Spread of Multidrug-ResistantEnterococcus faecalisWithin the Household Setting

Canine uropathogenic and avian pathogenic Escherichia coli harboring conjugative plasmids exhibit augmented growth and exopolysaccharide production in response to Enterococcus faecalis

Uropathogenic Escherichia coli (UPEC) and avian pathogenic Escherichia coli (APEC) are extraintestinal pathogenic Escherichia coli (ExPEC) that infect dogs and poultry. These agents occur both as single-species infections and, commonly, in co-infection with Enterococcus faecalis (EF); however, it is unclear how EF co-infections modulate ExPEC virulence. Genetic drivers of interspecies interactions affecting virulence were identified using macrocolony co-culture, chicken embryo co-infection experiments, and whole-genome sequence analysis of ExPEC and EF clinical isolates. Ten of 11 UPEC strains originally co-isolated with EF exhibited a growth advantage when co-cultured with EF on iron-limited, semi-solid media in contrast to growing alone (P < 0.01). Phylogenetic analyses of these UPEC and 18 previously screened APEC indicated the growth-response phenotype was conserved in ExPEC despite strain diversity. When genomes of EF-responsive ExPEC were compared to non-responsive ExPEC genomes, EF-induced growth was associated with siderophore, exopolysaccharide (EPS), and plasmid conjugative transfer genes. Two matched pairs of EF-responsive and non-responsive ExPEC were selected for further characterization by macrocolony proximity and chicken embryo lethality assays. EF-responsive ExPEC produced 5 to 16 times more EPS in proximity to EF and were more lethal to embryos alone and during co-infection with EF compared to non-responsive ExPEC (P < 0.05). A responsive APEC strain cured of its conjugative plasmid lost the enhanced growth and EPS production response to EF. These data demonstrate that ExPEC growth augmentation by EF occurs in UPEC and APEC strains and is linked to conjugative virulence plasmids and EPS production, which are widely conserved ExPEC virulence determinants.

The use of metronidazole in acute diarrhea in dogs: a narrative review

Acute diarrhea is a common reason for non-wellness veterinary visits in dogs. Treatment for acute diarrhea usually consists of supportive care with nutritional intervention, fluid therapy, anthelmintics, and often an antibiotic - commonly metronidazole in North America. The empirical use of metronidazole for acute diarrhea in dogs has been a common practice in veterinary medicine for many decades; however, recent studies evaluating its use suggest it may be inappropriately utilized in many cases. Herein, we review the evidence evaluating the use of metronidazole and other antibiotics in acute diarrhea in the human and veterinary literature. Recommendations on the use of metronidazole and other antibiotics as well as other therapeutic considerations in the treatment of acute diarrhea are also provided.

Dissemination of Enterococcal Genetic Lineages: A One Health Perspective

Enterococcus spp. are commensals of the gastrointestinal tracts of humans and animals and colonize a variety of niches such as water, soil, and food. Over the last three decades, enterococci have evolved as opportunistic pathogens, being considered ESKAPE pathogens responsible for hospital-associated infections. Enterococci's ubiquitous nature, excellent adaptative capacity, and ability to acquire virulence and resistance genes make them excellent sentinel proxies for assessing the presence/spread of pathogenic and virulent clones and hazardous determinants across settings of the human-animal-environment triad, allowing for a more comprehensive analysis of the One Health continuum. This review provides an overview of enterococcal fitness and pathogenic traits; the most common clonal complexes identified in clinical, veterinary, food, and environmental sources; as well as the dissemination of pathogenic genomic traits (virulome, resistome, and mobilome) found in high-risk clones worldwide, across the One Health continuum.

Transmission routes of antibiotic resistant bacteria: a systematic review

Background

Quantification of acquisition routes of antibiotic resistant bacteria (ARB) is pivotal for understanding transmission dynamics and designing cost-effective interventions. Different methods have been used to quantify the importance of transmission routes, such as relative risks, odds ratios (OR), genomic comparisons and basic reproduction numbers. We systematically reviewed reported estimates on acquisition routes’ contributions of ARB in humans, animals, water and the environment and assessed the methods used to quantify the importance of transmission routes.

Methods

PubMed and EMBASE were searched, resulting in 6054 articles published up until January 1st, 2019. Full text screening was performed on 525 articles and 277 are included.

Results

We extracted 718 estimates with S. aureus (n = 273), E. coli (n = 157) and Enterobacteriaceae (n = 99) being studied most frequently. Most estimates were derived from statistical methods (n = 560), mainly expressed as risks (n = 246) and ORs (n = 239), followed by genetic comparisons (n = 85), modelling (n = 62) and dosage of ARB ingested (n = 17). Transmission routes analysed most frequently were occupational exposure (n = 157), travelling (n = 110) and contacts with carriers (n = 83). Studies were mostly performed in the United States (n = 142), the Netherlands (n = 87) and Germany (n = 60). Comparison of methods was not possible as studies using different methods to estimate the same route were lacking. Due to study heterogeneity not all estimates by the same method could be pooled.

Conclusion

Despite an abundance of published data the relative importance of transmission routes of ARB has not been accurately quantified. Links between exposure and acquisition are often present, but the frequency of exposure is missing, which disables estimation of transmission routes’ importance. To create effective policies reducing ARB, estimates of transmission should be weighed by the frequency of exposure occurrence.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07360-z.

Genetic Diversity, Biofilm Formation, and Antibiotic Resistance of Pseudomonas aeruginosa Isolated from Cow, Camel, and Mare with Clinical Endometritis

Pseudomonas aeruginosa is a ubiquitous opportunistic bacterium that causes diseases in animals and humans. This study aimed to investigate the genetic diversity, antimicrobial resistance, biofilm formation, and virulence and antibiotic resistance genes of P. aeruginosa isolated from the uterus of cow, camel, and mare with clinical endometritis and their drinking water. Among the 180 uterine swabs and 90 drinking water samples analysed, 54 (20%) P. aeruginosa isolates were recovered. Isolates were identified biochemically to the genus level by the automated Vitek 2 system and genetically by the amplification of the gyrB gene and the sequencing of the 16S rRNA gene. Multilocus sequence typing identified ten different sequence types for the P. aeruginosa isolates. The identification of ST2012 was significantly (p ≤ 0.05) higher than that of ST296, ST308, ST111, and ST241. The isolates exhibited significantly (p ≤ 0.05) increased resistance to piperacillin (77.8%), ciprofloxacin (59.3%), gentamicin (50%), and ceftazidime (38.9%). Eight (14.8%) isolates showed resistance to imipenem; however, none of the isolates showed resistance to colistin. Multidrug resistance (MDR) was observed in 24 isolates (44.4%) with a multiple antibiotic resistance index ranging from 0.44 to 0.77. MDR was identified in 30 (33.3%) isolates. Furthermore, 38.8% and 9.2% of the isolates exhibited a positive extended-spectrum-β-lactamase (ESBL) and metallo-β-lactamase (MBL) phenotype, respectively. The most prevalent β-lactamase encoding genes were bla_TEM and bla_CTX-M, however, the bla_IPM gene was not detected in any of the isolates. Biofilm formation was observed in 49 (90.7%) isolates classified as: 11.1% weak biofilm producers; 38.9% moderate biofilm producers; 40.7% strong biofilm producers. A positive correlation was observed between the MAR index and biofilm formation. In conclusion, the results highlighted that farm animals with clinical endometritis could act as a reservoir for MDR and virulent P. aeruginosa. The emergence of ESBLs and MBLs producing P. aeruginosa in different farm animals is a public health concern. Therefore, surveillance programs to monitor and control MDR P. aeruginosa in animals are required.

A comparison of rectal and oral cultivable microbiota in wild and captive black lion tamarins (Leontopithecus chrysopygus, Mikan 1823)

The black lion tamarin (Leontopithecus chrysopygus) is an endangered primate species, restricted to the Atlantic Forest fragments of São Paulo state, Brazil, with an estimated wild population of ~1600 individuals. Integrative studies between zoo (ex situ) and wild (in situ) animals are crucial to modern conservation programs. They can demonstrate a substantial impact with the One Health concept, an interdisciplinary research frontier regarding the relations between human, animal, and environmental health. Studies of wild populations of Leontopithecus spp. are scarce and should be encouraged to provide baseline information to develop preventive and curative medicine in zoos and other conservation programs. Studying these animals in the wild can offer important reference parameters for the species. Comparing bacterial communities between in situ and ex situ populations can help us understand both conditions and the dynamics of potentially pathogenic microorganisms. To increase our understanding of resident microorganisms among these groups, we collected oral and rectal samples from captive (zoo) and wild black lion tamarins. We employed a culture method for the identification of aerobic bacteria. Thirty-three specimens were sampled (24 zoo and 8 wild animals) and 18 bacterial genera were identified. We found primarily Gram-positive bacteria in wild animals, whereas in zoo animals, Gram-negative bacteria were dominant. Some of the bacterial species we identified are potentially pathogenic, whereas several others are being reported here for the first time in this host species. Our results reinforce the importance of integrative studies for the future management and conservation of this endangered primate species.

Pet husbandry as a risk factor for colonization or infection with MDR organisms: a systematic meta-analysis

BACKGROUND

MDR organisms (MDROs) pose a relevant risk for patients in modern healthcare. Although ownership of pet animals is common and owners and pets commonly live in close contact, it is still unclear whether pet ownership may be considered as a risk factor for MDRO acquisition prior to hospitalization.

METHODS

We performed three separate meta-analyses in accordance with the PRISMA guidelines, assessing contact to pets as a risk factor for acquisition of MRSA, VRE and MDR Gram-negatives [namely third-generation cephalosporin-resistant Enterobacterales (3GCRE) and carbapenem-resistant Enterobacterales (CRE)].

RESULTS

We calculated an increased risk of MRSA carriage for dog owners [risk ratio (RR) 2.28, 95% CI 1.47-3.56]. Meta-analysis did not show a significantly higher risk for 3GCRE colonization among owners of different pet species compared with non-pet owners (RR 1.18, 95% CI 0.83-1.68 for pet owners in general, RR 0.88, 95% CI 0.56-1.40 for dog owners, RR 1.16, 95% CI 0.58-2.34 for cat owners, RR 1.34, 95% CI 0.43-4.18 for rodent owners, RR 0.91, 95% CI 0.38-2.18 for bird owners, and RR 2.34, 95% CI 0.33-16.63 for lizard/frog owners). For VRE, there were insufficient data to perform a meta-analysis.

CONCLUSIONS

Our analyses suggest contact to pet animals is a risk factor for MRSA, but not for 3GCRE/CRE acquisition. Evaluation of the underlying literature suggested a possible role of pet animals as: (i) vectors for the transmission of MDROs between livestock and humans; as well as (ii) a reservoir for MDROs. Pets, therefore, may promote transmission and reinfection of humans.

Impact of European pet antibiotic use on enterococci and staphylococci antimicrobial resistance and human health

Due to the inappropriate use of antibiotics described in both human and veterinary medicine, there is emerging evidence of antimicrobial-resistant organisms isolated from humans and pets, forming a multifaceted problem. Although the true magnitude of antimicrobial resistance in pets and other animals, as well as humans, are not fully known; pets, in particular dogs and cats, can contribute to the spread of antimicrobial resistance due to close contact with humans and their status as a family member in urban households. This review summarizes and highlights the current data concerning the antibiotic use on pets, and the European distribution of the increasing prevalence of multiresistant bacterial pathogens, such as enterococci and methicillin-resistant staphylococci on pets, as well as its implications for public health.

Antimicrobial Prescribing Practices in Small Animal Emergency and Critical Care

Background: Antimicrobial use contributes to emergence of antimicrobial resistance. It was hypothesized that antimicrobial prescribing behavior varies between the emergency (ER) and critical care (CC) services in a veterinary teaching hospital. This study aimed to: (i) describe antimicrobial prescribing patterns in the ER and CC services; (ii) assess adherence to stewardship principles; (iii) evaluate the prevalence of multidrug resistant (MDR) bacterial isolates. Methods: Institution electronic medical records were queried for all antimicrobial prescriptions from the ER and CC services between 1/1/2017 and 12/31/2017. Prescriptions were manually reviewed, and the following data recorded: drug, dosage, duration, diagnosis, outcome, hospitalization duration, culture submission, and susceptibility results. Results: There were 5,091 ER visits, of which 3,125 were not transferred to another service. Of these emergency visits, 516 (16.5%) resulted in 613 antimicrobial drug prescriptions. The most commonly prescribed drugs for the ER were amoxicillin/clavulanate (n = 243, 39.6%), metronidazole (n = 146, 23.8%), and ampicillin/sulbactam (n = 55, 9.0%). The most common reasons for antimicrobial prescriptions were skin disease (n = 227, 37.0%), gastrointestinal disease (n = 173, 28.2%), and respiratory disease (n = 50, 8.2%). For ER patients 18 cultures were submitted, equivalent to a 3.5% submission rate. The CC service managed 311 case visits for 822 patient days. Of these, 133 case visits (42.7%) resulted in 340 prescriptions. The most commonly prescribed drugs for the CC service were ampicillin/sulbactam (n = 103, 30.3%), enrofloxacin (n = 75, 22.1%), and metronidazole (n = 59, 17.4%). The most common reasons for antimicrobial prescriptions were gastrointestinal disease (n = 106, 31.2%), respiratory disease (n = 71, 20.9%), and sepsis (n = 61, 17.9%). On the CC service, 46 patients had ≥1 culture submitted, equivalent to a 34.6% submission rate. Of patients prescribed antimicrobials, 13/38 (34%) with urinary tract disease, 2/28 (7%) with pneumonia, 1/11 (9%) with canine infectious respiratory disease complex and 2/8 (25%) with feline upper respiratory infection were compliant with published guidelines. Conclusions: Antimicrobial prescription was common in both ER and CC services and followed similar patterns. Adherence to published guidelines for urinary and respiratory infections was poor.

Hospitalized Pets as a Source of Carbapenem-Resistance

The massive and irrational use of antibiotics in livestock productions has fostered the occurrence and spread of resistance to “old class antimicrobials.” To cope with that phenomenon, some regulations have been already enforced in the member states of the European Union. However, a role of livestock animals in the relatively recent alerts on the rapid worldwide increase of resistance to last-choice antimicrobials as carbapenems is very unlikely. Conversely, these antimicrobials are increasingly administered in veterinary hospitals whose role in spreading bacteria or mobile genetic elements has not adequately been addressed so far. A cross-sectional study was carried out on 105 hospitalized and 100 non-hospitalized pets with the aim of measuring the prevalence of carbapenem-resistant Gram-negative bacteria (GNB) colonizing dogs and cats, either hospitalized or not hospitalized and estimating the relative odds. Stool samples were inoculated on MacConkey agar plates containing 1 mg/L imipenem which were then incubated aerobically at 37°C ± 1 for 48 h. Isolated bacteria were identified first by Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and were confirmed by 16S rRNA sequencing. The genetic basis of resistance was investigated using PCR methods, gene or whole genome sequencing (WGS). The prevalence of pets harboring carbapenem-resistant bacteria was 11.4 and 1.0% in hospitalized and not-hospitalized animals, respectively, with an odds ratio of 12.8 (p < 0.01). One pet carried two diverse isolates. Overall, 14 gram-negative non-fermenting bacteria, specifically, one Acinetobacter radioresistens, five Acinetobacter baumannii, six Pseudomonas aeruginosa and two Stenotrophomonas maltophilia were isolated. The Acinetobacter species carried acquired carbapenemases genes encoded by bla_NDM-1 and bla_OXA-23. In contrast, Pseudomonas phenotypic resistance was associated with the presence of mutations in the oprD gene. Notably, inherent carbapenem-resistant isolates of S. maltophilia were also resistant to the first-line recommended chemotherapeutic trimethoprim/sulfamethoxazole. This study estimates the risk of colonization by carbapenem-resistant non-fermenting GNB in pets hospitalized in veterinary tertiary care centers and highlights their potential role in spreading resistance genes among the animal and human community. Public health authorities should consider extending surveillance systems and putting the release of critical antibiotics under more strict control in order to manage the infection/colonization of pets in veterinary settings.

Virulence and antimicrobial resistance factors of Enterococcusspp. isolated from fecal samples from piggery farms in Eastern Cape, South Africa

Background

Enterococci have emerged as an important opportunistic pathogen causing life-threatening infections in hospitals. The emergence of this pathogen is associated with a remarkable capacity to accumulate resistance to antimicrobials and multidrug-resistance particularly to vancomycin, erythromycin and streptomycin have become a major cause of concern for the infectious diseases community. In this paper, we report the prevalence of Enterococcus in respect to species distribution, their virulence and antibiogram profiles.

Methods

Four hundred fecal samples were collected from two piggery farms in the Eastern Cape Province of South Africa. Enterococcus species were isolated and confirmed with generic specific primers targeting the tuf gene (encoding elongation factor). The confirmed isolates were speciated with enterococci species specific primers that aimed at delineating them into six species that are commonly associated with infections in humans. Antibiotic susceptibility testing was performed by disc diffusion method. Six virulence genes and antimicrobial resistance profiles of the isolates were evaluated molecularly.

Results

Molecular identification of the presumptive isolates confirmed 320 isolates as Enterococcus spp. Attempt at speciation of the isolates with primers specific for E. faecalis, E. durans, E. casseliflavus, E. hirae and E. faecium delineated them as follows: E. faecalis (12.5 %), E. hirae (31.25 %), E. durans (18.75 %) and E. faecium (37.5 %) while E. casseliflavus was not detected. All the isolates were resistant to vancomycin, streptomycin and cloxacillin, and to at least two different classes of antibiotics, with 300 (93.8 %) isolates being resistant to five or more antibiotics. Also, three out of the six virulence genes were detected in majority of the isolates and they are Adhesion of collagen in E. faecalis (ace) (96.88 %), gelatinase (gelE) (93.13 %) and surface protein (esp) (67.8 %).

Conclusion

There was high prevalence of multi-resistant vancomycin Enterococcus spp. (VREs) in the fecal samples of pigs in the farms studied, and this poses health implications as vancomycin is an important drug in human medicine. Further studies are needed to determine the spread of vancomycin resistance among bacteria of human origin in the communities.

Prevalence of antimicrobial resistance in faecal enterococci from vet-visiting pets and assessment of risk factors

The objective of this study was to determine the prevalence of antimicrobial resistance (AMR) exhibited by enterococci isolated from faeces of pets and its underlying risk factors. From September 2009 to May 2012, rectal swabs were collected from 74 dogs and 17 cats, selected from the population of animals visiting the Veterinary Hospital of University of Porto, UPVet, through a systematic random procedure. Animal owners answered a questionnaire about the risk factors that could influence the presence of AMR in faecal enterococci. Enterococci isolation, identification and antimicrobial (AM) susceptibility testing were performed. Data analyses of multilevel, univariable and multivariable generalised linear mixed models were conducted. From all enterococci isolated (n=315), 61 per cent were considered multidrug-resistant, whereas only 9.2 per cent were susceptible to all AMs tested. Highest resistance was found to tetracycline (67.0 per cent), rifampicin (60.3 per cent), azithromycin (58.4 per cent), quinupristin/dalfopristin (54.0 per cent) and erythromycin (53.0 per cent). Previous fluoroquinolone treatments and coprophagic habits were the features more consistently associated with the presence of AMR for three (chloramphenicol, ciprofloxacin and azithromycin) and seven (tetracycline, rifampicin, gentamicin, chloramphenicol, ciprofloxacin, erythromycin and azithromycin), respectively, out of nine AMs assessed. Evaluating risk factors that determine the presence of drug-resistant bacteria in pets, a possible source of resistance determinants to human beings, is crucial for the selection of appropriate treatment guidelines by veterinary practitioners.

Molecular characterization of quinolone resistance mechanisms and extended-spectrum β-lactamase production in Escherichia coli isolated from dogs

The increasing prevalence of antimicrobial resistances is now a worldwide problem. Investigating the mechanisms by which pets harboring resistant strains may receive and/or transfer resistance determinants is essential to better understanding how owners and pets can interact safely. Here, we characterized the genetic determinants conferring resistance to β-lactams and quinolones in 38 multidrug-resistant Escherichia coli isolated from fecal samples of dogs, through PCR and sequencing. The most frequent genotype included the β-lactamase groups TEM (n=5), and both TEM+CTX-M-1 (n=5). Within the CTX-M group, we identified the genes CTX-M-32, CTX-M-1, CTX-M-15, CTX-M-55/79, CTX-M-14 and CTX-M-2/44. Thirty isolates resistant to ciprofloxacin presented two mutations in the gyrA gene and one or two mutations in the parC gene. A mutation in gyrA (reported here for the first time), due to a transversion and transition (TCG→GTG) originating a substitution of a serine by a valine in position 83 was also detected. The plasmid-encoded quinolone resistance gene, qnrs1, was detected in three isolates. Dogs can be a reservoir of genetic determinants conferring antimicrobial resistance and thus may play an important role in the spread of antimicrobial resistance to humans and other co-habitant animals.