Intestinal Carriage Research Articles

Epidemiology of extended-spectrum β-lactamase-producing Enterobacteriaceae among healthcare students, at the Portuguese Red Cross Health School of Lisbon, Portugal

ObjectiveThe aim of the present study was to prospectively evaluate the prevalence of intestinal carriage by extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae among Portuguese students attending a Bachelors’ course in healthcare, and to determine the molecular features of ESBL-producing isolates. MethodsOne-hundred and eleven faecal samples recovered from Portuguese healthcare students were screened for either ESBL-producing, carbapenem-resistant, colistin-resistant or pan-aminoglycoside-resistant Enterobacteriaceae, using respective screening media. All recovered isolates were tested for antimicrobial susceptibility and characterised by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). ResultsA total of 17 ESBL-producing Enterobacteriaceae (16 Escherichia coli and a single Klebsiella pneumoniae) were recovered from 16 students, representing a prevalence of 14.5%. The E. coli isolates were distributed into three sequence types (STs) and seven PFGE types. The most common ESBL identified was CTX-M-1 (n=13; 76%), followed by CTX-M-15 (n=3; 18%) and CTX-M-8 (n=1; 6%). The majority of the strains were resistant to sulfonamides (88%) and fosfomycin (71%). Resistance to aminoglycosides was observed at a low rate, that is 12% for both tobramycin and kanamycin. No colistin-, carbapenem- or pan-aminoglycoside-resistant isolates were recovered. A major clone, ST10-blaCTX-M-1, included 12 E. coli isolates. The blaCTX-M-1 gene was always located on an IncFIA/FIB plasmid type, co-harbouring genes encoding resistance to tetracycline, sulfonamides, trimethoprim–sulfamethoxazole and fosfomycin. ConclusionThe most commonly identified ESBL gene in E. coli was blaCTX-M-1, usually identified among ESBL-producing isolates recovered from animals. A high prevalence of faecal carriage of ESBL-producing E. coli was found among healthy healthcare students, underlying this population as an important reservoir.

Investigating the use of bacteriophages as a new decolonization strategy for intestinal carriage of CTX-M-15-producing ST131 Escherichia coli: An in vitro continuous culture system model

ObjectivesWe investigated the use of bacteriophages as a strategy to decolonize intestinal carriers of multidrug-resistant Escherichia coli. MethodsA fermentor was used as a continuous culture system for 48h. Two different pools of faeces (studies I and II) obtained from volunteers were spiked with a CTX-M-15-producing ST131 E. coli (strain 4901.28) susceptible to bacteriophages and challenged with three doses of INTESTI Bacteriophage cocktail administered at 2, 6 and 10h after the inoculum. Bacterial typing was performed by implementing microdilution panels, spot test, rep-PCR and whole-genome sequencing (including cgMLST and single-nucleotide variant analysis) obtained using Nanopore and Illumina platforms. ResultsIn study I, bacteriophages decreased the numbers of 4901.28 dramatically (≤101CFU/mL after 6h). In contrast, during study II, a phage-resistant mutant of 4901.28 persisted in the continuous culture (104CFU/mL at 48h). Whole-genome sequencing revealed the presence of two additional plasmids in the mutant as well as 11 single-nucleotide variants, including one chromosomal in a glycosyltransferase family 2 protein that is responsible for the transfer of sugars to polysaccharides and lipids. In both studies, the commensal E. coli population remained unchanged by the phage treatment maintaining itself at 108CFU/mL. ConclusionsOur data indicates that bacteriophage cocktails may be implemented to decolonize some intestinal carriers. However, the individual microbiota composition may have an impact on the development of phage resistance. Mechanisms underlying this phenomenon are likely to be various and complex. Further in vivo studies and protein expression experiments are needed to confirm our observations and hypotheses.

Fecal carriage and molecular epidemiologic characteristics of carbapenemase-producing Enterobacterales in primary care hospital in a Japanese city

BackgroundThe worldwide spread of organisms with antimicrobial resistance is of concern, especially the trend of significantly increasing carbapenemase-producing Enterobacterales (CPE). In this study, we investigated the annual trend of intestinal CPE carriage rates in inpatients and healthy adults in a primary care hospital in Tenri, Japan. MethodsWe collected 551 samples of feces from inpatients in our institution and 936 samples from healthy people living in Tenri city from December 2012 to April 2015. All samples were cultured on MacConkey agar plates containing 4 μg/mL ceftazidime for screening test. The colonies grown on the screening medium were detected for carbapenemase genes (blaIMP-1, blaIMP-2, blaVIM, blaKPC, blaGES, blaNDM, and blaOXA-48 groups) by multiplex PCR, and CPE were identified by MALDI-TOF MS. Plasmid replicon typing and pulsed-field gel electrophoresis (PFGE) were performed on PCR-positive strains. ResultsThe CPE carriage rate was 1.6% (9/551) in the inpatient group and 0% (0/936) in the healthy adults group. The numbers of strains positive for the carbapenemase gene were 4 for Enterobacter cloacae, 2 for Klebsiella pneumoniae, 1 for Citrobacter freundii, 1 for Raoultella ornithinolytica and 1 for Escherichia coli. In all CPE strains, the carbapenemase gene was blaIMP-6 and the plasmid replicon type was IncN. The 4 E. cloacae strains showed a similar pattern in PFGE. ConclusionIn the same city in Japan, CPE intestinal carriers were detected only in the inpatient group in this study but not in a healthy adults, suggesting that the spread of asymptomatic CPE carriers was confined to inpatients.

Klebsiella pneumoniae carriage in low-income countries: antimicrobial resistance, genomic diversity and risk factors

ABSTRACT Background: Klebsiella pneumoniae (hereafter, Kp) is a major public health threat responsible for high levels of multidrug resistant (MDR) human infections. Besides, Kp also causes severe infections in the community, especially in Asia and Africa. Although most Kp infections are caused by endogenous intestinal carriage, little is known about the prevalence and microbiological characteristics of Kp in asymptomatic human carriage, and attached risk factors including environmental sources exposure. Methods: Here, 911 pregnant women from communities in Madagascar, Cambodia, and Senegal were screened for gut colonization by Kp. Characteristics of Kp strains (antimicrobial susceptibility, genomic diversity, virulence, and resistance genes) were defined, and associated risk factors were investigated. Results: Kp carriage rate was 55.9%, and Kp populations were highly heterogeneous (6 phylogroups, 325 sequence types, Simpson index 99.6%). One third of Kp isolates had acquired antimicrobial resistance genes. MDR-Kp (11.7% to 39.7%) and extended spectrum beta-lactamase (ESBL)-producing Kp (0.7% to 14.7%) varied among countries. Isolates with virulence genes were detected (14.5%). Environmental exposure factors including food, animal contacts, or hospitalization of household members were associated with carriage of Kp, antimicrobial resistance and hypervirulence. However, risk factors were country-specific and Kp subpopulation-specific. Conclusion: This large-scale multicenter study uncovers the huge diversity of Kp in human gut carriage, demonstrates that antimicrobial resistance is widespread in communities of three low-income countries, and underlines the challenges posed by Kp colonization to the control of antimicrobial resistance.

Screening methods for intestinal carriage of multidrug-resistant Enterobacterales: interest of enrichment broth

Travel abroad is associated with a high risk of acquiring multidrug-resistant Enterobacterales (MDR-E) [i.e., extended-spectrum beta-lactamase–producing Enterobacterales (ESBL-E) and plasmid-mediated-AmpC beta-lactamase–producing Enterobacterales (pAmpC-E)]. Here, we evaluated the utility of pre-enrichment and performance of screening for MDR-E using 2 different media (ChromID-ESBL and biplate-ESBL) from 574 traveler stool samples. ESBL-E and MDR-E were detected in 49% (281/574) and 51% (296/574) of travelers, respectively. Pre-enrichment improved the detection of ESBL-E and MDR-E by 11.7% and 12.5%, respectively, without decreasing specificity (88.4% versus 87.4% for ESBL-E screening and 92.4% versus 89.9% for MDR-E screening). Sensitivity of the biplate-ESBL agar was higher than for ChromID-ESBL for ESBL-E detection (92.9% versus 86.1%), but specificity was lower (64.2% versus 87.4%). Whereas pAmpC-E were all detected by biplate-ESBL, 96% (47/49) and 82% (40/49) were detected by ChromID-ESBL, respectively, with and without pre-enrichment. Pre-enrichment increases the performance of MDR-E screening, especially in individuals with low MDR-E digestive abundance.

Whole genome analysis of multidrug-resistant Citrobacter freundii B9-C2 isolated from preterm neonate’s stool in the first week

BackgroundResistance to colistin, the last line therapy for infections caused by multidrug-resistant Gram-negative bacteria, represents a major public health threat. Citrobacter freundii B9-C2 which was isolated from the stool of preterm neonate on the first week of life, displayed resistance to almost all major antibiotics, including colistin. Through whole genome sequencing (WGS), we characterised the genome features that underline the antibiotic-resistance phenotype of this isolate. MethodsGenome of C. freundii B9-C2 was sequenced on an Illumina MiSeq platform. The assembled genome was annotated and deposited into GenBank under the accession number CP027849. ResultsMultiple antimicrobial resistance genes including blaCMY-66 were identified. Further, the presence of 15 antibiotic efflux pump-encoding resistance genes, including crp, baeR, hns, patA, emrB, msbA, acrA, acrB, emrR, mdtC, mdtB, mdtG, kdpE, mdfA and msrB, were detected and likely to account for the observed cephalosporins, carbapenems, aminoglycosides and monobactams resistance in C. freundii B9-C2. The isolate also presented unique virulence genes related to biofilm formation, motility and iron uptake. The genome was compared to publicly available genomes and it was closely related to strains with environmental origins. ConclusionTo the best of our knowledge, this is the first report of intestinal carriage of colistin-resistant C. freundii from the stool of a neonate in Malaysia. Using genomic analysis, we have contributed to the understanding of the potential mechanism of resistance and the phylogenetic relationship of the isolates with draft genomes available in the public domain.

Proof-of-concept trial of the combination of lactitol with Bifidobacterium bifidum and Lactobacillus acidophilus for the eradication of intestinal OXA-48-producing Enterobacteriaceae

BackgroundThe major reservoir of carbapenemase-producing Enterobacteriaceae (CPE) is the gastrointestinal tract of colonized patients. Colonization is silent and may last for months, but the risk of infection by CPE in colonized patients is significant.MethodsEight long-term intestinal carriers of OXA-48-producing Enterobacteriaceae (OXA-PE) were treated during 3 weeks with daily oral lactitol (Emportal®), Bifidobacterium bifidum and Lactobacillus acidophilus (Infloran®). Weekly stool samples were collected during the treatment period and 6 weeks later. The presence of OXA-PE was investigated by microbiological cultures and qPCR.ResultsAt the end of treatment (EoT, secondary endpoint 1), four of the subjects had negative OXA-PE cultures. Three weeks later (secondary endpoint 2), six subjects were negative. Six weeks after the EoT (primary endpoint), three subjects had negative OXA-PE cultures. The relative intestinal load of OXA-PE decreased in all the patients during treatment.ConclusionsThe combination of prebiotics and probiotics was well tolerated. A rapid reduction on the OXA-PE intestinal loads was observed. At the EoT, decolonization was achieved in three patients.Clinical Trials Registration: NCT02307383. EudraCT Number: 2014-000449-65.

The Colonization of Carbapenem-Resistant Klebsiella pneumoniae: Epidemiology, Resistance Mechanisms, and Risk Factors in Patients Admitted to Intensive Care Units in China.

Carbapenem-resistant Klebsiella pneumoniae (CRKP) has become a threat to public health, most notably as a superbug causing nosocomial infections. Patients in the intensive care unit (ICU) are at increased risk of hospital-acquired K pneumoniae infection, especially CRKP. This study was conducted to investigate the frequency of gastrointestinal and nasopharyngeal K pneumoniae colonization and its contribution to infections in ICU patients. A 3-month prospective cohort study was performed in which 243 ICU patients were screened for intestinal and nasopharyngeal carriage of K pneumoniae at admission and once per week thereafter. The colonization and clinical infection isolates were analyzed by antimicrobial susceptibility testing to identify CRKP and were characterized by multilocus sequence typing (MLST) and whole-genome sequencing combined with epidemiological data to investigate the resistance mechanisms and assess the possible transmitted infection. Twenty-eight percent (68 of 243) of patients tested positive for carriage of K pneumoniae immediately upon admission to ICU, 54% (37 of 68) of which were nonduplicate CRKP isolates. Patients with carbapenem-susceptible K pneumoniae (CSKP) colonization at admission were more likely to acquire CRKP colonization during the ICU stay compared with patients without K pneumoniae colonization at admission. The incidence of subsequent CRKP infection in the baseline CSKP (32.3%, 10 of 31) and CRKP (45.9%, 17 of 37) carrier group was significantly higher than that of the baseline non-KP carrier group (8.6%, 15 of 175). The risk factors associated with acquired CRKP colonization during the ICU stay among negative CRKP colonization at admission included previous exposure to carbapenem, tigecycline or β-lactam/β-lactamases inhibitor, and invasive processes or surgical operations. Sixty-four percent (27 of 42) of patients with K pneumoniae infection were colonized by clonally related K pneumoniae strains according to enterobacterial repetitive intergenic consensus sequence-polymerase chain reaction analysis. ST11 (72%, 53 of 74) was the most predominant MLST type of clonally related CRKP isolate colonizing these patients, followed by ST15 (26%, 19 of 74). The colonization of K pneumoniae may increase the incidence of corresponding K pneumoniae infection in critically ill patients in the ICU. High prevalence of ST11 CRKP (due to blaKPC-2) carriage and infection in ICU was observed.

Integrative analysis of gut microbiome and metabolites revealed novel mechanisms of intestinal Salmonella carriage in chicken

Intestinal carriage of Salmonella Enteritidis (SE) in the chicken host serves as a reservoir for transmission of Salmonella to humans through the consumption of poultry products. The aim of the current study was to examine the three-way interaction that occurred between host metabolites, resident gut microbiota and Salmonella following inoculation of SE in two-week-old layer chicks. Our results revealed an overall alteration in gut microbiome and metabolites in association with SE infection. Enriched colonization by different microbial members throughout the course of experimental infection highlighted significant fluctuation in the intestinal microbial community in response to Salmonella infection. As changes in community membership occurred, there was also subsequent impact on differential regulation of interlinked predicted functional activities within the intestinal environment dictated by Salmonella-commensal interaction. Alteration in the overall microbial community following infection also has a ripple effect on the host regulation of cecum-associated metabolic networks. The findings showed that there was differential regulation in many of the metabolites in association with SE colonization in chickens. Perturbation in metabolic pathways related to arginine and proline metabolism as well as TCA cycle was most prominently detected. Taken together, the present findings provided a starting point in understanding the effect of intestinal Salmonella carriage on the microbiome and metabolome of developing young layer chicks.

Protocol for a randomised trial of early kangaroo mother care compared to standard care on survival of pre-stabilised preterm neonates in The Gambia (eKMC)

BackgroundComplications of preterm birth cause more than 1 million deaths each year, mostly within the first day after birth (47%) and before full post-natal stabilisation. Kangaroo mother care (KMC), provided as continuous skin-to-skin contact for 18 h per day to fully stabilised neonates ≤ 2000 g, reduces mortality by 36–51% at discharge or term-corrected age compared with incubator care. The mortality effect of starting continuous KMC before stabilisation is a priority evidence gap, which we aim to investigate in the eKMC trial, with a secondary aim of understanding mechanisms, particularly for infection prevention.MethodsWe will conduct a single-site, non-blinded, individually randomised, controlled trial comparing two parallel groups to either early (within 24 h of admission) continuous KMC or standard care on incubator or radiant heater with KMC when clinically stable at > 24 h of admission. Eligible neonates (n = 392) are hospitalised singletons or twins < 2000 g and 1–24 h old at screening who are mild to moderately unstable as per a trial definition using cardio-respiratory parameters. Randomisation is stratified by weight category (< 1200 g; ≥ 1200 g) and in random permuted blocks of varying sizes with allocation of twins to the same arm. Participants are followed up to 28 ± 5 days of age with regular inpatient assessments plus criteria-led review in the event of clinical deterioration. The primary outcome is all-cause neonatal mortality by age 28 days. Secondary outcomes include the time to death, cardio-respiratory stability, hypothermia, exclusive breastfeeding at discharge, weight gain at age 28 days, clinically suspected infection (age 3 to 28 days), intestinal carriage of extended-spectrum beta-lactamase producing (ESBL) Klebsiella pneumoniae (age 28 days), and duration of the hospital stay. Intention-to-treat analysis will be applied for all outcomes, adjusting for twin gestation.DiscussionThis is one of the first clinical trials to examine the KMC mortality effect in a pre-stabilised preterm population. Our findings will contribute to the global evidence base in addition to providing insights into the infection prevention mechanisms and safety of using this established intervention for the most vulnerable neonatal population.Trial registrationClinicalTrials.gov NCT03555981. Submitted 8 May 2018 and registered 14 June 2018. Prospectively registered.

Unexpected differences in the pharmacokinetics of N-acetyl-DL-leucine enantiomers after oral dosing and their clinical relevance.

The enantiomers of many chiral drugs not only exhibit different pharmacological effects in regard to targets that dictate therapeutic and toxic effects, but are also handled differently in the body due to pharmacokinetic effects. We investigated the pharmacokinetics of the enantiomers of N-acetyl-leucine after administration of the racemate (N-acetyl-DL-leucine) or purified, pharmacologically active L-enantiomer (N-acetyl-L-leucine). The results suggest that during chronic administration of the racemate, the D-enantiomer would accumulate, which could have negative effects. Compounds were administered orally to mice. Plasma and tissue samples were collected at predetermined time points (0.25 to 8 h), quantified with liquid chromatography/mass spectrometry, and pharmacokinetic constants were calculated using a noncompartmental model. When administered as the racemate, both the maximum plasma concentration (Cmax) and the area under the plasma drug concentration over time curve (AUC) were much greater for the D-enantiomer relative to the L-enantiomer. When administered as the L-enantiomer, the dose proportionality was greater than unity compared to the racemate, suggesting saturable processes affecting uptake and/or metabolism. Elimination (ke and T1/2) was similar for both enantiomers. These results are most readily explained by inhibition of uptake at an intestinal carrier of the L-enantiomer by the D-enantiomer, and by first-pass metabolism of the L-, but not D-enantiomer, likely by deacetylation. In brain and muscle, N-acetyl-L-leucine levels were lower than N-acetyl-D-leucine, consistent with rapid conversion into L-leucine and utilization by normal leucine metabolism. In summary, the enantiomers of N-acetyl-leucine exhibit large, unexpected differences in pharmacokinetics due to both unique handling and/or inhibition of uptake and metabolism of the L-enantiomer by the D-enantiomer. Taken together, these results have clinical implications supporting the use of N-acetyl-L-leucine instead of the racemate or N-acetyl-D-leucine, and support the research and development of only N-acetyl-L-leucine.

Evaluation of the Association Between Gastric Acid Suppression and Risk of Intestinal Colonization With Multidrug-Resistant Microorganisms

Acid suppressants inhibit gastric acid secretion and disrupt the intestinal microbiome. Whether acid suppression increases the risk of colonization with multidrug-resistant microorganisms (MDROs) is unclear. To systematically examine the association of use of acid suppressants with the risk of colonization with MDROs and to perform a meta-analysis of current evidence. PubMed, Embase, the Web of Science Core Collection, and the Cochrane Central Register of Controlled Trials were searched from database inception through July 8, 2019. Study selection was performed independently by 2 authors (R.P.J.W. and C.M.J.E.V.-G.) on the basis of predefined selection criteria; conflicts were resolved by consensus or by an adjudicator (K.v.D.). Human observational studies (case control, cohort, and cross-sectional) and clinical trial designs were selected if they quantified the risk of MDRO colonization in users of acid suppressants in comparison with nonusers. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) and Meta-analysis of Observational Studies in Epidemiology (MOOSE) recommendations were followed. Data were extracted independently by the same 2 authors, and adjudication was conducted when necessary. Risk of bias was assessed according to a modified Newcastle-Ottawa Scale. Pooled odds ratios (ORs) were estimated using random-effects models; heterogeneity was evaluated using the I2 method. The primary outcome measure was intestinal colonization with MDROs of the Enterobacterales order (producing extended-spectrum β-lactamases, carbapenemases, or plasmid-mediated AmpC β-lactamases), vancomycin-resistant enterococci, methicillin-resistant or vancomycin-resistant Staphylococcus aureus, or multidrug-resistant Pseudomonas or Acinetobacter species. A total of 26 observational studies including 29 382 patients (11 439 [38.9%] acid suppressant users) met the selection criteria. Primary meta-analysis of 12 studies including 22 305 patients that provided adjusted ORs showed that acid suppression increased the odds of intestinal carriage of MDROs of the Enterobacterales order and of vancomycin-resistant enterococci by roughly 75% (OR = 1.74; 95% CI, 1.40-2.16; I2 = 68%). The odds were concordant with the secondary pooled analysis of all 26 studies (OR = 1.70; 95% CI, 1.44-1.99; I2 = 54%). Heterogeneity was partially explained by variations in study setting and the type of acid suppression. Acid suppression is associated with increased odds of MDRO colonization. Notwithstanding the limitations of observational studies, the association is plausible and is strengthened by controlling for confounders. In view of the global increase in antimicrobial resistance, stewardship to reduce unnecessary use of acid suppressants may help to prevent MDRO colonization.

Non-typhoidal Salmonella intestinal carriage in a Schistosoma mansoni endemic community in a rural area of the Democratic Republic of Congo.

BackgroundClinical observations and animal studies have suggested that Salmonella intestinal carriage is promoted by concurrent Schistosoma infection. The present study assessed association of Salmonella intestinal carriage and Schistosoma mansoni infection among individuals in a Schistosoma endemic area in sub-Saharan Africa.MethodsFrom November 2015 to March 2016, a cross-sectional community-wide study was conducted in Kifua II, a rural village in Kongo Central Province, Democratic Republic of Congo. Stool samples were collected and analyzed for Salmonella intestinal carriage (culture) and Schistosoma mansoni infection (Kato Katz microscopy with determination of egg load). Salmonella Typhimurium and Enteritidis isolates were assessed for genetic similarity with blood culture isolates obtained during the same period in a neighboring hospital using multi-locus variable-numbers tandem repeat analysis (MLVA).ResultsA total of 1,108 participants were included (median age 15 years (IQR: 7–36), male-to-female ratio of 1:1.1). The overall prevalence of Schistosoma mansoni infection and non-typhoidal Salmonella carriage was 51.2% (95% CI: 48.2–54.1) and 3.4% (95% CI: 2.5–4.7) respectively, with 2.2% (95% CI: 1.5–3.2) of participants coinfected. The proportion of Salmonella carriage tended to be higher among Schistosoma mansoni infected participants compared to non-infected participants but this difference did not reach statistical significance (4.2% versus 2.6%, p = 0.132). However, the proportion of Salmonella carriage among participants with a heavy Schistosoma mansoni infection was significantly higher compared to those with a light and moderate infection (8.7% versus 3.2%, p = 0.012) and compared to Schistosoma mansoni negatives (8.7% versus 2.6%, p = 0.002). The 38 Salmonella isolates comprised five and four Enteritidis and Typhimurium serotypes respectively, the majority of them had MLVA types identical or similar to those observed among blood culture isolates.ConclusionSalmonella intestinal carriage was associated with a heavy intensity of Schistosoma mansoni infection. Further studies are needed to address causation.

Prolonged outbreak of New Delhi metallo-beta-lactamase-producing carbapenem-resistant Enterobacterales (NDM-CRE), Tuscany, Italy, 2018 to 2019.

In Tuscany, Italy, New Delhi metallo-beta-lactamase-producing carbapenem-resistant Enterobacterales (NDM-CRE) have increased since November 2018. Between November 2018 and October 2019, 1,645 samples were NDM-CRE-positive: 1,270 (77.2%) cases of intestinal carriage, 129 (7.8%) bloodstream infections and 246 (14.9%) infections/colonisations at other sites. Klebsiella pneumoniae were prevalent (1,495; 90.9%), with ST147/NDM-1 the dominant clone. Delayed outbreak identification and response resulted in sustained NDM-CRE transmission in the North-West area of Tuscany, but successfully contained spread within the region.

Infections due to carbapenemase-producing bacteria, clinical burden, and impact of screening strategies on outcome

ObjectivesTo characterize the risk factors, impact of screening, and clinical burden of colonization and/or infection by carbapenemase-producing bacteria (CPB) in hospitalized patients. MethodRetrospective study in a tertiary care hospital between 2008 and 2016. ResultsAmong 88 included patients, 41% were colonized, 59% developed an infection, and 69% of all cases were hospital-acquired. Risk factors for CPB contamination included recent invasive medical device (94% of patients), antibiotic therapy (82%), travel abroad (17%), and hospitalization (>50%) with 80% of all patients with underlying chronic condition. Intestinal carriage represented 89% of all colonization cases and 50% of infections were located in the urinary tract. The recent use of mechanical ventilation devices was significantly more observed in infected patients than colonized patients. The most frequent CPB was Klebsiella pneumoniae and the most frequent carbapenemase was OXA-48. Overall mortality rate was 19%. Prevalence of CPB detection in intensive care units (ICU) based on systematical rectal screen swab upon admission remained <0.5%. The infected/colonized ratio (CPB colonization cases evolving into an infection) was 23%. The time between CPB infection diagnosis and start of appropriate antimicrobial therapy increased from 1 day in previously screened patients with positive CPB to 4 days in patients with previous negative or absent screening. ConclusionOur results emphasize the importance of CPB screening in all ICU patients and in at-risk patients hospitalized in other units, to allow earlier adequate antibiotic therapy in case of infection which occurred in 23% of the colonized patients.

Intestinal carriage of colistin resistant Enterobacteriaceae in hospitalized patients from an Indian center

There is limited data on the gut colonization rate of colistin resistant (Col-R) bacteria in patients and healthy volunteers in India. Aim of this study was to investigate the stool carriage rate of Col-R in hospitalized patients. Stool samples were inoculated in Eosin Methylene Blue agar plates supplemented with colistin. Colistin minimum inhibitory concentrations (MICs) were determined by the broth microdilution method. PCR for the mcr-1 was performed on Col-R Enterobacteriaceae isolates. Mutations in the mgrB gene were analyzed in K. pneumoniae isolates. Mcr-1 positive E. coli was subjected to whole-genome sequencing. Out of 65 stool samples screened, 33 (51%) samples carried Col-R bacteria. Majority (76.7%) of the isolates were sensitive to carbapenem.

A Case Study on Wild Birds: A Human Enteric Pathogens Transmission

Wild birds have been shown to be vectors for enteric pathogens, they may constitute an environmental carrier of pathogens representing a source of human infection. The study aims to evaluate the intestinal carriage of Salmonella spp, Campylobacter spp and Yersinia enterocolitica in wild birds in the Italian Regional Natural Park of “Lagolungo and Ripasottile” lakes. A total of 276 samples from 16 bird species were sampled and tested by classical cultural methods and the presence of Salmonella and Y. enterocolitica was detected, using real time PCR as screening methods. None of the fecal samples were positive for Y. enterocolitica. Campylobacter spp was isolated from 4 fecal specimens and Salmonella positive results were obtained from three avian species. Four different colonies of S. Napoli isolated from Cettia cetti were submitted to molecular typing by PFGE, all showing the same genetic pattern and sharing 70-80% homology with the 3 representative human isolates. One strain of S. Typhimurium from Nycticorax nyctcorax and one strain of S. Livingstone from Sylvia atricapilla were also isolated. Campylobacter spp. were isolated from Phylloscopus collybita, Cyanistes caeruleus, Prunella modularis, Carduelis chloris chloris. Wild birds, might cause the contamination of vegetables crops either directly with faecal material, or indirectly, with pollution of irrigation water. The study demonstrated that the molecular platforms to detect Salmonella and Y. enterocolitica seem to be very appealing as screening methods. Enteric pathogen circulation associated to wild fauna strictly linked to water ecosystems open new scenarios of management agricultural practices.

Intestinal carriage of extended-spectrum beta-lactamase-producing Enterobacteriaceae at admission in a Portuguese hospital.

To evaluate the prevalence of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae fecal carriers at admission in a Portuguese hospital and to determine the epidemiology and antimicrobial resistance patterns of ESBL-producing isolates. During a 2-month period, rectal swabs were collected at hospital admission from 151 at-risk patients. In addition, 48 rectal swabs were obtained from weekly screenings of 37 patients hospitalized for > 48h. All ESBL/carbapenemase-producing isolates were tested for antimicrobial susceptibility and characterized by PFGE and MLST. The prevalence of ESBL producers at hospital admission was 17% and 24% among at-risk patients hospitalized for > 48h, while the prevalence of carbapenemase producers was 3% in both cases. Most of the isolates were Escherichia coli (54%) and Klebsiella pneumoniae (41%). The most common ESBL identified was CTX-M-15 (n = 17/34; 50%), followed by CTX-M-27 (n = 10; 29%), CTX-M-33 (n = 4; 12%), SHV-12 (n = 2), and CTX-M-55 (n = 1). The 20 E. coli isolates were distributed into 16 PFGE types and nine sequence types (ST), with 60% of the isolates belonging to ST131. The 15 K. pneumoniae were grouped into 12 PFGE types and nine STs, with three STs (ST17, ST449, ST147) corresponding to 60% of the isolates. A high proportion of isolates showed resistance to ciprofloxacin (86%), trimethoprim-sulfamethoxazole (68%), tobramycin (57%), and gentamicin (43%). All isolates remained susceptible to fosfomycin. A high prevalence of ESBL-producing Enterobacteriaceae was found at hospital admission among at-risk patients and > 50% of the isolates showed resistance to first-line antibiotics for the treatment of lower urinary tract infections, leaving fosfomycin as an alternative.

Synthesis and in vitro evaluation of cyclodextrin hyaluronic acid conjugates as a new candidate for intestinal drug carrier for steroid hormones

Steroid hormones became increasingly interesting as active pharmaceutical ingredients for the treatment of endocrine disorders. However, medical applications of many steroidal drugs are inhibited by their very low aqueous solubilities giving rise to low bioavailabilities. Therefore, the prioritized oral administration of steroidal drugs remains problematic. Cyclodextrins are promising candidates for the development of drug delivery systems for oral route applications, since they solubilize hydrophobic steroids and increase their rate of transport in aqueous environments. In this study, the synthesis and characterization of polymeric β-cyclodextrin derivates is described, which result from the attachment of a hydrophilic β-CD-thioether to hyaluronic acid. Host-guest complexes of the synthesized β-cyclodextrin hyaluronic acid conjugates were formed with two poorly soluble model steroids (β-estradiol, dexamethasone) and compared to monomeric β-cyclodextrin derivates regarding solubilization and complexation efficiency. The β-cyclodextrin-drug (host-guest) complexes were evaluated in vitro for their suitability (cytotoxicity and transport rate) as intestinal drug carriers for steroid hormones. In case of β-estradiol, higher solubilities could be achieved by complexation with both synthesized β-cyclodextrin derivates, leading to significantly higher intestinal transport rates in vitro. However, this success could not be shown for dexamethasone, which namely solubilized better, but could not enhance the transport rate significantly. Thus, this study demonstrates the biocompatibility of the synthesized and characterized β-cyclodextrin derivates and shows their potential as new candidate for intestinal drug carrier for steroid hormones like β-estradiol.

Intestinal carriage of colistin-resistant Enterobacteriaceae at Saint Georges Hospital in Lebanon

ObjectivesThe increase in resistance to antibiotics has led to the revival of colistin as the last option for treatment, which automatically led to an increase of colistin-resistant, Gram-negative bacteria. In this study, we report the presence of clinical colistin-resistant Enterobacteriaceae isolated from a Lebanese hospital. MethodsFrom 23 rectal swabs, eight colistin-resistant clinical strains (five Escherichia coli, two Enterobacter cloacae, and one Klebsiella pneumoniae) were isolated. Antibiotic susceptibility testing was performed using the disk diffusion method and Etest. The broth microdilution method was used to determine colistin susceptibility. Reverse transcription polymerase chain reaction (RT-PCR), standard PCR and sequencing were used to investigate genes encoding for extended-spectrum β-lactamases, carbapenemases and colistin resistance. Genotyping of these isolates was conducted by multilocus sequence typing (MLST). ResultsResults of antibiotic susceptibility testing revealed that all isolates were resistant to colistin. They had MICs for colistin that ranged from 8 to 32 mg/L. Real-time PCR results showed that five strains harboured blaTEM-1 and one strain harboured blaTEM-163. Moreover, four strains were positive for blaCTX-M-15, blaCTX-M-103 and blaCTX-M-189, and K. pneumoniae harboured blaSHV-1. Observed colistin resistance was linked to amino acid substitutions into protein sequences of pmrA/B, phoP/Q, and mgrB. Interestingly, we report here a mutation in the mgrB regulator and pmrA/B, phoP/Q in colistin-resistant E. cloacae and E. coli clinical isolates for the first time in Lebanon. ConclusionThis study highlights the presence of colistin-resistant Gram-negative bacteria in a Lebanese hospital, which is worrisome. An urgent strategy needs to be adopted to avoid the spread of such bacteria.