animals, affecting infectious diseases, immune response, and specific genetic elements.

Boolean model of the gene regulatory network of Pseudomonas aeruginosa CCBH4851

Introduction

Pseudomonas aeruginosa infections are one of the leading causes of death in immunocompromised patients with cystic fibrosis, diabetes, and lung diseases such as pneumonia and bronchiectasis. Furthermore, P. aeruginosa is one of the main multidrug-resistant bacteria responsible for nosocomial infections worldwide, including the multidrug-resistant CCBH4851 strain isolated in Brazil.

Methods

One way to analyze their dynamic cellular behavior is through computational modeling of the gene regulatory network, which represents interactions between regulatory genes and their targets. For this purpose, Boolean models are important predictive tools to analyze these interactions. They are one of the most commonly used methods for studying complex dynamic behavior in biological systems.

Results and discussion

Therefore, this research consists of building a Boolean model of the gene regulatory network of P. aeruginosa CCBH4851 using data from RNA-seq experiments. Next, the basins of attraction are estimated, as these regions and the transitions between them can help identify the attractors, representing long-term behavior in the Boolean model. The essential genes of the basins were associated with the phenotypes of the bacteria for two conditions: biofilm formation and polymyxin B treatment. Overall, the Boolean model and the analysis method proposed in this work can identify promising control actions and indicate potential therapeutic targets, which can help pinpoint new drugs and intervention strategies.

The Prevalence of Metallo-Beta-Lactamese-(MβL)-Producing Pseudomonas aeruginosa Isolates in Brazil: A Systematic Review and Meta-Analysis

The purpose of the current study is to describe the prevalence of Pseudomonas aeruginosa (PA)-producing MβL among Brazilian isolates and the frequency of blaSPM-1 in MβL-PA-producing isolates. From January 2009 to August 2023, we carried out an investigation on this subject in the internet databases SciELO, PubMed, Science Direct, and LILACS. A total of 20 papers that met the eligibility requirements were chosen by comprehensive meta-analysis software v2.2 for data retrieval and analysis by one meta-analysis using a fixed-effects model for the two investigations. The prevalence of MβL-producing P. aeruginosa was 35.8% or 0.358 (95% CI = 0.324-0.393). The studies' differences were significantly different from one another (x2 = 243.15; p < 0.001; I2 = 92.18%), so they were divided into subgroups based on Brazilian regions. There was indication of asymmetry in the meta-analyses' publishing bias funnel plot; so, a meta-regression was conducted by the study's publication year. According to the findings of Begg's test, no discernible publishing bias was found. blaSPM-1 prevalence was estimated at 66.9% or 0.669 in MβL-PA isolates (95% CI = 0.593-0.738). The analysis of this one showed an average heterogeneity (x2 = 90.93; p < 0.001; I2 = 80.20%). According to the results of Begg's test and a funnel plot, no discernible publishing bias was found. The research showed that MβL-P. aeruginosa and SPM-1 isolates were relatively common among individuals in Brazil. P. aeruginosa and other opportunistic bacteria are spreading quickly and causing severe infections, so efforts are needed to pinpoint risk factors, reservoirs, transmission pathways, and the origin of infection.

Endemic High-Risk Clone ST277 Is Related to the Spread of SPM-1-Producing Pseudomonas aeruginosa during the COVID-19 Pandemic Period in Northern Brazil

Pseudomonas aeruginosa is a high-priority bacterial agent that causes healthcare-acquired infections (HAIs), which often leads to serious infections and poor prognosis in vulnerable patients. Its increasing resistance to antimicrobials, associated with SPM production, is a case of public health concern. Therefore, this study aims to determine the antimicrobial resistance, virulence, and genotyping features of P. aeruginosa strains producing SPM-1 in the Northern region of Brazil. To determine the presence of virulence and resistance genes, the PCR technique was used. For the susceptibility profile of antimicrobials, the Kirby-Bauer disk diffusion method was performed on Mueller-Hinton agar. The MLST technique was used to define the ST of the isolates. The exoS+/exoU- virulotype was standard for all strains, with the aprA, lasA, toxA, exoS, exoT, and exoY genes as the most prevalent. All the isolates showed an MDR or XDR profile against the six classes of antimicrobials tested. HRC ST277 played a major role in spreading the SPM-1-producing P. aeruginosa strains.

Exploring the Bacteriome and Resistome of Humans and Food-Producing Animals in Brazil

The epidemiology of antimicrobial resistance (AMR) is complex, with multiple interfaces (human-animal-environment). In this context, One Health surveillance is essential for understanding the distribution of microorganisms and antimicrobial resistance genes (ARGs). This report describes a multicentric study undertaken to evaluate the bacterial communities and resistomes of food-producing animals (cattle, poultry, and swine) and healthy humans sampled simultaneously from five Brazilian regions. Metagenomic analysis showed that a total of 21,029 unique species were identified in 107 rectal swabs collected from distinct hosts, the highest numbers of which belonged to the domain Bacteria, mainly Ruminiclostridium spp. and Bacteroides spp., and the order Enterobacterales. We detected 405 ARGs for 12 distinct antimicrobial classes. Genes encoding antibiotic-modifying enzymes were the most frequent, followed by genes related to target alteration and efflux systems. Interestingly, carbapenemase-encoding genes such as blaAIM-1, blaCAM-1, blaGIM-2, and blaHMB-1 were identified in distinct hosts. Our results revealed that, in general, the bacterial communities from humans were present in isolated clusters, except for the Northeastern region, where an overlap of the bacterial species from humans and food-producing animals was observed. Additionally, a large resistome was observed among all analyzed hosts, with emphasis on the presence of carbapenemase-encoding genes not previously reported in Latin America. IMPORTANCE Humans and food production animals have been reported to be important reservoirs of antimicrobial resistance (AMR) genes (ARGs). The frequency of these multidrug-resistant (MDR) bacteria tends to be higher in low- and middle-income countries (LMICs), due mainly to a lack of public health policies. Although studies on AMR in humans or animals have been carried out in Brazil, this is the first multicenter study that simultaneously collected rectal swabs from humans and food-producing animals for metagenomics. Our results indicate high microbial diversity among all analyzed hosts, and several ARGs for different antimicrobial classes were also found. As far as we know, we have detected for the first time ARGs encoding carbapenemases, such as blaAIM-1, blaCAM-1, blaGIM-2, and blaHMB-1, in Latin America. Thus, our results support the importance of metagenomics as a tool to track the colonization of food-producing animals and humans by antimicrobial-resistant bacteria. In addition, a network surveillance system called GUARANI, created for this study, is ready to be expanded and to collect additional data.

Nielsen SS, Bicout DJ, Calistri P, Canali E, Drewe JA, Garin-Bastuji B, Gonzales Rojas JL, Gortázar C, Herskin M, Michel V, Miranda Chueca MÁ, Padalino B, Pasquali P, Roberts HC, Spoolder H, Ståhl K, Velarde A, Viltrop A, Winckler C, Baldinelli F, Broglia A, Kohnle L, Alvarez J. Assessment of listing and categorisation of animal diseases within the framework of the Animal Health Law (Regulation (EU) No 2016/429): antimicrobial-resistant Pseudomonas aeruginosa in dogs and cats

Pseudomonas aeruginosa (P. aeruginosa) was identified among the most relevant antimicrobial‐resistant (AMR) bacteria in the EU for dogs and cats in a previous scientific opinion. Thus, it has been assessed according to the criteria of the Animal Health Law (AHL), in particular criteria of Article 7 on disease profile and impacts, Article 5 on its eligibility to be listed, Annex IV for its categorisation according to disease prevention and control rules as in Article 9, and Article 8 for listing animal species related to the bacterium. The assessment has been performed following a methodology previously published. The outcome is the median of the probability ranges provided by the experts, which indicates whether each criterion is fulfilled (lower bound ≥ 66%) or not (upper bound ≤ 33%), or whether there is uncertainty about fulfilment. Reasoning points are reported for criteria with uncertain outcome. According to the assessment here performed, it is uncertain whether AMR P. aeruginosa can be considered eligible to be listed for Union intervention according to Article 5 of the AHL (33–90% probability). According to the criteria in Annex IV, for the purpose of categorisation related to the level of prevention and control as in Article 9 of the AHL, the AHAW Panel concluded that the bacterium does not meet the criteria in Sections 1, 2, 3 and 4 (Categories A, B, C and D; 0–5%, 1–5%, 5–33% and 5–33% probability of meeting the criteria, respectively) and the AHAW Panel was uncertain whether it meets the criteria in Section 5 (Category E, 33–90% probability of meeting the criteria). The animal species to be listed for AMR P. aeruginosa according to Article 8 criteria are mainly dogs and cats.

Detection of NDM-5 and MCR-1 antibiotic resistance encoding genes in Enterobacterales in long-distance migratory bird species Ciconia ciconia, Algeria

β-lactams and colistin resistance in Enterobacterales is a global public health issue. In this study we aimed to investigate the occurrence and genetic determinants of Extended-Spectrum β-lactamases, carbapenemases and mcr-encoding-genes in Enterobacterales isolates recovered from the migratory bird species Ciconia ciconia in an Algerian city. A total of 62 faecal samples from white storks were collected. Samples were then subjected to selective isolation of β-lactams and colistin-resistant-Enterobacterales. The representative colonies were identified using Matrix-Assisted Laser Desorption-Ionisation Time-of-Flight Mass Spectrometry. Susceptibility testing was performed using the disk-diffusion method. ESBL, carbapenemases, and colistin resistance determinants were searched for by PCR and sequencing. The clonality relationships of the obtained isolates were investigated by multilocus sequence typing assays. Mating experiments were carried out to evaluate the transferability of the carbapenemase and mcr-genes. Forty-two isolates were identified as follows: Escherichia coli (n = 33), Klebsiella pneumoniae (n = 4), Proteus mirabilis (n = 4) and Citrobacter freundii (n = 1). Molecular analysis showed that twelve isolates carried the bla_ESBL genes alone, fifteen E. coli isolates were positive for the bla_OXA-48 gene, six isolates were NDM-5-carriers (two P. mirabilis, two K. pneumoniae and two E. coli) and eight E. coli strains were positive for the mcr-1 gene. MLST results showed a high clonal diversity, where NDM-5-producing strains were assigned to two sequence types (ST167 for E. coli and ST198 for K. pneumoniae), whereas the mcr-1 positive E. coli isolates belonged to ST58, ST224, ST453, ST1286, ST2973, ST5542, ST9815 and the international high-risk resistant lineage ST101. To the best of our knowledge, this is the first report of bla_NDM-5 gene in white storks and also the first describing the mcr-1 gene in white storks in Algeria. This study underlines the important role of migratory white storks as carriers of high-level drug-resistant bacteria, allowing their possible implication as indicators and sentinels for antimicrobial resistance surveillance.

Genomic Analysis of Carbapenem-Resistant Pseudomonas aeruginosa Isolated From Urban Rivers Confirms Spread of Clone Sequence Type 277 Carrying Broad Resistome and Virulome Beyond the Hospital

The dissemination of antibiotic-resistant priority pathogens beyond hospital settings is both a public health and an environmental problem. In this regard, high-risk clones exhibiting a multidrug-resistant (MDR) or extensively drug-resistant (XDR) phenotype have shown rapid adaptation at the human-animal-environment interface. In this study, we report genomic data and the virulence potential of the carbapenemase, São Paulo metallo-β-lactamase (SPM-1)-producing Pseudomonas aeruginosa strains (Pa19 and Pa151) isolated from polluted urban rivers, in Brazil. Bioinformatic analysis revealed a wide resistome to clinically relevant antibiotics (carbapenems, aminoglycosides, fosfomycin, sulfonamides, phenicols, and fluoroquinolones), biocides (quaternary ammonium compounds) and heavy metals (copper), whereas the presence of exotoxin A, alginate, quorum sensing, types II, III, and IV secretion systems, colicin, and pyocin encoding virulence genes was associated with a highly virulent behavior in the Galleria mellonella infection model. These results confirm the spread of healthcare-associated critical-priority P. aeruginosa belonging to the MDR sequence type 277 (ST277) clone beyond the hospital, highlighting that the presence of these pathogens in environmental water samples can have clinical implications for humans and other animals.

A new mutation in mgrb mediating polymyxin resistance in Klebsiella variicola

Polymyxin resistance is a public health concern - present in humans, animals and the environment - caused by chromosomal-encoding or plasmid-encoding mechanisms. Chromosomal alterations in MgrB are frequently detected in Klebsiella spp., but not yet reported and characterised in Klebsiella variicola (K. variicola). This study performed microbiological and genomic characterisation of three polymyxin-resistant K. variicola isolates (M14, M15 and M50) recovered from the microbiota of migratory birds in Brazil. The isolates were submitted to SpeI-PFGE, broth microdilution and whole genome sequencing using Illumina MiSeq for analysis of genetic relatedness, sequence typing and detection of antimicrobial-resistance genes. K. variicola isolates belonged to two clones, and susceptibility tests showed resistance only for polymyxins. Sequences of chromosomal two-component systems (PmrAB, PhoPQ, RstAB, CrrAB) and MgrB were evaluated by blastN and blastP against a polymyxin-susceptible K. variicola (A58243), and mutations with biological effect were checked by the PROVEAN tool. K. variicola isolates belonged to two clones, and susceptibility tests showed resistance for polymyxins. In M14 and M15, phoQ deleterious mutations (D90N, I122S and G385S) were identified, while an mgrB variant containing a single deletion (C deletion on position 93) leading to the production of a non-functional protein was detected in M50. mgrB complementation studies showed restoration of polymyxin susceptibility (64 to ≤ 0.25 mg/L) as a wild-type mgrB was inserted into the mgrB-deficient M50. This study confirmed the role of a non-functional mgrB variant in conferring polymyxin resistance, stressing the role of this regulator in K. variicola and drawing attention to novel polymyxin resistance mechanisms emerging in wildlife.

Diversity in the composition of the accessory genome of Mexican Pseudomonas aeruginosa strains

BACKGROUND

Pseudomonas aeruginosa is an important opportunistic pathogen especially in nosocomial infections due to its easy adaptation to different environments; this characteristic is due to the great genetic diversity that presents its genome. In addition, it is considered a pathogen of critical priority due to the high antimicrobial resistance.

OBJECTIVES

The aim of this study was to characterize the mobile genetic elements present in the chromosome of six Mexican P. aeruginosa strains isolated from adults with pneumonia and children with bacteremia.

METHODS

The genomic DNA of six P. aeruginosa strains were isolated and sequenced using PacBio RS-II platform. They were annotated using Prokaryotic Genome Annotation Pipeline and manually curated and analyzed for the presence of mobile genetic elements, antibiotic resistances genes, efflux pumps and virulence factors using several bioinformatics programs and databases.

RESULTS

The global analysis of the strains chromosomes showed a novel chromosomal rearrangement in two strains, possibly mediated by subsequent recombination and inversion events. They have a high content of mobile genetic elements: 21 genomic islands, four new islets, four different integrative conjugative elements, 28 different prophages, one CRISPR-Cas arrangements, and one class 1 integron. The acquisition of antimicrobials resistance genes into these elements are in concordance with their phenotype of multi-drug resistance.

CONCLUSION

The accessory genome increased the ability of the strains to adapt or survive to the hospital environment, promote genomic plasticity and chromosomal rearrangements, which may affect the expression or functionality of the gene and might influence the clinical outcome, having an impact on the treatment.

Diversity and Distribution of Resistance Markers in Pseudomonas aeruginosa International High-Risk Clones

Pseudomonas aeruginosa high-risk clones are disseminated worldwide and they are common causative agents of hospital-acquired infections. In this review, we will summarize available data of high-risk P. aeruginosa clones from confirmed outbreaks and based on whole-genome sequence data. Common feature of high-risk clones is the production of beta-lactamases and among metallo-beta-lactamases NDM, VIM and IMP types are widely disseminated in different sequence types (STs), by contrast FIM type has been reported in ST235 in Italy, whereas GIM type in ST111 in Germany. In the case of ST277, it is most frequently detected in Brazil and it carries a resistome linked to bla_SPM. Colistin resistance develops among P. aeruginosa clones in a lesser extent compared to other resistance mechanisms, as ST235 strains remain mainly susceptible to colistin however, some reports described mcr positive P. aeurigonsa ST235. Transferable quinolone resistance determinants are detected in P. aeruginosa high-risk clones and aac(6′)-Ib-cr variant is the most frequently reported as this determinant is incorporated in integrons. Additionally, qnrVC1 was recently detected in ST773 in Hungary and in ST175 in Spain. Continuous monitoring and surveillance programs are mandatory to track high-risk clones and to analyze emergence of novel clones as well as novel resistance determinants.

Update on the epidemiology of carbapenemases in Latin America and the Caribbean

INTRODUCTION

Carbapenemases are β-lactamases able to hydrolyze a wide range of β-lactam antibiotics, including carbapenems. Carbapenemase production in Enterobacterales, Pseudomonas aeruginosa, and Acinetobacter spp., with and without the co-expression of other β-lactamases is a serious public health threat. Carbapenemases belong to three main classes according to the Ambler classification: class A, class B, and class D.

AREAS COVERED

Carbapenemase-bearing pathogens are endemic in Latin America. In this review, we update the status of carbapenemases in Latin America and the Caribbean.

EXPERT OPINION

Understanding the current epidemiology of carbapenemases in Latin America and the Caribbean is of critical importance to improve infection control policies limiting the dissemination of multi-drug-resistant pathogens and in implementing appropriate antimicrobial therapy.

Healthcare-associated carbapenem-resistant OXA-72-producing Acinetobacter baumannii of the clonal complex CC79 colonizing migratory and captive aquatic birds in a Brazilian Zoo

Carbapenem resistance in Acinetobacter baumannii is a public health issue globally, mainly due to the production of carbapenem hydrolyzing class D β-lactamases (CHDLs). In Brazil, OXA-23 and OXA-143 CHDLs have been prevalent in A. baumannii from clinical settings, with some OXA-23 reports in the environmental samples, whereas OXA-72 has begun to be increasingly reported. This study aims to perform the genomic and microbiological characterization of carbapenem-resistant A. baumannii isolates recovered from migratory birds and captive birds inhabiting a lake within a Brazilian Zoo. Four hundred and eighty-one gram-negative bacilli were recovered from choanal and cloacal swabs obtained from 50 migratory birds and 37 captive birds present at the zoo's lake between July and August of 2012. Among all GNB, nine OXA-72-producing A. baumannii were detected from the microbiota of four migratory and five captive aquatic birds. The OXA-72-producing A. baumannii isolates were submitted to antimicrobial susceptibility test and PFGE, exhibiting a multidrug-resistant profile and clonal relatedness with OXA-72-positive human isolates circulating for eighteen years in a hospital setting. MLST, plasmid analysis and whole-genome sequencing revealed which all carbapenem-resistant A. baumannii from bird and human hosts belonged to clonal complex 79, and harboured a small plasmid (⁓16.6-kb in size), named pAC1-BRL, which carried bla_OXA-72 gene, macrolide resistance genes msrE and mphE, and the toxin-antitoxin system AbkAB. To determine the impact of pAC1-BRL acquisition in the the capacity of a microorganism to survive in a competitive environment (in the following called fitness), the laboratory strain A. baumannii ATCC 19606 was used in the fitness experiments and suggested an increase of its relative fitness after the pAC1-BRL acquisition. In summary, the detection of OXA-72-producing A. baumannii strains belonging to CC79 in aquatic birds is a piece of epidemiological evidence demonstrating that dissemination of high-risk bacteria is extending beyond the hospital.

The Current Burden of Carbapenemases: Review of Significant Properties and Dissemination among Gram-Negative Bacteria

Carbapenemases are β-lactamases belonging to different Ambler classes (A, B, D) and can be encoded by both chromosomal and plasmid-mediated genes. These enzymes represent the most potent β-lactamases, which hydrolyze a broad variety of β-lactams, including carbapenems, cephalosporins, penicillin, and aztreonam. The major issues associated with carbapenemase production are clinical due to compromising the activity of the last resort antibiotics used for treating serious infections, and epidemiological due to their dissemination into various bacteria across almost all geographic regions. Carbapenemase-producing Enterobacteriaceae have received more attention upon their first report in the early 1990s. Currently, there is increased awareness of the impact of nonfermenting bacteria, such as Acinetobacter baumannii and Pseudomonas aeruginosa, as well as other Gram-negative bacteria that are carbapenemase-producers. Outside the scope of clinical importance, carbapenemases are also detected in bacteria from environmental and zoonotic niches, which raises greater concerns over their prevalence, and the need for public health measures to control consequences of their propagation. The aims of the current review are to define and categorize the different families of carbapenemases, and to overview the main lines of their spread across different bacterial groups.

Exploring the success of Brazilian endemic clone Pseudomonas aeruginosa ST277 and its association with the CRISPR-Cas system type I-C

BACKGROUND

The Brazilian endemic clone Pseudomonas aeruginosa ST277 carries important antibiotic resistance determinants, highlighting the gene coding for SPM-1 carbapenemase. However, the resistance and persistence of this clone is apparently restricted to the Brazilian territory. To understand the differences between Brazilian strains from those isolated in other countries, we performed a phylogenetic analysis of 47 P. aeruginosa ST277 genomes as well as analyzed the virulence and resistance gene profiles. Furthermore, we evaluated the distribution of genomic islands and assessed in detail the characteristics of the CRISPR-Cas immunity system in these isolates.

RESULTS

The Brazilian genomes presented a typical set of resistance and virulence determinants, genomic islands and a high frequency of the CRISPR-Cas system type I-C. Even though the ST277 genomes are closely related, the phylogenetic analysis showed that the Brazilian strains share a great number of exclusively SNPs when compared to other ST277 genomes. We also observed a standard CRISPR spacers content for P. aeruginosa ST277, confirming a strong link between sequence type and spacer acquisition. Most CRISPR spacer targets were phage sequences.

CONCLUSIONS

Based on our findings, P. aeruginosa ST277 strains circulating in Brazil characteristically acquired In163 and PAGI-25, which can distinguish them from strains that do not accumulate resistance mechanisms and can be found on the Asian, European and North American continents. The distinctive genetic elements accumulated in Brazilian samples can contribute to the resistance, pathogenicity and transmission success that characterize the ST277 in this country.