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1.
Emerg Infect Dis ; 30(8): 1545-1554, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39043387

RESUMEN

Human infections with Corynebacterium diphtheriae species complex (CdSC) bacteria were rare in French Guiana until 2016, when the number of cases diagnosed increased. We conducted an epidemiologic, multicenter, retrospective study of all human CdSC infections diagnosed in French Guiana during January 1, 2016-December 31, 2021. A total of 64 infectious episodes were observed in 60 patients; 61 infections were caused by C. diphtheriae and 3 by C. ulcerans. Estimated incidence increased from 0.7 cases/100,000 population in 2016 to 7.7 cases/100,000 population in 2021. The mean patient age was 30.4 (+23.7) years, and male-to-female ratio was 1.7:1 (38/22). Of the 61 C. diphtheriae isolates, 5 tested positive for the diphtheria toxin gene, and all results were negative by Elek test; 95% (61/64) of cases were cutaneous, including the C. ulcerans cases. The increase in reported human infections underscores the need to raise awareness among frontline healthcare practitioners to improve prevention.


Asunto(s)
Corynebacterium diphtheriae , Difteria , Humanos , Guyana Francesa/epidemiología , Estudios Retrospectivos , Femenino , Masculino , Corynebacterium diphtheriae/aislamiento & purificación , Corynebacterium diphtheriae/genética , Adulto , Persona de Mediana Edad , Adolescente , Niño , Adulto Joven , Preescolar , Difteria/epidemiología , Difteria/microbiología , Anciano , Incidencia , Lactante , Historia del Siglo XXI , Infecciones por Corynebacterium/epidemiología , Infecciones por Corynebacterium/microbiología
2.
Mikrobiyol Bul ; 58(3): 239-258, 2024 Jul.
Artículo en Turco | MEDLINE | ID: mdl-39046207

RESUMEN

An increasing number of different clinical infections caused by Corynebacteria have been reported in the last decade. The aim of this study was to evaluate the antibiotic resistance rates, biofilm formation capacities and to investigate the ''anti-quorum-sensing (anti-QS)'' activities of corynebacteria, which were divided into three groups according to the type of growth in culture (pure, with another pathogenic bacterium and polymicrobial growth). In total 240 Corynebacterium spp. isolates from different clinical specimens sent to the medical microbiology laboratories of Düzce University Faculty of Medicine Hospital and Basaksehir Çam and Sakura City Hospital between June 2021 and June 2022 were classified into three groups: pure, isolated with another pathogen and polymicrobial, according to their growth patterns in culture. Bacteria were identified by matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) Biotyper (Bruker, Germany) at an external centre. Antibiotic susceptibilities were determined by disc diffusion method and for vancomycin broth microdilution method was used. Results were interpreted according to EUCAST recommendations. The biofilm-forming properties of the isolates were determined quantitatively. Bioactive components of 17 isolates with strong biofilm formation were extracted and anti-QS activity was determined by agar diffusion method using Chromobacterium violaceum ATCC 12472 strain and then violacein pigment production was measured quantitatively. Of the 240 Corynebacterium spp. isolates, 138 (58%) were pure, 52 (22%) were isolated with another pathogen and 50 (20%) were part of a polymicrobial infection. Of the isolates, 140 were identified as C.striatum, 34 as C.amycolatum and 24 as Corynebacterium afermentans. When the antibiotic resistance rates of the Corynebacterium isolates were analysed according to the groups, the resistance rates to rifampicin and tetracycline antibiotics were found to be statistically significantly lower in the polymicrobial group than in the other groups. The resistance rates to penicillin, clindamycin, ciprofloxacin, moxifloxacin, rifampicin, tetracycline and linezolid were 96.7%, 88.3%, 86.3%, 73.8%, 62.5%, 59.2% and 0.8%, respectively. While all isolates were susceptible to vancomycin, linezolid resistance was detected in two C.afermentans isolates. When the biofilm formation ability was analysed, it was observed that 87 (36.3%) isolates formed biofilm. The biofilm formation rate of the isolates in the polymicrobial growth group was lower than the other two groups. The anti-QS activity of 17 isolates with strong biofilm formation was investigated and none of the Corynebacterium extracts tested were found to have anti-QS activity (inhibition of violacein pigment production without inhibiting bacterial growth) in the QS study with C.violaceum, whereas five isolate extracts had antibacterial activity (inhibition of bacterial growth). Four of the bacterial extracts with antimicrobial activity belonged to C.amycolatum and one to C.afermentans. In conclusion, when both antibiotic resistance rates and biofilm formation rates were analysed, the corynebacteria growing in culture with another pathogen showed similar characteristics to the corynebacteria growing as a pure culture. Therefore, it was thought that corynebacteria growing with another pathogen should not be ignored. In addition, the antimicrobial effects of some corynebacterial extracts suggested that more QS studies should be carried out with microbiota bacteria.


Asunto(s)
Antibacterianos , Biopelículas , Infecciones por Corynebacterium , Corynebacterium , Pruebas de Sensibilidad Microbiana , Percepción de Quorum , Biopelículas/efectos de los fármacos , Biopelículas/crecimiento & desarrollo , Corynebacterium/efectos de los fármacos , Corynebacterium/aislamiento & purificación , Corynebacterium/crecimiento & desarrollo , Humanos , Antibacterianos/farmacología , Infecciones por Corynebacterium/microbiología , Percepción de Quorum/efectos de los fármacos , Farmacorresistencia Bacteriana , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Indoles/farmacología
3.
mSystems ; 9(7): e0048424, 2024 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-38934644

RESUMEN

Corynebacterium pseudotuberculosis (C. p), a facultative intracellular bacterium, is an important zoonotic pathogen that causes abscesses and pyogenic granulomas. The relationship between gut microbiota and host health or diseases has received increasing attention. However, the role of gut microbiota in the process of C. p infection is still unclear. In this study, we established a C. p infection model in C57BL/6 mice and examined the impact of preemptive oral administration Lactobacillus acidophilus (L. acidophilus) on infection. Our findings revealed that C. p infection led to pronounced pathological alterations in the liver and kidneys, characterized by abscess formation, intense inflammatory responses, and bacterial overload. Remarkably, these deleterious effects were greatly relieved by oral administration of L. acidophilus before infection with C. p. Additionally, we further found that during C. p infection, peritoneal macrophages (PMs) of mice orally administered with L. acidophilus accumulated more rapidly at sites of infection. Furthermore, our results showed that PMs from mice with oral L. acidophilus administration showed a stronger C. p clearance effect, and this was mediated by high expression of LC3-II protein. Meanwhile, oral administration of L. acidophilus protected the gut microbiota disorder in C57BL/6 mice caused by C. p infection. In summary, our study demonstrates that oral administration of L. acidophilus confers effective protection against C. p infection in C57BL/6 mice by modulating macrophage autophagy, thereby augmenting bacterial clearance and preserving gut microbiota and function stability. These findings position L. acidophilus as a viable probiotic candidate for the clinical prevention of C. p infection. IMPORTANCE: Corynebacterium pseudotuberculosis (C. p) is known to induce a range of chronic diseases in both animals and humans. Currently, clinical treatment for C. p infection mainly relies on antibiotic therapy or surgical intervention. However, excessive use of antibiotics may increase the risk of drug-resistant strains, and the effectiveness of treatment remains unsatisfactory. Furthermore, surgical procedures do not completely eradicate pathogens and can easily cause environmental pollution. Probiotic interventions are receiving increasing attention for improving the body's immune system and maintaining health. In this study, we established a C. p infection model in C57BL/6 mice to explore the impact of Lactobacillus acidophilus during C. p infection. Our results showed that L. acidophilus effectively protected against C. p infection by regulating the autophagy of macrophages and maintaining intestinal microbiota homeostasis. This study may provide a new strategy for the prevention of C. p infection.


Asunto(s)
Autofagia , Infecciones por Corynebacterium , Corynebacterium pseudotuberculosis , Microbioma Gastrointestinal , Lactobacillus acidophilus , Ratones Endogámicos C57BL , Animales , Autofagia/efectos de los fármacos , Microbioma Gastrointestinal/efectos de los fármacos , Microbioma Gastrointestinal/fisiología , Lactobacillus acidophilus/fisiología , Ratones , Infecciones por Corynebacterium/prevención & control , Infecciones por Corynebacterium/microbiología , Homeostasis/efectos de los fármacos , Probióticos/administración & dosificación , Probióticos/farmacología , Macrófagos Peritoneales/inmunología , Macrófagos Peritoneales/microbiología , Macrófagos Peritoneales/efectos de los fármacos , Macrófagos Peritoneales/metabolismo , Macrófagos/inmunología , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Modelos Animales de Enfermedad
5.
Microb Pathog ; 192: 106671, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38729381

RESUMEN

This work evaluated aspects of the immune response of BALB/c mice infected with Corynebacterium pseudotuberculosis (T1 and C57). The fifteen BALB/c mice were euthanized after 70 days of infection and morphologically evaluated, also analyzing the innate and adaptive immune responses. The C57 strain induced more pronounced morphological changes than the T1 strain. There was an increase in CD4+ and CD8+ T cells identified during infection with the C57 strain. Cytokines of the inflammatory profile IL-1α and IL-6 and regulatory IL-13 and IL-10 presented significant differences. Cytokines IL-2, IL-4, INF-γ, IL-22, IL-21, and IL-27 did not differ significantly between groups. The obtained results contribute to a better understanding of the type of response and the immunological mechanisms involved during infection with different strains of C. pseudotuberculosis.


Asunto(s)
Linfocitos T CD8-positivos , Infecciones por Corynebacterium , Corynebacterium pseudotuberculosis , Citocinas , Ratones Endogámicos BALB C , Animales , Corynebacterium pseudotuberculosis/inmunología , Infecciones por Corynebacterium/inmunología , Infecciones por Corynebacterium/microbiología , Ratones , Citocinas/metabolismo , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD4-Positivos/inmunología , Interleucina-10 , Inmunidad Adaptativa , Inmunidad Innata , Interleucina-6 , Modelos Animales de Enfermedad , Ratones Endogámicos C57BL , Interleucina-1alfa/metabolismo , Interleucina-1alfa/inmunología , Interferón gamma/metabolismo , Interleucina-4/metabolismo , Interleucinas , Interleucina-2/metabolismo
6.
Eur J Clin Microbiol Infect Dis ; 43(7): 1495-1501, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38801486

RESUMEN

Corynebacterium striatum is an emerging nosocomial pathogen. This is the first report showing the presence of three distinct multidrug resistant lineages of C. striatum among patients in a UK hospital. The presence of ErmX, Tet(W), Bla and AmpC proteins, and mutations in gyrA gene are associated with the resistance to clindamycin, doxycycline, penicillin and moxifloxacin, respectively. These strains are equipped with several corynebacterial virulence genes including two SpaDEF-type and a novel pilus gene cluster, which needs further molecular characterisation. This study highlights a need of developing an active surveillance strategy for routine monitoring and preventing potential cross-transmission among susceptible patients.


Asunto(s)
Antibacterianos , Infecciones por Corynebacterium , Corynebacterium , Farmacorresistencia Bacteriana Múltiple , Filogenia , Centros de Atención Terciaria , Humanos , Corynebacterium/genética , Corynebacterium/efectos de los fármacos , Corynebacterium/aislamiento & purificación , Corynebacterium/clasificación , Farmacorresistencia Bacteriana Múltiple/genética , Infecciones por Corynebacterium/microbiología , Infecciones por Corynebacterium/epidemiología , Reino Unido/epidemiología , Antibacterianos/farmacología , Pruebas de Sensibilidad Microbiana , Infección Hospitalaria/microbiología , Infección Hospitalaria/epidemiología , Masculino , Factores de Virulencia/genética , Proteínas Bacterianas/genética , Femenino
7.
Open Vet J ; 14(1): 25-31, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38633174

RESUMEN

Background: Affection with Corynebacterium pseudotuberculosis (C. pseudotuberculosis) and development of cellulitis and/or abscess formation with cutaneous lymphangitis in cattle is rare to some extent, so literature about the biochemical changes that would accompany this infection is rare. Aim: In this context, the present study was designed to screen the effect of the infection with C. pseudotuberculosis cutaneous lymphangitis on the release of some immune molecules, organ functions, and redox state in Baladi cows. Methods: Fourteen Baladi cows from a small dairy farm in El-Behira, Egypt, were selected to complete this study. After bacteriological culture confirmation, seven of them were found suffering from cutaneous lesions due to infection with C. pseudotuberculosis (Diseased group), while the others were healthy (Healthy group). Serum samples were obtained to evaluate the presumptive changes in some clinicopathological parameters. Results: Serum analysis revealed a significant decrease in the levels of interferon-gamma and interleukin-17 as well as a significant decrement in the concentration of beta-defensin (ß-defensin) and lipocalin-2. While serum level of interleukin-10 recorded a significant increase in these animals when compared to healthy control animals. Concurrently, the affected animals recorded a significant elevation in serum levels of hepato-cardiac enzymes, urea, and creatinine in addition to disturbance in the serum redox state. Conclusion: In conclusion, infection with C. pseudotuberculosis cattle may disturb the defensive immune state, body organ function, and redox state of the animals.


Asunto(s)
Enfermedades de los Bovinos , Infecciones por Corynebacterium , Linfangitis , beta-Defensinas , Femenino , Bovinos , Animales , Linfangitis/veterinaria , Citocinas , Inflamación/veterinaria , Enfermedades de los Bovinos/microbiología , Infecciones por Corynebacterium/microbiología , Infecciones por Corynebacterium/patología , Infecciones por Corynebacterium/veterinaria
8.
Rinsho Ketsueki ; 65(4): 243-248, 2024.
Artículo en Japonés | MEDLINE | ID: mdl-38684434

RESUMEN

Patient 1 was a 70-year-old woman with refractory diffuse large B-cell lymphoma who received allogeneic peripheral blood stem cell transplantation from an HLA-haploidentical related donor. Upper back pain appeared on day63, and Th8-Th9 pyogenic spondylitis was diagnosed based on magnetic resonance imaging (MRI). Blood culture on day14 identified Corynebacterium striatum as the causative bacteria of blood stream infection (BSI). The pyogenic spondylitis resolved after treatment with daptomycin for 2 months. Patient 2 was a 65-year-old man with relapsed angioimmunoblastic T-cell lymphoma who received bone marrow transplantation from an HLA-DR single-antigen-mismatched unrelated donor. Lower back pain appeared on day30, and L4-L5 pyogenic spondylitis was diagnosed based on MRI. Blood culture was negative. Daptomycin and clindamycin were selected for treatment based on the drug susceptibility of bacteria that had caused pre-engraftment BSI (Escherichia coli on day3 and Corynebacterium striatum on day9), and the pyogenic spondylitis resolved after 6 months of this treatment. Pyogenic spondylitis should be considered in the differential diagnosis of back pain accompanied by BSI before engraftment in allogeneic hematopoietic stem cell transplant recipients.


Asunto(s)
Infecciones por Corynebacterium , Trasplante de Células Madre Hematopoyéticas , Espondilitis , Anciano , Femenino , Humanos , Masculino , Corynebacterium/aislamiento & purificación , Infecciones por Corynebacterium/diagnóstico , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Linfoma de Células B Grandes Difuso/terapia , Espondilitis/microbiología , Espondilitis/terapia , Trasplante Homólogo/efectos adversos
9.
Braz J Microbiol ; 55(2): 1405-1414, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38598149

RESUMEN

BACKGROUND: Corynebacterium spp. are widely disseminated in the environment, and they are part of the skin and mucosal microbiota of animals and humans. Reports of human infections by Corynebacterium spp. have increased considerably in recent years and the appearance of multidrug resistant isolates around the world has drawn attention. OBJECTIVES: To describe a new species of Corynebacterium from human tissue bone is described after being misidentified using available methods. METHODS: For taxonomic analyses, phylogenetic analysis of 16S rRNA and rpoB genes, in silico DNA-DNA hybridization, average nucleotide and amino acid identity, multilocus sequence analysis, and phylogenetic analysis based on the complete genome were used. FINDINGS: Genomic taxonomic analyzes revealed values of in silico DNA-DNA hybridization, average nucleotide and amino acids identity below the values necessary for species characterization between the analyzed isolates and the closest phylogenetic relative Corynebacterium aurimucosum DSM 44532T. MAIN CONCLUSIONS: Genomic taxonomic analyzes indicate that the isolates analyzed comprise a new species of the Corynebacterium genus, which we propose to name Corynebacterium hiratae sp. nov. with isolate 332T (= CBAS 826T = CCBH 35,014T) as the type strain.


Asunto(s)
Infecciones por Corynebacterium , Corynebacterium , ADN Bacteriano , Filogenia , ARN Ribosómico 16S , Corynebacterium/genética , Corynebacterium/clasificación , Corynebacterium/aislamiento & purificación , Humanos , ARN Ribosómico 16S/genética , ADN Bacteriano/genética , Infecciones por Corynebacterium/microbiología , Huesos/microbiología , Tipificación de Secuencias Multilocus , Genoma Bacteriano , Técnicas de Tipificación Bacteriana , Hibridación de Ácido Nucleico
10.
J Appl Microbiol ; 135(4)2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38587823

RESUMEN

AIM: In this study, it was aimed to examine the antibacterial activity of the essential oil components (EOCs), carvacrol (CAR), cinnamaldehyde (CIN), thymol (TH), alpha pinene (α-PN), eucalyptol (EU), limonene (LIM), and the antibiotics, linezolid (LZD), vancomycin (VAN), gentamicin (GEN), ciprofloxacin (CIP), clindamycin (CLN), and penicillin (PEN) against 50 multidrug resistant Corynebacterium striatum strains, and the synergistic interactions of CAR and CIN with the antibiotics against 10 randomly selected Coryne. striatum strains to explore synergistic interactions to determine if their combined use could enhance antibiotic activity and potentially reduce resistance. METHODS AND RESULTS: The activity of the EOCs and the antibiotics against Coryne. striatum strains isolated from clinical specimens, was examined by broth microdilution method. The synergistic interactions of the EOCs with the antibiotics against 10 randomly selected Coryne. striatum strains were determined by checkerboard method. EOCs, CIN, and CAR and antibiotics, LZD, VAN, GEN, CIP, and CLN were detected to have antibacterial activity against Coryne. striatum strains alone and either synergistic interactions were observed in combinations of the antibiotics with EOCs. CONCLUSIONS: All Coryne. striatum strains were determined to be susceptible to VAN and LZD and resistant to GEN, PEN, CIP, and CLN. Synergistic interactions were observed in all combinations of antibiotics tested with CAR and CIN.


Asunto(s)
Acroleína , Acroleína/análogos & derivados , Antibacterianos , Corynebacterium , Farmacorresistencia Bacteriana Múltiple , Sinergismo Farmacológico , Pruebas de Sensibilidad Microbiana , Monoterpenos , Aceites Volátiles , Antibacterianos/farmacología , Corynebacterium/efectos de los fármacos , Aceites Volátiles/farmacología , Farmacorresistencia Bacteriana Múltiple/efectos de los fármacos , Acroleína/farmacología , Monoterpenos/farmacología , Cimenos/farmacología , Ciprofloxacina/farmacología , Gentamicinas/farmacología , Vancomicina/farmacología , Linezolid/farmacología , Limoneno/farmacología , Eucaliptol/farmacología , Timol/farmacología , Clindamicina/farmacología , Humanos , Penicilinas/farmacología , Terpenos/farmacología , Ciclohexenos/farmacología , Infecciones por Corynebacterium/microbiología
11.
Front Cell Infect Microbiol ; 14: 1361045, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38572320

RESUMEN

Introduction: Over the past decade, Corynebacterium striatum (C. striatum), an emerging multidrug-resistant (MDR) pathogen, has significantly challenged healthcare settings, especially those involving individuals with weakened immune systems. The rise of these superbugs necessitates innovative solutions. Methods: This study aimed to isolate and characterize bacteriophages targeting MDR-C. striatum. Utilizing 54 MDR-C. striatum isolates from a local hospital as target strains, samples were collected from restroom puddles for phage screening. Dot Plaque and Double-layer plate Assays were employed for screening. Results: A novel temperate bacteriophage, named CSP1, was identified through a series of procedures, including purification, genome extraction, sequencing, and one-step growth curves. CSP1 possesses a 39,752 base pair circular double-stranded DNA genome with HK97-like structural proteins and potential for site-specific recombination. It represents a new species within the unclassified Caudoviricetes class, as supported by transmission electron microscopy, genomic evolutionary analysis, and collinearity studies. Notably, CSP1 infected and lysed 21 clinical MDR-C. striatum isolates, demonstrating a wide host range. The phage remained stable in conditions ranging from -40 to 55°C, pH 4 to 12, and in 0.9% NaCl buffer, showing no cytotoxicity. Discussion: The identification of CSP1 as the first phage targeting clinical C. striatum strains opens new possibilities in bacteriophage therapy research, and the development of diagnostic and therapeutic tools against pathogenic bacteria.


Asunto(s)
Bacteriófagos , Infecciones por Corynebacterium , Humanos , Bacteriófagos/genética , Corynebacterium/genética , Infecciones por Corynebacterium/microbiología , Genómica , Antibacterianos
14.
Leuk Lymphoma ; 65(7): 997-1002, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38498769

RESUMEN

Corynebacterium is generally considered a contaminant in clinical practice. However, it may cause bacteremia in patients with hematologic disorders, and factors that contribute to its mortality are unclear. A case series and systematic literature review identified 96 cases of Corynebacterium bacteremia inhematologic disorderpatients. The median age was 50.5 years (range: 2-93 years), with 79 (82%) patients 18 years or older, and 64 (67%) patients male. Most cases involved hematologic malignancies, and neutropenia was observed in approximately 75% cases. The most common sites of infection/symptoms were skin and soft tissue, respiratory, and catheter-related bloodstream infection. The infection-related mortality was 23%, and univariate analysis showed that age, respiratory infection/symptoms, and source control were significantly associated with infection-related mortality. Multivariate analysis indicates that infection-related mortality was significantly reduced by source control (OR: 0.24, 95% CI: 0.06-0.97, p = 0.046). Therefore, when Corynebacterium infections are suspected, early source control should be considered.


Asunto(s)
Bacteriemia , Infecciones por Corynebacterium , Corynebacterium , Enfermedades Hematológicas , Humanos , Bacteriemia/microbiología , Bacteriemia/diagnóstico , Bacteriemia/etiología , Infecciones por Corynebacterium/complicaciones , Infecciones por Corynebacterium/diagnóstico , Infecciones por Corynebacterium/microbiología , Corynebacterium/aislamiento & purificación , Anciano , Adulto , Persona de Mediana Edad , Anciano de 80 o más Años , Masculino , Adolescente , Enfermedades Hematológicas/complicaciones , Enfermedades Hematológicas/microbiología , Adulto Joven , Femenino , Niño , Preescolar , Factores de Riesgo
15.
J Antimicrob Chemother ; 79(5): 1023-1029, 2024 05 02.
Artículo en Inglés | MEDLINE | ID: mdl-38497972

RESUMEN

BACKGROUND: Corynebacterium (C.) sp. 22KM0430 related to C. oculi and isolated from a dog exhibited resistance to tetracycline, and its WGS analysis revealed a putative resistance gene on a 35 562-bp plasmid also harbouring the MLSB resistance gene erm(X). OBJECTIVES: To characterize the novel tetracycline resistance gene tet(65) and demonstrate its functionality by expression in C. glutamicum and Escherichia coli and plasmid curing of the host strain. METHODS: tet(65) was cloned with and without its repressor tetR(65) and expressed in C. glutamicum DSM20300 and E. coli DH5α. Plasmid was cured by non-selective passages. Minimal inhibitory concentrations (MICs) of tetracyclines were determined according to CLSI guidelines. Association of tet(65) with efflux was shown by the addition of reserpine to MIC assays. Phylogenetic position and transmembrane structure of Tet(65) were analysed using MEGA11 and DeepTMHMM. RESULTS: Tet(65) shows 73% amino acid identity with the closest related Tet(Z), contains 12 transmembrane domains and is structurally related to the Major Facilitator Superfamily. The tetracycline MICs decreased in the plasmid-cured strain and increased when tet(65) was expressed in C. glutamicum and in E. coli. The MICs of tetracycline decreased in the presence of reserpine indicating that tet(65) functions as an efflux pump. A GenBank search also identified tet(65) in C. diphtheriae and Brevibacterium (B.) casei and B. luteolum. CONCLUSIONS: A novel tetracycline efflux gene tet(65) was identified in a C. oculi related species and was also present in the human pathogen C. diphtheriae and in Brevibacterium species indicating broader potential for dissemination.


Asunto(s)
Antibacterianos , Corynebacterium , Escherichia coli , Pruebas de Sensibilidad Microbiana , Plásmidos , Resistencia a la Tetraciclina , Plásmidos/genética , Resistencia a la Tetraciclina/genética , Antibacterianos/farmacología , Escherichia coli/genética , Escherichia coli/efectos de los fármacos , Corynebacterium/genética , Corynebacterium/efectos de los fármacos , Animales , Farmacorresistencia Bacteriana Múltiple/genética , Filogenia , Perros , Tetraciclina/farmacología , Clonación Molecular , Infecciones por Corynebacterium/microbiología , Enfermedades de los Perros/microbiología
16.
J Antimicrob Chemother ; 79(5): 968-976, 2024 05 02.
Artículo en Inglés | MEDLINE | ID: mdl-38497937

RESUMEN

BACKGROUND: Evidence-based clinical susceptibility breakpoints have been lacking for antimicrobial agents used for diphtheria. OBJECTIVES: We aimed to evaluate broth microdilution and disc diffusion methods and create a dataset of MIC values and inhibition zone diameters (ZDs) from which breakpoints could be determined. METHODS: We included 400 recent clinical isolates equally distributed by species (Corynebacterium diphtheriae and Corynebacterium ulcerans) and by national surveillance programmes (France and Germany). Non-duplicate toxigenic and non-toxigenic isolates were chosen to enable the inclusion of a diversity of susceptibility levels for the 13 agents tested. Broth microdilution and disc diffusion, using EUCAST methodology for fastidious organisms, were used. RESULTS: The distributions of MIC and ZD values were largely in agreement among methods and countries. Breakpoints to allow categorization of WT isolates as susceptible, i.e. susceptible (S) or susceptible, increased exposure (I) were determined for 12 agents. The data supported a breakpoint for benzylpenicillin and amoxicillin of resistant (R) > 1 mg/L since WT isolates were inhibited by 1 mg/L or less. WT isolates were categorized as I (S ≤ 0.001 mg/L) for benzylpenicillin, emphasizing the need for increased exposure, and S (S ≤ 1 mg/L) for amoxicillin. Erythromycin breakpoints were set at S ≤ 0.06 mg/L and R > 0.06 mg/L. The corresponding ZD breakpoints were determined for all agents except amoxicillin, for which categorization was based on benzylpenicillin results. CONCLUSIONS: This work provided a large set of antimicrobial susceptibility data for C. diphtheriae and C. ulcerans, using a harmonized methodology. The dataset allowed EUCAST and experts in the diphtheria field to develop evidence-based breakpoints in January 2023.


Asunto(s)
Antibacterianos , Corynebacterium diphtheriae , Corynebacterium , Pruebas de Sensibilidad Microbiana , Pruebas de Sensibilidad Microbiana/métodos , Humanos , Corynebacterium/efectos de los fármacos , Corynebacterium/aislamiento & purificación , Antibacterianos/farmacología , Corynebacterium diphtheriae/efectos de los fármacos , Corynebacterium diphtheriae/aislamiento & purificación , Corynebacterium diphtheriae/genética , Alemania , Infecciones por Corynebacterium/microbiología , Difteria/microbiología , Francia
17.
Clin Lab ; 70(3)2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38469769

RESUMEN

BACKGROUND: The goal was to report a rare case of lymphadenitis caused by Corynebacterium tuberculostearicum, and the laboratory's coping approach in the isolation and identification of this rare pathogen to improve the understanding of the disease. METHODS: Lymph node biopsy was performed in a patient with suspected tuberculous lymphadenitis, and the biopsy tissue was isolated and cultured. RESULTS: The culture was Gram positive Corynebacterium, which was identified as Corynebacterium tuberculostearicum by microbial mass spectrometry and 16S rRNA gene sequencing. Antimicrobial susceptibility test showed that the drug was sensitive to daptomycin, doxycycline, gentamicin, linezolid, vancomycin, and meropenem, but resistant to ciprofloxacin, clindamycin, erythromycin, rifampicin, compound sulfamethoxazole, ceftriaxone, and cefepime. CONCLUSIONS: This is a case of Corynebacterium tuberculostearicum infection. Case reports of Corynebacterium tuberculostearicum infection are relatively rare in China. Through case study, we can provide help for laboratory isolation, identification, clinical diagnosis, and treatment.


Asunto(s)
Infecciones por Corynebacterium , Corynebacterium , Humanos , ARN Ribosómico 16S/genética , Corynebacterium/genética , Infecciones por Corynebacterium/diagnóstico , Infecciones por Corynebacterium/tratamiento farmacológico , Infecciones por Corynebacterium/microbiología , Vancomicina/uso terapéutico , Antibacterianos/uso terapéutico , Pruebas de Sensibilidad Microbiana
18.
PLoS One ; 19(2): e0298900, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38421980

RESUMEN

Rhodococcus equi pneumonia is an important cause of mortality in foals worldwide. Virulent equine isolates harbour an 80-85kb virulence plasmid encoding six virulence-associated proteins (Vaps). VapA, the main virulence factor of this intracellular pathogen, is known to be a cell surface protein that creates an intracellular niche for R. equi growth. In contrast, VapC, VapD and VapE are secreted into the intracellular milieu. Although these Vaps share very high degree of sequence identity in the C-terminal domain, the N-terminal domain (N-domain) of VapA is distinct. It has been proposed that this domain plays a role in VapA surface localization but no direct experimental data provides support to such hypothesis. In this work, we employed R. equi 103S harbouring an unmarked deletion of vapA (R. equi ΔvapA) as the genetic background to express C-terminal Strep-tagged Vap-derivatives integrated in the chromosome. The surface localization of these proteins was assessed by flow cytometry using the THE2122;-NWSHPQFEK Tag FITC-antibody. We show that VapA is the only cell surface Vap encoded in the virulence plasmid. We present compelling evidence for the role of the N-terminal domain of VapA on cell surface localization using fusion proteins in which the N-domain of VapD was exchanged with the N-terminus of VapA. Lastly, using an N-terminally Strep-tagged VapA, we found that the N-terminus of VapA is exposed to the extracellular environment. Given the lack of a lipobox in VapA and the exposure of the N-terminal Strep-tag, it is possible that VapA localization on the cell surface is mediated by interactions between the N-domain and components of the cell surface. We discuss the implications of this work on the light of the recent discovery that soluble recombinant VapA added to the extracellular medium functionally complement the loss of VapA.


Asunto(s)
Infecciones por Corynebacterium , Rhodococcus equi , Animales , Caballos , Virulencia/genética , Rhodococcus equi/genética , Membrana Celular , Proteínas de la Membrana
19.
PeerJ ; 12: e16751, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38406288

RESUMEN

Corynebacterium pseudotuberculosis is a gram-positive bacterium and is the etiologic agent of caseous lymphadenitis (CL) in small ruminants. This disease is characterized by the development of encapsulated granulomas in visceral and superficial lymph nodes, and its clinical treatment is refractory to antibiotic therapy. An important virulence factor of the Corynebacterium genus is the ability to produce biofilm; however, little is known about the characteristics of the biofilm produced by C. pseudotuberculosis and its resistance to antimicrobials. Silver nanoparticles (AgNPs) are considered as promising antimicrobial agents, and are known to have several advantages, such as a broad-spectrum activity, low resistance induction potential, and antibiofilm activity. Therefore, we evaluate herein the activity of AgNPs in C. pseudotuberculosis, through the determination of minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), antibiofilm activity, and visualization of AgNP-treated and AgNP-untreated biofilm through scanning electron microscopy. The AgNPs were able to completely inhibit bacterial growth and inactivate C. pseudotuberculosis at concentrations ranging from 0.08 to 0.312 mg/mL. The AgNPs reduced the formation of biofilm in reference strains and clinical isolates of C. pseudotuberculosis, with interference values greater than 80% at a concentration of 4 mg/mL, controlling the change between the planktonic and biofilm-associated forms, and preventing fixation and colonization. Scanning electron microscopy images showed a significant disruptive activity of AgNP on the consolidated biofilms. The results of this study demonstrate the potential of AgNPs as an effective therapeutic agent against CL.


Asunto(s)
Antiinfecciosos , Infecciones por Corynebacterium , Corynebacterium pseudotuberculosis , Linfadenitis , Nanopartículas del Metal , Humanos , Plata/farmacología , Nanopartículas del Metal/uso terapéutico , Antibacterianos/farmacología , Antiinfecciosos/farmacología , Infecciones por Corynebacterium/tratamiento farmacológico , Linfadenitis/tratamiento farmacológico , Biopelículas
20.
Indian J Med Microbiol ; 47: 100513, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-37931799

RESUMEN

Gram positive bacilli in the urine are usually dismissed as contaminants in urine specimens as these are commensal flora of skin and mucous membranes. Corynebacterium species were misidentified in the past due to complex biochemicals but the advent of modern diagnostics has made their identification quicker and accurate. Corynebacterium species have recently emerged as pathogens of nosocomial outbreak potential. C. striatum has been identified as opportunistic nosocomial pathogen causing various infections. We report first case of C. striatum as nosocomial urinary tract infection (UTI) pathogen in a child with bilateral renal disease. C. striatum causing UTI is very rarely reported.


Asunto(s)
Infecciones por Corynebacterium , Infección Hospitalaria , Infecciones Urinarias , Niño , Humanos , Infección Hospitalaria/microbiología , Infecciones por Corynebacterium/diagnóstico , Infecciones por Corynebacterium/tratamiento farmacológico , Infecciones por Corynebacterium/epidemiología , Antibacterianos/uso terapéutico , Corynebacterium , Infecciones Urinarias/diagnóstico , Infecciones Urinarias/tratamiento farmacológico , Infecciones Urinarias/microbiología
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