OBJECTIVE

To determine the prevalence of rectal colonization with carbapenem-resistant organisms (CRO) among PGH neonatal intensive care unit (NICU) patients.

A prospective single-center observational study conducted over a 1-month period included all NICU 3 and cohort area patients admitted on April 24, 2024. Rectal swabs were collected for multidrug-resistant organism (MDRO) screening and repeated weekly for 1 month while admitted. Swabs were inoculated on chromogenic media, and isolates were identified and tested for antimicrobial sensitivity by disk diffusion. Clinical characteristics and outcomes were collected for 30 days from initial MDRO screening. Descriptive statistics were used to summarize the data.

The point prevalence of CRO colonization was 37% (14 of 38) at initial screening. There were 14 incident colonizations, hence the 4-week period prevalence of CRO colonization was 72.5% (29 of 40). The patients were mostly very preterm, very low birth weight neonates, majority were tested within the first 2 weeks of life, and half were exposed to meropenem at initial screening. Nosocomial infection developed in 29% and 64%, and 30-day mortality rate was 8% and 21% among initially non-CRO-colonized and CRO-colonized patients respectively. Despite high CRO colonization, no culture-proven CRO infection was observed. Surveillance screening documented persistent CRO colonization in 37%, but no decolonization. Escherichia coli, Klebsiella spp. and Serratia spp. were the most common colonizers.

The high prevalence of rectal CRO colonization in the NICU emphasizes the burden of antimicrobial resistance, but despite the high CRO colonization, no CRO infection was documented from the limited sample and study period.

Leclercia adecarboxylata is a Gram-negative bacterium belonging to the Enterobacteriaceae family. To our knowledge, this is the first report of a carbapenem-resistant L. adecarboxylata strain isolated from a healthy newborn. The L. adecarboxylata strain isolated in this study carried four plasmids that may serve as reservoirs for antibiotic resistance genes. Plasmids 2 and 4 did not harbor any antimicrobial resistance genes. Plasmid 3 is a novel plasmid containing three resistance genes. The bla _IMP gene harbored in the strain was most similar to bla _IMP-79 at the nucleotide level, with a similarity of 99.4% (737/741). This case highlights the importance of considering L. adecarboxylata as a potential cause of infections in children.
Infant, Newborn ; Child ; Humans ; Female ; Enterobacteriaceae Infections/microbiology* ; Enterobacteriaceae/genetics* ; Anti-Bacterial Agents/therapeutic use* ; Plasmids

Objective: The study investigated the clinical distribution, antimicrobial resistance and epidemiologic characteristics of hypervirulent Carbapenem-resistant Klebsiella pneumoniae (hv-CRKP) in a hospital in Henan Province to provide a scientific basis for antibiotic use and nosocomial infection prevention and control. Methods: A retrospective analysis of the clinical data from the cases was carried out in this study. Clinical data of patients infected with the CRKP strain isolated from the clinical microbiology laboratory of Henan Provincial Hospital of Traditional Chinese Medicine from January 2020 to December 2022 were retrospectively analyzed. A string test, virulence gene screening, serum killing, and a G. mellonella infection model were used to screen hv-CRKP isolates. The clinical characteristics of hv-CRKP and the drug resistance rate of hv-CRKP to twenty-five antibiotics were analyzed using WHONET 5.6. Carbapenemase phenotypic characterization of the hv-CRKP was performed by colloidal gold immunochromatographic assay, and Carbapenemase genotyping, multi-locus sequence typing (MLST) and capsular serotyping of hv-CRKP isolates were performed by PCR and Sanger sequencing. Results: A total of non-duplicate 264 CRKP clinical isolates were detected in the hospital from 2020 to 2022, and 23 hv-CRKP isolates were detected, so the corresponding detection rate of hv-CRKP was 8.71% (23/264). The hv-CRKP isolates in this study were mainly from the intensive care unit (10/23) and neurosurgery department (8/23), and the main sources of hv-CRKP isolates were sputum (10/23) and bronchoalveolar lavage fluid (6/23). The hv-CRKP isolates in this study were highly resistant to β-lactam antibiotics, fluoroquinolones and aminoglycosides, and were only susceptible to colistin, tigecycline and ceftazidime/avibactam. The detection rate of the blaKPC-2 among 23 hv-CRKP isolates was 91.30% (21/23) and none of the class B and class D carbapenemases were detected. Results of MLST and capsular serotypes showed that ST11 type hv-CRKP was the dominant strain in the hospital, accounting for 56.52% (13/23), and K64 (9/13) and KL47 (4/13) were the major capsular serotypes. Conclusion: The hv-CRKP isolates from the hospital are mainly from lower respiratory tract specimens from patients admitted to the intensive care department and the drug resistance is relatively severe. The predominant strains with certain polymorphisms are mainly composed of the KPC-2-producing ST11-K64 and ST11-KL47 hv-CRKP isolates in the hospital.
Humans ; Klebsiella pneumoniae/genetics* ; Multilocus Sequence Typing ; Retrospective Studies ; Klebsiella Infections/drug therapy* ; Anti-Bacterial Agents/therapeutic use* ; Hospitals ; Carbapenem-Resistant Enterobacteriaceae/genetics* ; Microbial Sensitivity Tests ; Carbapenems/pharmacology*

Objective: The study investigated the clinical distribution, antimicrobial resistance and epidemiologic characteristics of hypervirulent Carbapenem-resistant Klebsiella pneumoniae (hv-CRKP) in a hospital in Henan Province to provide a scientific basis for antibiotic use and nosocomial infection prevention and control. Methods: A retrospective analysis of the clinical data from the cases was carried out in this study. Clinical data of patients infected with the CRKP strain isolated from the clinical microbiology laboratory of Henan Provincial Hospital of Traditional Chinese Medicine from January 2020 to December 2022 were retrospectively analyzed. A string test, virulence gene screening, serum killing, and a G. mellonella infection model were used to screen hv-CRKP isolates. The clinical characteristics of hv-CRKP and the drug resistance rate of hv-CRKP to twenty-five antibiotics were analyzed using WHONET 5.6. Carbapenemase phenotypic characterization of the hv-CRKP was performed by colloidal gold immunochromatographic assay, and Carbapenemase genotyping, multi-locus sequence typing (MLST) and capsular serotyping of hv-CRKP isolates were performed by PCR and Sanger sequencing. Results: A total of non-duplicate 264 CRKP clinical isolates were detected in the hospital from 2020 to 2022, and 23 hv-CRKP isolates were detected, so the corresponding detection rate of hv-CRKP was 8.71% (23/264). The hv-CRKP isolates in this study were mainly from the intensive care unit (10/23) and neurosurgery department (8/23), and the main sources of hv-CRKP isolates were sputum (10/23) and bronchoalveolar lavage fluid (6/23). The hv-CRKP isolates in this study were highly resistant to β-lactam antibiotics, fluoroquinolones and aminoglycosides, and were only susceptible to colistin, tigecycline and ceftazidime/avibactam. The detection rate of the blaKPC-2 among 23 hv-CRKP isolates was 91.30% (21/23) and none of the class B and class D carbapenemases were detected. Results of MLST and capsular serotypes showed that ST11 type hv-CRKP was the dominant strain in the hospital, accounting for 56.52% (13/23), and K64 (9/13) and KL47 (4/13) were the major capsular serotypes. Conclusion: The hv-CRKP isolates from the hospital are mainly from lower respiratory tract specimens from patients admitted to the intensive care department and the drug resistance is relatively severe. The predominant strains with certain polymorphisms are mainly composed of the KPC-2-producing ST11-K64 and ST11-KL47 hv-CRKP isolates in the hospital.
Humans ; Klebsiella pneumoniae/genetics* ; Multilocus Sequence Typing ; Retrospective Studies ; Klebsiella Infections/drug therapy* ; Anti-Bacterial Agents/therapeutic use* ; Hospitals ; Carbapenem-Resistant Enterobacteriaceae/genetics* ; Microbial Sensitivity Tests ; Carbapenems/pharmacology*

In this study, the effects of two plant growth-promoting bacteria Klebsiella michiganensis TS8 and Lelliottia Jeotgali MR2 on the growth and cadmium (Cd) uptake of Arabidopsis thaliana under Cd stress were explored. A wild-type Arabidopsis thaliana was selected as the experimental plant and was planted at different Cd concentrations. MR2 and TS8 bacterial suspensions were sprayed onto the rhizospheric soil during the planting process. The initial Cd concentration of the bought soil was 14.17 mg/kg, which was used as the pot soil of the low-concentration Cd treatment group (LC). The concentration of soil Cd at high-concentration Cd treatment group (HC) were 200 mg/kg higher than that at LC group. Compared with the control group, MR2 suspension significantly promoted the growth of A. thaliana at both low and high concentrations, while TS8 strain and MR2_TS8 mixture only exhibited growth-promoting effect at high concentration. However, it was noteworthy that, TS8 suspension significantly reduced the Cd content in the underground parts of A. thaliana (60% and 59%), and significantly improved the Cd content in the aboveground parts of A. thaliana (234% and 35%) at both low and high concentrations. In addition, at low concentration, both single strain and mixed strains significantly improved the transformation from reducible Cd to acid-extractable Cd in soil, promoted Cd intake, and thereby reduced the total Cd content in soil. Therefore, the rational application of plant growth-promoting bacteria may improve crop yield and remediate Cd contamination in soil.
Arabidopsis ; Bacteria ; Biodegradation, Environmental ; Cadmium/pharmacology* ; Enterobacteriaceae ; Klebsiella ; Plant Roots/chemistry* ; Soil ; Soil Pollutants

OBJECTIVES: To systematically assess the risk factors for the colonization or infection of carbapenem-resistant Enterobacteriaceae in children. METHODS: PubMed, Web of Science, China National Knowledge Infrastructure Database, Wanfang Data, China Biology Medicine disc were searched to obtain the articles on risk factors for the colonization or infection of carbapenem-resistant Enterobacteriaceae in children published up to May 31, 2021. RevMan 5.3 software was used to perform the Meta analysis. RESULTS: A total of 13 articles were included, with 1 501 samples in total. The Meta analysis showed that indwelling gastric tube (OR=4.91), tracheal intubation (OR=5.03), central venous catheterization (OR=3.75), indwelling urinary catheterization (OR=4.11), mechanical ventilation (OR=3.09), history of hospitalization in the intensive care unit (OR=2.39), history of surgical operation (OR=3.22), previous use of third-generation cephalosporins (OR=2.62), previous use of carbapenem antibiotics (OR=3.82), previous use of glycopeptide antibiotics (OR=3.48), previous use of β-lactamase inhibitors (OR=2.87), previous use of antifungal drugs (OR=2.48), previous use of aminoglycoside antibiotics (OR=2.54), and Apgar score ≤7 at 1 minute after birth (OR=2.10) were risk factors for the colonization or infection of carbapenem-resistant Enterobacteriaceae in children (P<0.05). CONCLUSIONS Invasive operations, history of hospitalization in the intensive care unit, previous use of antibiotics such as carbapenem antibiotics, and Apgar score ≤7 at 1 minute after birth are risk factors for the colonization or infection of carbapenem-resistant Enterobacteriaceae in children.
Anti-Bacterial Agents/therapeutic use* ; Carbapenem-Resistant Enterobacteriaceae ; Carbapenems/pharmacology* ; Child ; Enterobacteriaceae Infections/microbiology* ; Humans ; Risk Factors

Aims: This study evaluated in vitro resistance and susceptibility of Enterobacteriaceae (Escherichia coli and Klebsiella oxytoca strains) and Staphylococci strains, isolated from sheep’s milk, against antibiotics and essential oils from Thymus satureioides and Mentha pulegium. Methodology and results: Antibiotic resistance tests were done using disc diffusion while essential oils were extracted by steam distillation and yields were calculated relative to plant dry matter. Gas chromatography-mass spectrometry (GC-MS) was used to analyze each oil's chemical composition. Amoxicillin + Clavulanic acid (AMC), Cefotaxime (CTX), Cefoxitine (FOX), Nalidixic acid (NA), Gentamicin (CN), Ciprofloxacin (CIP) and Ofloxacin (OFX) were very effective against the E. coli strains tested. Half of the strains were resistant to AMC, 60% to Ticarcillin (TIC) and 80% to Tetracycline (TE). Klebsiella oxytoca was resistant against AMC, FOX and TIC (100%). Antibiotic-resistant testing on Staphylococci strains indicated Staphylococcus capitis and S. chromogenes as the most sensitive. Staphylococcus aureus, S. xylosus and S. cohnii ureal exhibited less resistance to Oxacilin (OX), TE, Pristinamycin (PT), Erythromycin (E) and Penicillin (P). Mentha pulegium resulted in a higher yield of essential oil of 3.2% oil compared to T. satureioides with only 1.85% yield. The monoterpene oxygenated derivatives, monoterpene hydrocarbons and phenols are found in essential oil extracts. Thymus satureioides essential oil had high antibacterial activity even at low concentrations (0.2; 0.55 g/mL). The minimal bactericidal concentration (MBC) values indicate that the essential oils from the plants analyzed had bactericidal effects on all strains tested and are similar to the minimal inhibitory concentration (MIC) values. Conclusion, significance and impact of study The high antibacterial properties of these medicinal plants, against bacteria isolated from sheep’s milk, provide an opportunity to use these medicinal plants in the breeding sector, as additives and preservatives in the dairy industry.
Enterobacteriaceae ; Staphylococcus ; Drug Resistance, Bacterial ; Sheep

The enterobacterial common antigen (ECA) is a polysaccharide composed of polysaccharide repeats that are located in the outer membrane of almost all Enterobacteriaceae bacteria and has diverse biological functions. ECA is synthesized by the synergistic action of multiple genes that are present in clusters on the genome of Enterobacteriaceae bacteria, forming the ECA antigen gene cluster, an important virulence factor that plays a role in host invasion and survival of Enterobacteriaceae in vivo. ECA also plays an important role in the maintenance of the bacterial outer membrane permeability barrier, flagella gene expression, swarming motility, and bile salts resistance. In addition, ECALPS, anchored in the core region of bacterial lipopolysaccharide, is an important surface antigen for bacteria, stimulating high levels of antibody production in the host and could be a target for vaccine research. This review summarizes ECA purification, genes involved in ECA biosynthesis, its immunological characteristics, biological functions and clinical applications.
Antigens, Bacterial/genetics* ; Enterobacteriaceae/genetics* ; Lipopolysaccharides ; Polysaccharides

Antibiotic resistance is a major global concern and challenge in the 21st century. Enterobacteriaceae are one of the important pathogens of hospital-acquired infections. With the increasing use of antibiotics in clinical practice, a variety of drug-resistant Enterobacteriaceae, especially multidrug-resistant Enterobacteriaceae have emerged, posing an increasingly serious threat to human health. Bacteria can acquire antibiotic resistance by mutation or horizontal transfer of antibiotic resistance genes, and it is often possible to predict the corresponding resistance phenotype from known mechanism. However, recent findings suggest that genetic background and environmental factors could alter the expression of specific resistance genes and that a given genotype does not always generate the expected resistance phenotype. The genotype-phenotype segregation greatly hampers our ability to predict antibiotic resistance phenotype from a genetic perspective. In this review, we explore the genetic and environmental regulation of the expression of antibiotic resistance genes in a variety of Enterobacteriaceae, with the aim to provide scientific evidence for genetic prediction of antibiotic resistance phenotype and clinical guidance on drug use.
Anti-Bacterial Agents/pharmacology* ; Bacteria ; Cross Infection ; Drug Resistance, Microbial ; Enterobacteriaceae/genetics* ; Humans

Aims: Food safety and drug resistance in bacteria are both important issues globally. Consumption of escargot represents possible food safety problem especially when contaminated with an indicator and multi-drug resistant bacteria. Hence, this study aimed to identify and evaluate susceptibility of Enterobacteriaceae isolated from edible snails Archachatina marginata to antibiotics. Methodology and results: A total of 60 edible snails, A. marginata were purchased from local markets in three states of Nigeria. The edible snails were starved for three days and Enterobacteriaceae were isolated using microbiological procedures. Bacteria was identified by sequencing its partial 16S rRNA, while susceptibility of the bacteria to antibiotic was determined by disc diffusion method. Enterobacteriaceae obtained were Klebsiella (18), Escherichia (16), Citrobacter (10), Salmonella (7) and Enterobacter (5) species. Out of the 56 isolates obtained, 21 (37.5%) were resistant to amoxicillin and amoxicillin/clavulanic acid, 9 (16.07%) were resistant to tetracycline and 4 (7.14%) were resistant to co-trimoxazole. Conclusion, significance and impact of study The number of isolates which show resistant to different antibiotic classes was small. However, coliform bacteria (Escherichia coli, Klebsiella pneumoniae, Citrobacter freundii, and Enterobacter cloacae) isolated from edible snails represent a huge food safety risk to the consumers of edible snails. Hence, high hygienic practices are required for the consumers of edible snails to prevent infection with pathogenic bacteria.
Enterobacteriaceae--isolation & ; purification ; Snails