Previous studies showed that circulating autoantibodies against M2 muscarinic receptors (anti-M2R Ab) are associated with decreased cardiac parasympathetic modulation in patients with chronic Chagas ...disease (CD). Here we investigated whether the exposure of M2R to such antibodies could impair agonist-induced receptor activation, leading to the inhibition of associated signaling pathways. Preincubation of M2R-expressing HEK 293T cells with serum IgG fractions from chagasic patients with cardiovascular dysautonomia, followed by the addition of carbachol, resulted in the attenuation of agonist-induced Gi protein activation and arrestin-2 recruitment. These effects were not mimicked by the corresponding Fab fractions, suggesting that they occur through receptor crosslinking. IgG autoantibodies did not enhance M2R/arrestin interaction or promote M2R internalization, suggesting that their inhibitory effects are not likely a result of short-term receptor regulation. Rather, these immunoglobulins could function as negative allosteric modulators of acetylcholine-mediated responses, thereby contributing to the development of parasympathetic dysfunction in patients with CD.
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•The role of serum autoantibodies in Chagas disease-related dysautonomia was examined.•M2 muscarinic receptor antibodies inhibit agonist-induced Gi protein activation.•These antibodies also inhibit agonist-mediated arrestin-2 recruitment.•Anti-M2 receptor autoantibodies could function as negative allosteric modulators.•These autoantibodies could play a pathogenic role in chagasic dysautonomia.
There is scarce information concerning the role of sporadic clones in the dissemination of antimicrobial resistance genes (ARGs) within the nosocomial niche. We confirmed that the clinical
M19736 ...ST615 strain, one of the first isolates of Latin America that harbors a plasmid with an
gene, could receive crucial ARG by transformation and conjugation using as donors critical plasmids that harbor
,
,
,
, or
genes.
M19736 acquired
,
,
,
, and
genes, being only blaNDM-1 maintained at 100% on the 10th day of subculture. In addition, when the evolved MDR-
M19736 acquired sequentially
and
genes, the maintenance pattern of the plasmids changed. In addition, when the evolved XDR-
M19736 acquired in an ulterior step the paadB plasmid, a different pattern of the plasmid's maintenance was found. Interestingly, the evolved
M19736 strains disseminated simultaneously the acquired conjugative plasmids in different combinations though selection was ceftazidime in all cases. Finally, we isolated and characterized the extracellular vesicles (EVs) from the native and evolved XDR-
M19736 strains. Interestingly, EVs from the evolved XDR-
M19736 harbored
though the pDCAG1-CTX-M-15 was previously lost as shown by WGS and experiments, suggesting that EV could be a relevant reservoir of ARG for susceptible bacteria. These results evidenced the genetic plasticity of a sporadic clone of
such as ST615 that could play a relevant transitional link in the clinical dynamics and evolution to multidrug/extensively/pandrug-resistant phenotypes of superbugs within the nosocomial niche by acting simultaneously as a vector and reservoir of multiple ARGs which later could be disseminated.
Two metallo-β-lactamase-producing
Klebsiella pneumoniae
(HA30 and HA31) were isolated in a hospital in Argentina during 2018.
K. pneumoniae
HA30 was isolated from a rectal swab during the ...epidemiological surveillance for carbapenemase-producing strains, while
K. pneumoniae
HA31 was collected from the same patient 4 days after hospitalization. The aim of the present study was to identify the clonal relationships and resistome of these two NDM-producing
K. pneumoniae
strains isolated from a patient with a fatal outcome. Whole-genome sequencing (WGS) was performed using Illumina MiSeq-I, and subsequent analysis involved genome assembly, annotation, antibiotic resistance gene identification, multilocus sequence typing (MLST), and plasmid characterization using bioinformatics tools. Conjugation assays to
E. coli
J53 was conducted as previously described.
K. pneumoniae
HA30 exhibited extensively drug-resistant phenotype, while HA31 was multidrug-resistant as defined by Magiorakos et al., including both resistance to carbapenems, aminoglycosides and ciprofloxacin with
bla
NDM-5
,
bla
CTX-M-15
and
rmtB
genes found in both strains. MLST analysis showed that both strains belonged to ST11, differing by only 4 cgSNPs, indicating that
K. pneumoniae
HA30 and HA31 were the same strain. Conjugation assays revealed that
K. pneumoniae
HA31 strain possessed a transferable plasmid to
E. coli
J53. Bioinformatics studies identified that the same strain colonizing an inpatient during hospital admission subsequently caused the infection leading to a fatal outcome, being the first report of
bla
NDM-5
,
rmtB
and
bla
CTX-M-15
genes in a
K. pneumoniae
ST11 strain from Latin America. Our results also highlighted the importance of focusing on epidemiological surveillance programs.
The worldwide dissemination of carbapenemase-producing Escherichia coli lineages belonging to high-risk clones poses a challenging public health menace. The aim of this work was to investigate ...genomic features of a colonizing multidrug-resistant strain of Klebsiella pneumoniae carbapenemase (KPC)-producing E. coli from our institution.
Whole-genome sequencing was done by Illumina MiSeq-I, and de novo assembly was achieved using SPAdes. Resistome, mobilome, plasmids, virulome, and integrons were analysed using ResFinder, AMRFinder, ISFinder, PlasmidFinder, MOB-suite, VirulenceFinder, and IntegronFinder. Sequence types (STs) were identified with pubMLST and BIGSdb databases. Conjugation assays were also performed.
Escherichia coli HA25pEc was isolated from a rectal swab sample taken within the framework of the hospital epidemiological surveillance protocol for detection of carbapenemase-producing Enterobacterales. Escherichia coli HA25pEc corresponded to the first report of ST648 co-harbouring blaKPC-2 and blaCTX-M-15 in Latin America from a colonized patient. It had 19 antibiotic resistance genes (ARGs), including blaKPC-2, located on a Tn4401a isoform. Conjugation assays revealed that blaKPC-2 was not transferred by conjugation to E. coli J53 under our experimental conditions.
Escherichia coli ST648 has been detected previously in companion and farm animals as well as in hospital- and community-acquired infections worldwide. Although scarcely reported as KPC-producers, our finding in a culture surveillance with several acquired ARGs, including blaCTX-M-15, alerts the potential of this clone for worldwide unnoticed spreading of extreme drug resistance to β-lactams. These data reinforce the importance of carrying out molecular surveillance to identify reservoirs and warn about the dissemination of new international clones in carbapenemase-bearing patients.
The worldwide dissemination of carbapenemase-producing Escherichia coli lineages belonging to high-risk clones poses a challenging public health menace. The aim of this work was to investigate ...genomic features of a colonizing multidrug-resistant strain of Klebsiella pneumoniae carbapenemase (KPC)-producing E. coli from our institution.
Whole-genome sequencing was done by Illumina MiSeq-I, and de novo assembly was achieved using SPAdes. Resistome, mobilome, plasmids, virulome, and integrons were analysed using ResFinder, AMRFinder, ISFinder, PlasmidFinder, MOB-suite, VirulenceFinder, and IntegronFinder. Sequence types (STs) were identified with pubMLST and BIGSdb databases. Conjugation assays were also performed.
Escherichia coli HA25pEc was isolated from a rectal swab sample taken within the framework of the hospital epidemiological surveillance protocol for detection of carbapenemase-producing Enterobacterales. Escherichia coli HA25pEc corresponded to the first report of ST648 co-harbouring bla
and bla
in Latin America from a colonized patient. It had 19 antibiotic resistance genes (ARGs), including bla
, located on a Tn4401a isoform. Conjugation assays revealed that bla
was not transferred by conjugation to E. coli J53 under our experimental conditions.
Escherichia coli ST648 has been detected previously in companion and farm animals as well as in hospital- and community-acquired infections worldwide. Although scarcely reported as KPC-producers, our finding in a culture surveillance with several acquired ARGs, including bla
, alerts the potential of this clone for worldwide unnoticed spreading of extreme drug resistance to β-lactams. These data reinforce the importance of carrying out molecular surveillance to identify reservoirs and warn about the dissemination of new international clones in carbapenemase-bearing patients.
Previous studies showed that circulating autoantibodies against M
muscarinic receptors (anti-M
R Ab) are associated with decreased cardiac parasympathetic modulation in patients with chronic Chagas ...disease (CD). Here we investigated whether the exposure of M
R to such antibodies could impair agonist-induced receptor activation, leading to the inhibition of associated signaling pathways. Preincubation of M
R-expressing HEK 293T cells with serum IgG fractions from chagasic patients with cardiovascular dysautonomia, followed by the addition of carbachol, resulted in the attenuation of agonist-induced G
protein activation and arrestin-2 recruitment. These effects were not mimicked by the corresponding Fab fractions, suggesting that they occur through receptor crosslinking. IgG autoantibodies did not enhance M
R/arrestin interaction or promote M
R internalization, suggesting that their inhibitory effects are not likely a result of short-term receptor regulation. Rather, these immunoglobulins could function as negative allosteric modulators of acetylcholine-mediated responses, thereby contributing to the development of parasympathetic dysfunction in patients with CD.
Escherichia coli is an important cause of septicemia (SEPEC) and neonatal meningitis (NMEC) in dairy calves. However, the diversity of virulence profiles, phylogroups, antimicrobial resistance ...patterns, carriage of integron structures, and fluoroquinolone (FQ) resistance mechanisms have not been fully investigated. Also, there is a paucity of knowledge about the virulence profiles and frequency of potential SEPEC in feces from calves with or without diarrhea. This study aimed to characterize the virulence potential, phylogroups, antimicrobial susceptibility, integron content, and FQ-resistance mechanisms in Escherichia coli isolated from calves with meningitis and septicemia. Additionally, the virulence genes (VGs) and profiles of E. coli isolated from diarrheic and non-diarrheic calves were compared between them and together with NMEC and SEPEC in order to identify shared profiles. Tissue and fluid samples from eight dairy calves with septicemia, four of which had concurrent meningitis, were processed for bacteriology and histopathology. Typing of VGs was assessed in 166 isolates from diverse samples of each calf. Selected isolates were evaluated for antimicrobial susceptibility by the disk diffusion test. Phylogroups, integron gene cassettes cartography, and FQ-resistance determinants were analyzed by PCR, sequencing, and bioinformatic tools. Furthermore, 109 fecal samples and 700 fecal isolates from dairy calves with or without diarrhea were evaluated to detect 19 VGs by uniplex PCR. Highly diverse VG profiles were characterized among NMEC and SEPEC isolates, but iucD was the predominant virulence marker. Histologic lesions in all calves supported their pathogenicity. Selected isolates mainly belonged to phylogroups A and C and showed multidrug resistance. Classic (dfrA17 and arr3-dfrA27) and complex (dfrA17-aadA5::ISCR1::blaCTX-M-2) class 1 integrons were identified. Target-site mutations in GyrA (S83L and D87N) and ParC (S80I) encoding genes were associated with FQ resistance. The VGs detected more frequently in fecal samples included f17G (50%), papC (30%), iucD (20%), clpG (19%), eae (16%), and afaE-8 (13%). Fecal isolates displaying the profiles of f17 or potential SEPEC were found in 25% of calves with and without diarrhea. The frequency of E. coli VGs and profiles did not differ between both groups (p > 0.05) and were identical or similar to those found in NMEC and SEPEC. Overall, multidrug-resistant E. coli isolates with diverse VG profiles and belonging to phylogroups A and C can be implicated in natural cases of meningitis and septicemia. Their resistance phenotypes can be partially explained by class 1 integron gene cassettes and target-site mutations in gyrA and parC. These results highlight the value of antimicrobial resistance surveillance in pathogenic bacteria isolated from food-producing animals. Besides, calves frequently shed potential SEPEC in their feces as commensals (“Trojan horse”). Thus, these bacteria may be disseminated in the farm environment, causing septicemia and meningitis under predisposing factors.
•Multidrug-resistant E. coli of phylogroups A and C associated with calf meningitis and septicemia.•First characterization of class 1 integrons in calf NMEC and SEPEC isolates.•Mutations in gyrA and parC determine FQ resistance in calf NMEC and SEPEC isolates.•SEPEC associated-VGs, f17 and potential SEPEC profiles are not associated with calf diarrhea.•Dairy calves are frequent fecal carriers of potential SEPEC.
Background
Hartmann's procedure (HP) is used in surgical emergencies such as colonic perforation and colonic obstruction. “Temporary” colostomy performed during HP is not always reversed in part due ...to potential morbidity and mortality associated with reversal. There are several contributing factors for patients requiring a permanent colostomy following HP. Therefore, there is still some discussion about which technique to use. The aim of this study was to evaluate perioperative variables of patients undergoing Hartmann's reversal using a laparoscopic and open approach.
Methods
The multicenter retrospective cohort study was done between January 2009 and December 2019 at 14 institutions globally. Patients who underwent Hartmann's reversal laparoscopic (LS) and open (OS) approaches were evaluated and compared. Sociodemographic, preoperative, intraoperative variables, and surgical outcomes were analyzed. The main outcomes evaluated were 30‐day mortality, length of stay, complications, and postoperative outcomes.
Results
Five hundred and two patients (264 in the LS and 238 in the OS group) were included. The most prevalent sex was male in 53.7%, the most common indication was complicated diverticular disease in 69.9%, and 85% were American Society of Anesthesiologist (ASA) II‐III. Intraoperative complications were noted in 5.3% and 3.4% in the LS and OS groups, respectively. Small bowel injuries were the most common intraoperative injury in 8.3%, with a higher incidence in the OS group compared with the LS group (12.2% vs. 4.9%, p < 0.5). Inadvertent injuries were more common in the small bowel (3%) in the LS group. A total of 17.2% in the OS versus 13.3% in the LS group required intensive care unit (ICU) admission (p = 0.2). The most frequent postoperative complication was ileus (12.6% in OS vs. 9.8% in LS group, p = 0.4)). Reintervention was required mainly in the OS group (15.5% vs. 5.3% in LS group, p < 0.5); mortality rate was 1%.
Conclusions
Laparoscopic Hartmann's reversal is safe and feasible, associated with superior clinical outcomes compared with open surgery.
