Leclercia adecarboxylata: a case report and literature review of 74 cases demonstrating its pathogenicity in immunocompromised patients

Resistance phenotype and virulence potential of Leclercia adecarboxylata strains isolated from different sources

Introduction. Leclercia adecarboxylata is a member of Enterobacterales, often considered an opportunistic pathogen. Recent reports have highlighted L. adecarboxylata as an emerging pathogen harbouring virulence and resistance determinants.Gap statement. Little information exists on virulence and resistance determinants in L. adecarboxylata strains isolated from environmental, food, and clinical samples.Aim. To determine the presence of resistance and virulence determinants and plasmid features in L. adecarboxylata strains isolated from environmental, food, and clinical samples, as well as their phylogenetic relationship.Results. All strains tested showed resistance to β-lactams and quinolones but were sensitive to aminoglycosides and nitrofurans. However, even though fosfomycin resistance is considered a characteristic trait of L. adecarboxylata, the resistance phenotype was only observed in 50 % of the strains; bla TEM was the most prevalent BLEE gene (70 %), while the quinolone qnrB gene was observed in 60 % of the strains. Virulence genes were differentially observed in the strains, with adhesion-related genes being the most abundant, followed by toxin genes. Finally, all strains carried one to seven plasmid bands ranging from 7 to 125 kbps and harboured several plasmid addiction systems, such as ParDE, VagCD, and CcdAB in 80 % of the strains.Conclusions. L. adecarboxylata is an important emerging pathogen that may harbour resistance and virulence genes. Additionally, it has mobilizable genetic elements that may contribute to the dissemination of genetic determinants to other bacterial genera.

Cadmium-chelating ability of the siderophore DHBS secreted by Leclercia adecarboxylata FCH-CR2 and its action mechanism

As one of the most accumulative toxic heavy metals, cadmium (Cd) poses a major threat to human health. Bacterial siderophores, as small molecules with metal-absorbing ability, have great potential activity for Cd-reduction. In this study, the siderophore-producing bacterialstrain FCH-CR2 was isolated from a high-Cd contaminated soil using the CAS method. Leclercia adecarboxylata was identified through 16S rRNA sequence, homology analysis, colony morphology, physiological and biochemical tests. A siderophore, catechol type 2,3-dihydroxy-N-benzoyl-l-serine (DHBS) secreted by FCH-CR2, was purified using RP-HPLC and identified by LC-MS/MS. Intraperitoneal injection of DHBS significantly increased fecal Cd levels, and reduced Cd accumulation in organs. In density flooding theory (DFT) analysis, DHBS may bind to Cd via the hydroxyl site on the benzene ring. Besides, the isothermal titration calorimetry (ITC) assay revealed that the formation of Cd-DHBS is a spontaneous and endothermic reaction with ΔG = -21.4 kJ/mol and ΔH = 1.51 ± 0.142 kJ/mol.

A Rare Case of Multidrug-resistant Leclercia adecarboxylata Catheter-related Bloodstream Infection and an Updated Brief Literature Review

Leclercia adecarboxylata is a gram-negative bacillus, a ubiquitous microorganism, which may be found in both aquatic environments and soil, it was first described by H. Leclerc in 1962 and was reclassified thanks to more sensitive testing methods. L. adecarboxylata has been recently recognized as an emerging pathogen that causes several clinical syndromes not only in immunocompromised patients. 

Leclercia adecarboxylata in Peritoneal Dialysis Patients: A Systematic Review

Background:Leclercia adecarboxylata is a Gram-negative bacillus that can rarely cause infections in humans. We recently treated a case of peritonitis due to L. adecarboxylata in a peritoneal dialysis (PD) pediatric patient, and we systematically reviewed all the relevant reported cases in the literature. Methods: We searched the PubMed and Scopus databases, and we reviewed 13 such cases (2 children, 11 adults) that were reported, including our patient. Results: The mean (±SE) age was 53.2 ± 22.5 years, with a male-to-female ratio of approximately 1:1.6. Their mean vintage period on PD prior to L. adecarboxylata peritonitis was 37.5 ± 25.3 months. The VITEK card was the identification diagnostic tool in most cases (63%). The antimicrobial agent that was most frequently used was ceftazidime, which was implemented in 50% of cases as initial therapy, either as a monotherapy or combination therapy; in only two patients (15.3%) was the Tenkhoff catheter removed. The median duration of treatment was 18 days (range of 10-21 days), and all 13 patients that were reviewed were healed. Conclusions: Physicians should be aware that L. adecarboxylata is noted to rarely cause peritonitis in PD patients; however, this pathogen seems to be sensitive to most antimicrobial agents and can result in a favorable outcome with the selection of appropriate treatment.

Matrix-Assisted Laser Desorption Ionization Time of Flight (MALDI-TOF) as an Indispensable Tool in Diagnostic Bacteriology: A Comparative Analysis With Conventional Technique

INTRODUCTION

Owing to its accurate diagnosis, rapid turnaround time, cost effectivity, and less rates of error, Matrix-assisted Laser Desorption Ionization Time of Flight (MALDI-TOF) has replaced most of the phenotypic methods of identification. Thus, the objective of this study was to compare and evaluate MALDI-TOF MS to conventional biochemical-to identify bacterial microorganisms.

METHODS

Different bacterial species isolated from 2010 to 2018 (pre-MALDI-TOF era), using routine bio-chemicals were compared to bacterial species isolated from 2019 to August 2021 (post MALDI-TOF), using MALDI-TOF, in the microbiology laboratory of a tertiary care hospital in North India. Chi-Square test (χ2) was used for the evaluation of bacterial identification between biochemical tests and MALDI-TOF MS association with a 95% confidence interval, considering wrong identification in genera or at a species level.

RESULTS

Many different and new genera and species of bacteria could be identified using MALDI-TOF, which was not possible using only routine manual bio-chemicals like Kocuria rhizophilus, Rothia mucilaginosa, Enterococcus casseliflavus, Enterococcus gallinarum, Leuconostoc, Leclercia adecarboxylata, Raoultella ornithological, Cryseobacterium indologenes. Conclusion: Each of the newly identified bacteria played an important role in deciding treatment. Wide use of the MALDI-TOF system will not only strengthen diagnostic stewardship but also encourage antimicrobial stewardship programs.

Presence of Gram-negative bacteria and Staphylococcus aureus on the skin of blood donors in the Democratic Republic of the Congo

BACKGROUND

Skin bacteria may contaminate blood products but few data are available on sub-Saharan Africa (sSA). We assessed the presence of Gram-negative bacteria and Staphylococcus aureus on blood donor skin and evaluated skin antisepsis in the Democratic Republic of the Congo (DRC).

STUDY DESIGN AND METHODS

Among blood donors at the National Blood Transfusion Center (NBTC) and at a rural hospital, the antecubital fossa skin of the non-disinfected arm (not used for blood collection) was swabbed (25cm² surface) and cultured for total and Gram-negative bacterial counts. Bacteria were identified with MALDI-TOF and tested for antibiotic susceptibility by disk diffusion. For evaluation of the NBTC antisepsis procedure (i.e., ethanol 70%), the culture results of the disinfected arm (used for blood collection) were compared with those of the non-disinfected arm.

RESULTS

Median total bacterial counts on 161 studied non-disinfected arms were 1065 Colony-Forming Units (CFU) per 25 cm² , with 43.8% (70/160) of blood donors growing Gram-negative bacteria and 3.8% (6/159) Staphylococcus aureus (2/6 methicillin-resistant). Non-fermentative Gram-negative rods predominated (74/93 isolates, majority Pseudomonas spp., Acinetobacter spp.). Enterobacterales comprised 19/93 isolates (mostly Pantoea spp. and Enterobacter spp.), 5/19 were multidrug-resistant. In only two cases (1.9%, 2/108) the NBTC antisepsis procedure met the acceptance criterion of ≤2 CFU/25 cm² .

CONCLUSION

Skin bacterial counts and species among blood donors in DRC were similar to previously studied Caucasian populations, including cold-tolerating species and bacteria previously described in transfusion reactions. Prevention of contamination (e.g., antisepsis) needs further evaluation and customization to sSA.

Genomic insights of Leclercia adecarboxylata strains linked to an outbreak in public hospitals in Mexico

BACKGROUND

Leclercia adecarboxylata is a bacteria closely related to Escherichia coli according to its biochemical characteristics and is commonly considered non-pathogenic although a growing number of publications classify it as an emerging pathogen. Fosfomycin resistance is a common trait for L. adecarboxylata encoded by fosA^LA gene.

OBJECTIVE

To analyze genomic traits of sixteen L. adecarboxylata strains isolated from blood culture and a bottle of total parenteral nutrition.

METHODS

Twenty-eight L. adecarboxylata strains isolated from blood culture and a bottle of total parenteral nutrition were identified biochemically with a Vitek ® automated system. The strains were phenotyped by their growth on Eosin Methylene Blue agar or MacConkey agar plates. Additionally, Pulsed field gel electrophoresis (PFGE) was performed to establish the clonal relationship. The genomic DNA of sixteen strains was obtained using a Qubit ® dsDNA HS Assay Kit and sequenced on an Illumina ® MiSeq instrument. Draft genomes were assembled using PROKKA and Rast. Assemblies were submitted to Resfinder and PathogenFinder from the Center for Genomic Epidemiology in order to find resistance genes and pathogenic potential. IslandViewer4 was also used to find Pathogenicity and Phage Islands. For identification of the fosA gene, manual curation and Clustal analysis was performed. A novel FosA variant was identified. Finally, phylogenetic analysis was performed using VAMPhyRE software and Mega X.

RESULTS

In this paper, we report the genomes of sixteen strains of Leclercia adecarboxylata causing an outbreak associated with parenteral nutrition in public hospitals in Mexico. The genomes were analyzed for genetic determinants of virulence and resistance. A high pathogenic potential (pathogenicity index 0.82) as well as multiple resistance genes including carbapenemics, colistin and efflux pumps were determined. Based on sequence analysis, a new variant of the fosA^LA gene was described. Finally, the outbreak was confirmed by establishing the clonal relationship among the sixteen genomes obtained.

CONCLUSIONS

Commensal strains of L. adecarboxylata may acquire genetic determinants that provide mechanisms of host damage and go unnoticed in clinical diagnosis. L. adecarboxylata can evolve in a variety of ways including the acquisition of resistance and virulence genes representing a therapeutic challenge in patient care.

Cross-Over Pathogenic Bacteria Detected in Infected Tomatoes (Solanum lycopersicum L.) and Peppers (Capsicum annuum L.) in Bulgaria

The ability of certain human pathogens to adapt to plants without losing their virulence toward people is a major concern today. Thus, the aim of the present work was the investigation of the presence of cross-over pathogenic bacteria in infected tomato and pepper plants. The objects of the study were 21 samples from seven different parts of the plants and three from tomato rhizosphere. In total, 26 strains were isolated, identified by MALDI-TOF, and phenotypically characterized. The PCR amplification of the rpoB gene was applied as an approach for the rapid detection of cross-over pathogens in plant samples. A great bacterial diversity was revealed from tomato samples as nine species were identified (Leclercia adecarboxylata, Pseudesherichia vulneris, Enterobacter cancerogenus, Enterobacter cloacae, Enterobacter bugandensis, Acinetobacter calcoaceticus, Pantoea agglomerans, Pantoea ananatis, and Pectobacterium carotovorum). Polymicrobial contaminations were observed in samples T2 (tomato flower) and T10 (tomato fruit). Five species were identified from pepper samples (P. agglomerans, L. adecarboxylata, Pseudomonas sp., Pseudomonas putida, and Enterococcus sp.). Antibiotic resistance patterns were assigned in accordance with EFSA recommendations. All isolates showed varying resistance to the tested antibiotics. The genetic basis for the phenotypic antibiotic resistance was not revealed. No genes for the virulence factors were found among the population. To our knowledge, this is the first overall investigation of tomato and pepper cross-over pathogenic bacterial populations in Bulgaria.

Leclercia adecarboxylata infective endocarditis in a man with mitral stenosis: A case report and review of the literature

BACKGROUND

Infective endocarditis (IE) is a rare disease with a high mortality rate. Leclercia adecarboxylata (L. adecarboxylata) is a movable Gram-negative bacillus of enterobacteriaceae, and it can rarely be a pathogen which often affects immunodeficient patients. There are about three cases of immunocompetent patients with monomicrobial L. adecarboxylata infection. There are only three reported cases of IE caused by L. adecarboxylata in the world. The mitral valve is often affected in IE, and the prognosis for IE with mitral valve lesions is often poor.

CASE SUMMARY

A 51-year-old man was found to have moderate to severe mitral stenosis on echocardiography. He came to our Cardiothoracic Surgery Department for surgical management. A diastolic murmur was heard on auscultation of the heart in the mitral region. On the second day of hospitalisation, he presented with slurred speech, reduced muscle strength in the left limb, and acute cerebral infarction on cranial computed tomography. Surgical treatment was decided to postpone. On the ninth day of admission, the patient developed a sudden high fever and shock and was transferred to the Cardiac Intensive Care Unit, where echocardiogram revealed an anterior mitral valve leaflet vegetation. After empirical anti-infective treatment with vancomycin (1g q12h), an emergency valve replacement was performed. Bacterial culture identified L. adecarboxylata. Anti-infective treatment with piperacillin-tazobactam (4.5g q8h) was added for 4 wk. Follow-up echocardiography showed normal bioprosthetic valve function after mitral valve replacement.

CONCLUSION

We report the first case of L. adecarboxylata IE in China, and clinicians should pay attention to this pathogen.

Monomicrobial Joint Infection by Leclercia adecarboxylata in an Immunocompetent Patient After Knee Arthroscopy: A Case Report

CASE

A 54-year-old immunocompetent man presented to the office with severe right knee pain and swelling 27 days after knee arthroscopy. Additional diagnostics identified a monomicrobial infection of the right knee joint by the bacterium Leclercia adecarboxylata, which was later confirmed by repeated aspiration of the joint and culture of the aspirated fluid.

CONCLUSION

This case report details a postoperative monomicrobial infection with L. adecarboxylata after a knee arthroscopy in an immunocompetent host. Although infection by this bacterium is rare, this case demonstrates the possibility of L. adecarboxylata infection in the knee joint after orthopaedic surgery.

Leclercia pneumoniae sp. nov., a bacterium isolated from clinical specimen in Leipzig, Germany

Strain 49125T was isolated from an infant with pneumonia and septicaemia at the Leipzig University Hospital. Phenotypic and genomic traits were investigated. The strain's biochemical profile and its MALDI-TOF spectrogram did not differ from comparative samples of Leclercia adecarboxylata , thus far the sole member of the Leclercia species. A circular genome with a size of 4.4 Mbp and a G+C content of 55.0 mol% was reconstructed using hybrid Illumina and Nanopore sequencing. Phylogenetic analysis was based on 172 marker genes and validated using a k-mer-based search against a large genome collection including subsequent in silico DNA–DNA hybridization. Whole genome average nucleotide identity to any described species was below 95%, suggesting that strain 49125T represents a new species, for which we propose the name Leclercia pneumoniae sp. nov. with the type strain 49125T (=LMG 32245T=DSM 112336T).

Leclercia adecarboxylata catheter-related bacteraemia in an immunocompromised patient

A 34-year-old man on active chemotherapy was hospitalised with fever, chills and rigours after power-washing a pig pen on a farm. His blood cultures grew Leclercia adecarboxylata, a gram-negative rod in the Enterobacteriaceae family, which has been isolated from a variety of environments including soil, surface water, as well as in the gastrointestinal flora of farm animals. The likely source of infection was his tunnelled central venous catheter exposed to water contaminated by faeces when he was washing the pig pen. While there have been several cases reported of catheter-related L. adecarboxylata bacteraemia, to our knowledge there are very few reports of infection spread in this manner.

ENTEROBACTERIACEAE IN SOILS AND ATMOSPHERIC DUST AEROSOL ACCUMULATIONS OF MOSCOW CITY

The topsoils and atmospheric dust aerosols of the various areas of the city of Moscow were studied. Most of the dust samples contained a considerable number of particles enriched in phosphorus - a sign of contamination by feces. A variety of Enterobacteriaceae species, including opportunistic and pathogenic species, were isolated from the topsoil and dust samples and identified using 16S rDNA nucleotide sequences: Enterobacter aerogenes, E. agglomerans, E. cloacae, E. kobei, E. nimipressuralis, Escherichia coli, Citrobacter europaeus, Klebsiella granulomatis, K. grimontii, K. oxytoca, K. quasipneumoniae, K. variicola, Kluyvera ascorbate, Kluyvera intermedia, Leclercia adecarboxylata, Salmonella enterica and Trabulsiella guamensis. The greatest diversity of pathogens was isolated from spring soil and dust samples immediately after spring snowmelt. Antibiotic resistance of the isolated E. coli strains was tested using disks with a wide range of antimicrobial drugs: Amoxicillin, Ampicillin, Meropenem, Pefloxacin, Streptomycin, Ticarcillin+clavulanic acid, Fosfomycin, Ceftibuten, Ciprofloxacin. Resistance was observed in more than 22% of E. coli strains. The traffic area had a significant number of antibiotic-resistant E. coli strains, clearly indicating a high health risk from soil and dust exposure.

Two cases of Leclercia adecarboxylata septic arthritis in immunocompetent paediatric patients

Leclercia adecarboxylata is a rare cause of septic arthritis in children, and has intrinsic resistance to common antibiotics. We describe two cases of L. adecarboxylata septic arthritis in children that required re-presentation to hospital with prolonged treatment, and highlight the importance of considering L. adecarboxylata as a potential cause of infection among children with penetrating injuries and associated environmental exposure.

Leclercia adecarboxylata as Emerging Pathogen in Human Infections: Clinical Features and Antimicrobial Susceptibility Testing

(1) Background: Leclercia adecarboxylata (L. adecarboxylata) is a gram-negative bacillus of the Enterobacteriaceae family, which is uncommonly isolated from clinical specimens. L. adecarboxylata is considered as an aquatic opportunistic pathogen and most of the human infections are polymicrobial and usually occur in immunocompromised hosts. (2) Methods: In this retrospective study, we included all L. adecarboxylata strains since the introduction of MALDI-TOF MS in the Microbiology Department of Nord Franche-Comté Hospital, France (from 1 March 2015 to 31 July 2019). We studied demographic characteristics, comorbidities, characteristics of the current infection and outcome as well as antimicrobial susceptibility testing in all isolates. (3) Results: A total of 8 samples were identified (in 6 patients (4M/2F), with a recurrent L. adecarboxylata infection in 2 patients). The patients’ mean age was 66.2 years (range: 19–84). All patients were considered as immunocompetent, except a peritoneal dialysis patient with kidney transplantation. An exposition to an aquatic environment was identified in one patient. The most prevalent clinical feature was catheter-associated male urinary tract infection (in 3 cases) followed by ventilator-associated pneumonia (in 2 cases). One of 6 patients presented L. adecarboxylata bacteremia. L. adecarboxylata was part of a polymicrobial infection in 4 patients. The isolates showed a high susceptibility to all tested antibiotics, except one strain, which was resistant to fosfomycin. All patients with L. adecarboxylata infection were treated with antibiotics with a favorable outcome. (4) Conclusion: This study confirms the pathogenicity of L. adecarboxylata, even in immunocompetent patients, with a high susceptibility to antibiotics.

Leclercia adecarboxylata invasive infection in a patient with Hirschsprung disease: A case report

Introduction

Leclercia adecarboxylata is a ubiquitous aerobic, motile, gram-negative bacilli. The human gastro-intestinal tract is known to harbor this rarely opportunistic microorganism. We describe a rare case of invasive infection with a gastrointestinal starting point due to L. adecarboxylata in a patient with Hirschsprung disease.

Case report

It is about a newborn female who was admitted on the 3rd day of life to the neonatal intensive care unit for intestinal obstruction. On the 9th day of life, while managing the neonatal obstruction, the patient developed febrile peaks. Cytobacteriological examination of cerebrospinal fluid, blood cultures and culture of umbilical vein catheter allowed the exclusive isolation of Leclercia adecarboxylata. It was producing extended spectrum beta-lactamase and was treated with intravenous imipenem. After favourable evolution, the patient was transferred to the pediatric surgery department. There, she was diagnosed with Hirschsprung disease.

Discussion

Knowledge of the route of transmission of L. adecarboxylata is limited and the possible source of the infection is unclear. However, the authors describe three hypotheses of contamination of our propositus. In our patient, one or more of these routes of contamination would be possible. Indeed, bacteremia could occur as a result of a bacterial translocation across the mucosal barrier of the colon altered by Hirschsprung disease, antibiotic use and feeding practices.

Conclusion

Infection with L. adecarboxylata revealed a wide range of infection. It has only recently been acknowledged as an emerging pathogen. Further studies of the pathogenesis and risk factors are required.

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Leclercia adecarboxylata is Gram-negative bacillus as a member of the Enterobacteriaceae family.

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Infection with this rarely pathogenic microorganism has been limited to a small number of case reports. Of these, only few reports implicate the gastrointestinal tract as the focus of infection.

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Bacteremia could occur as a result of a bacterial translocation across the mucosal barrier of the colon altered by Hirschsprung disease, antibiotic use and feeding practices.

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As the number of L. adecarboxylata infections continues to expand so does our insight into its pathogenicity and role in human clinical infections. Further studies of the pathogenesis and risk factors are required.

In-Vitro Characterization of Growth Inhibition against the Gut Pathogen of Potentially Probiotic Lactic Acid Bacteria Strains Isolated from Fermented Products

Lactic acid bacteria (LAB) are probiotic candidates that may restore the balance of microbiota populations in intestinal microbial ecosystems by controlling pathogens and thereby promoting host health. The goal of this study was to isolate potential probiotic LAB strains and characterize their antimicrobial abilities against pathogens in intestinal microbiota. Among 54 LAB strains isolated from fermented products, five LAB strains (NSMJ15, NSMJ16, NSMJ23, NSMJ42, and NFFJ04) were selected as potential probiotic candidates based on in vitro assays of acid and bile salt tolerance, cell surface hydrophobicity, adhesion to the intestinal epithelium, and antagonistic activity. Phylogenetic analysis based on 16S rRNA genes showed that they have high similarities of 99.58-100% to Lacticaseibacillus paracasei strains NSMJ15 and NFFJ04, Lentilactobacillus parabuchneri NSMJ16, Levilactobacillus brevis NSMJ23, and Schleiferilactobacillus harbinensis NSMJ42. To characterize their antimicrobial abilities against pathogens in intestinal microbiota, the impact of cell-free supernatant (CFS) treatment in 10% (v/v) fecal suspensions prepared using pooled cattle feces was investigated using in vitro batch cultures. Bacterial community analysis using rRNA amplicon sequencing for control and CFS-treated fecal samples at 8 and 16 h incubation showed the compositional change after CFS treatment for all five LAB strains. The changed compositions were similar among them, but there were few variable increases or decreases in some bacterial groups. Interestingly, as major genera that could exhibit pathogenicity and antibiotic resistance, the members of Bacillus, Escherichia, Leclercia, Morganella, and Vagococcus were decreased at 16 h in all CFS-treated samples. Species-level classification suggested that the five LAB strains are antagonistic to gut pathogens. This study showed the probiotic potential of the five selected LAB strains; in particular, their antimicrobial properties against pathogens present in the intestinal microbiota. These strains would therefore seem to play an important role in modulating the intestinal microbiome of the host.

A case of Leclercia adecarboxylata endocarditis in a 62-year-old man

Leclercia adecarboxylata is a motile, gram negative bacillus in the Enterobacteriaceae family that is a rarely isolated cause of disease, despite being ubiquitous in nature. A 2019 review article identified only 74 reported cases, most often in immunocompromised patients [1]. The organism is generally susceptible to most antibiotics although multiantibiotic resistant strains have been reported. We report a case of a 62-year-old Caucasian man with multiple co-morbidities treated for L. adecarboxylata endocarditis with intravenous ceftriaxone.

Leclercia adecarboxylata Bacteremia without a Focus in a Non-Immunosuppressed Patient

BACKGROUND Leclercia adecarboxylata is a gram-negative rod, which is normally found in water and food. It is an emerging pathogen that affects immunocompromised patients, including patients with hematological malignancies or those receiving chemotherapy. Generally, L. adecarboxylata is considered a low-virulence pathogen with an excellent susceptibility profile, but some strains may be resistant to multiple antibiotics, such as b-lactams. Moreover, L. adecarboxylata is usually isolated as a part of polymicrobial cultures in immunocompetent individuals, but there have been cases where it was the only isolate. CASE REPORT A 74-year-old woman who was non-immunosuppressed and had multiple comorbidities was admitted with acute decompensated heart failure due to pneumonia. She was treated with multiple courses of antibiotics including amoxicillin-clavulanate and ciprofloxacin for pneumonia, but her infection worsened, and she had cardiopulmonary arrest. After resuscitation, she was stable for several days but suddenly became confused and hypotensive. The septic screen showed L. adecarboxylata bacteremia without a clear source, which was treated successfully with meropenem for 14 days. After the meropenem course, the patient developed diarrhea and was found to have severe Clostridium difficile infection. She did not respond to oral vancomycin and intravenous metronidazole and died. CONCLUSIONS This case illustrated an infection in a non-immunosuppressed individual by an organism that is considered an opportunistic pathogen, mainly affecting immunocompromised patients. The patient's blood culture grew L. adecarboxylata, which was sensitive to all antibiotics but resolved with meropenem treatment. Owing to increasing L. adecarboxylata infections, we recommend further studies to understand the organism's pathogenesis, risk factors, and resistance pattern.

Leclercia adecarboxylata urinary tract infection in a patient with bladder cancer and recurrent hematuria

Leclercia adecarboxylata is an rare human pathogen, mostly affecting immunocompromised individuals or as one microbe in polymicrobial infections in immunocompetent patients. L. adecarboxylata is rarely isolated from the urinary tract. We describe a case of pan-sensitive L. adecarboxylata isolated from a polymicrobial urinary tract infection from an immunocompetent older adult with recently diagnosed bladder cancer.

Molecular investigation of an outbreak associated with total parenteral nutrition contaminated with NDM-producing Leclercia adecarboxylata

Background

This study aimed to determine the epidemiological, microbiological, and molecular characteristics of an outbreak of carbapenem-resistant Leclercia adecarboxylata in three hospitals associated with the unintended use of contaminated total parental nutrition (TPN).

Methods

For 10 days, 25 patients who received intravenous TPN from the same batch of a formula developed sepsis and had blood cultures positive for L. adecarboxylata. Antimicrobial susceptibility and carbapenemase production were performed in 31 isolates, including one from an unopened bottle of TPN. Carbapenemase-encoding genes, extended-spectrum β-lactamase–encoding genes were screened by PCR, and plasmid profiles were determined. Horizontal transfer of carbapenem resistance was performed by solid mating. Clonal diversity was performed by pulsed-field gel electrophoresis. The resistome was explored by whole-genome sequencing on two selected strains, and comparative genomics was performed using Roary.

Results

All 31 isolates were resistant to aztreonam, cephalosporins, carbapenems, trimethoprim/sulfamethoxazole, and susceptible to gentamicin, tetracycline, and colistin. Lower susceptibility to levofloxacin (51.6%) and ciprofloxacin (22.6%) was observed. All the isolates were carbapenemase producers and positive for bla_NDM-1, bla_TEM-1B, and bla_SHV-12 genes. One main lineage was detected (clone A, 83.9%; A1, 12.9%; A2, 3.2%). The bla_NDM-1 gene is embedded in a Tn125-like element.

Genome analysis showed genes encoding resistance for aminoglycosides, quinolones, trimethoprim, colistin, phenicols, and sulphonamides and the presence of IncFII (Yp), IncHI2, and IncHI2A incompatibility groups. Comparative genomics showed a major phylogenetic relationship among L. adecarboxylata I1 and USDA-ARS-USMARC-60222 genomes, followed by our two selected strains.

Conclusion

We present epidemiological, microbiological, and molecular evidence of an outbreak of carbapenem-resistant L. adecarboxylata in three hospitals in western Mexico associated with the use of contaminated TPN.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-05923-0.

Eobania vermiculata as a potential indicator of nitrate contamination in soil

The effects of nitrates were analysed on the land snail Eobania vermiculata, a good bioindicator to assess the effects of certain pollutants in soil. It is known that the molluscs are very sensitive to contamination substances and can be used as sentinel organism for environmental pollution assessment. The nitrates are present in fertilizers and in food additives and their excess can not only be harmful to the environment but also dangerous for the humans. Indeed, in the mammals the nitrates are converted into nitrites and can cause a series of complications as the formation of methaemoglobin and cancers. In this study, adult organisms of E. vermiculata were exposed to soil containing 2000 mg/L of nitrates for 30 days to evaluate the stool microbiome and the histological changes at the level of the foot. Eggs of these snails were similarly treated to observe their hatching, survival and development. Histological changes were observed at level of the foot of adult snails exposed to nitrate and in their stools was evident an increase of bacteria, especially those that have a high ability to exploit nitrates and nitrogen as nutrients. Instead, the treated eggs showed changes in hatching, hypopigmentation of newborn snails and a decrease of their survival in time. The overall information obtained from these endpoints can provide important information regarding the quality of the environment. In addition, they also showed that the invertebrate organism E. vermiculata despite being a simple organism is very useful and efficient for ecotoxicological studies.

Leclercia Adecarboxylata Causing Necrotizing Fasciitis in an Immunocompetent Athlete Injecting Illicit Testosterone Supplements

Leclercia adecarboxylata (L. adecarboxylata) is an uncommon and often misdiagnosed cause of multiple infection types including skin and soft tissue, cholecystitis, and septicemia. It commonly afflicts immunocompromised hosts or individuals who experience trauma in aquatic environments. We present a case where this bacteria causes necrotizing fasciitis as a consequence of injecting street bought testosterone supplements. This patient was treated successfully with excisional debridement of the wound as well as a one week course of Linezolid and Bactrim. 

Leclercia adecarboxylata causing necrotising soft tissue infection in an immunocompetent adult

A 72-year-old woman presented with concern for a necrotising soft tissue infection (NSTI) 6 days after a tree branch impaled her left lower extremity while hiking in Hawaii. The wound was irrigated and closed at a local clinic in Hawaii. She completed a 5-day course of clindamycin. She presented to our emergency department 1 day after completion of antibiotics due to worsening erythema and malodorous drainage. Local wound exploration revealed bullae and easy dissection of fascial planes. CT scan revealed complex heterogeneous fluid and inflammatory stranding in the posterior calf. Clinical and radiographic findings raised concern for NSTI prompting initiation of broad spectrum antibiotics and urgent operative debridement. Wound cultures and deep tissues cultures returned positive for pansusceptible Leclercia adecarboxylata She underwent two additional operative debridements and transitioned to negative pressure wound therapy during her hospitalisation. She was discharged home on oral amoxicillin/clavulanate on hospital day 6.

Leclercia adecarboxylata: An Emerging Pathogen Among Pediatric Infections

Leclercia adecarboxylata is a gram-negative bacillus of the Enterobacteriaceae family. It is a rare human pathogen that is often acquired via wound and/or contact with aquatic environment. Although multiple cases of L. adecarboxylata infections are described in the adult population, few have been documented in pediatrics. We will present two cases of L. adecarboxylata infections in the pediatric population. The first is a case of cellulitis in an 11-year-old male patient after a penetrating wound. The second is a first-documented urinary tract infection in a 16-year-old male patient with chronic kidney disease. Both patients were successfully treated with antibiotics and surgical intervention, if necessary. These cases highlight the growing emergence of this bacterium in the pediatric population and the need to become more aware of its threat even in patients who are immunocompetent.

Leclercia adecarboxylata From Human Gut Flora Carries mcr-4.3 and bla IMP-4-Bearing Plasmids

A clinical Leclercia adecarboxylata strain harboring the mcr-4.3 and bla _IMP-4 genes was isolated from active rectal screening of carbapenem-resistant Enterobacteriaceae (CRE) in a patient. The isolate was found to harbor seven plasmids, including a 94,635 bp bla _IMP-4-bearing IncN plasmid and a 9,782 bp mcr-4.3-bearing ColE10-type plasmid. The isolate was susceptible to colistin despite carrying the mcr-4.3 gene, suggesting that this MCR-4 variant may not be functional. Carriage of antibiotic resistance genes in human gut L. adecarboxylata strain suggests that close surveillance of resistance strains in the human gut flora should be included as a routine clinical practice to prevent occurrence of infections, especially among immunocompromised patients.

First Report of Coexistence of Three Different MDR Plasmids, and That of Occurrence of IMP-Encoding Plasmid in Leclercia adecarboxylata

Three different MDR plasmids p16005813A, p16005813B, and p16005813C, which carried a total of 18 non-redundant resistance genes or gene loci, were identified in a single clinical isolate of Leclercia adecarboxylata. The p16005813A backbone showed very low levels of identity to all DNA sequences available in public databases and carried a repA gene that could not assigned into any of known incompatibility groups. The IncFII-family p16005813B and pECAZ161_KPC had essentially identical backbones. p16005813C belonged to an IncR single-replicon plasmid. p16005813A, p16005813B, and p16005813C harbored three different novel MDR regions as their sole accessory modules. The MDR region of p16005813B manifested as Tn6505, which was generated from insertion of bla_IMP–8-carrying In655 instead of In4 into the Tn1696 backbone. Other key antibiotic resistance elements included Tn2, IS26–mph(A)–mrx–mphR(A)–IS6100 unit, chrA region, In27, and aacC2–tmrB region in the MDR region of p16005813A, and ΔTn9 carrying catA1, In609, and IS26–tetA(C)–tetR(C)–IS26 unit in the MDR region of p16005813C. This was the first report of coexistence of three different MDR plasmids, and that of occurrence of IMP-encoding plasmid and bla_IMP–8 gene in L. adecarboxylata.

Leclercia adecarboxylata Cholecystitis with Septic Shock in Immunocompetent Patient

L. adecarboxylata is a Gram-negative rod previously named Escherichia adecarboxylata, isolated as normal flora in the gut of animals including human stool. Most reported cases refer to immunocompromised patients with polymicrobial infections and water environments. Here we present a case of 51-year-old immunocompetent female presented with nausea, vomiting, malaise, and subjective fever for few days. On examination, she was drowsy but arousable and oriented to person, place, time, and situation. Her abdomen was tender globally and more tender in the epigastric area. Vitals showed a temperature of 37°C, pulse of 110 beats/min, blood pressure of 75/50 mmHg, and oxygen saturation of 91% on room air. An HIV panel and hepatitis panel were negative. Liver and gallbladder ultrasound was performed, revealing multiple nonmobile stones with shadowing noted within the gallbladder sac, a thickened gallbladder wall, and a moderate amount of pericholecystic fluid. Broad spectrum antibiotics, crystalloid fluids, and vasopressors were initiated. A few hours after admission she developed respiratory failure for which she underwent endotracheal intubation. An ultrasound guided gallbladder drain was performed. Culture of the biliary fluid yielded pure growth of pan-sensitive L. adecarboxylata; antibiotics were narrowed accordingly. The patient was on the maximum doses of vasopressin, norepinephrine, and epinephrine with a blood pressure of 75/45 and a mean arterial pressure of 51. She passed away on the fourth day of admission.