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Frontiers in Microbiology 2020Pathogenic non-spore forming bacteria enter a dormant state under stressful conditions, which likely allows them to acquire resistance to various antibiotics. This work...
Pathogenic non-spore forming bacteria enter a dormant state under stressful conditions, which likely allows them to acquire resistance to various antibiotics. This work revealed the efficient formation of dormant "non-culturable" (NC) cells in stationary phase upon gradual acidification of the growth medium. Such cells were unable to form colonies and existed in a prolonged stationary phase. At an early stage of dormancy (approximately 14 days post-inoculation), dormant cells are able for resuscitation in liquid medium. However, those stored for long time in dormant state needed addition of supernatant taking from active cultures for successful resuscitation. NC cells possessed low RNA synthesis and significant tolerance to antibiotics (rifampicin and vancomycin). They also accumulated free porphyrins, and 5-aminolevulinic acid addition enhanced free porphyrin accumulation which makes them potentially sensitive to photodynamic inactivation (PDI). PDI of dormant bacteria was accomplished by exposing cells to a 565 nm wavelength of light using a SOLIS-4C light-emitting diode for 60 min. This revealed that increased porphyrin concentrations were correlated with elevated PDI sensitivity. Results shown here demonstrate the potential utility of employing PDI to minimize levels of dormant, persistent corynebacteria and the dormancy model developed here may be useful for finding new drugs and techniques for combatting persistent corynebacteria.
PubMed: 33391228
DOI: 10.3389/fmicb.2020.605899 -
Emerging Infectious Diseases Dec 2021To determine differences in clinical characteristics of patients with bacteremia caused by , , and other species of , we retrospectively reviewed medical records of... (Review)
Review
To determine differences in clinical characteristics of patients with bacteremia caused by , , and other species of , we retrospectively reviewed medical records of patients in Japan who had bacteremia during January 2014–May 2020. Of the 115 records evaluated, 60 (52%) were cases of true bacteremia and 55 (48%) were cases of contamination. Proportions of true bacteremia cases caused by (70%) and by (71%) were significantly higher than those caused by other species of (9%). These 2 organisms were commonly detected in blood cultures of patients with hematologic malignancies and neutropenia. The mortality rates at 90 days were 34% (), 30% (), and 0 (other species). Given the high mortality rates, assessing true bacteremia when or is detected in blood cultures, especially in patients with hematologic malignancy, is warranted.
Topics: Anti-Bacterial Agents; Bacteremia; Corynebacterium; Corynebacterium Infections; Humans; Japan
PubMed: 34812137
DOI: 10.3201/eid2712.210473 -
Antibiotics (Basel, Switzerland) Jul 2020is a commensal bacterium that colonizes human skin, and it is part of the normal bacterial flora. In non-risk subjects, it can be the cause of bad body smell due to the...
is a commensal bacterium that colonizes human skin, and it is part of the normal bacterial flora. In non-risk subjects, it can be the cause of bad body smell due to the generation of volatile odorous metabolites, especially in the wet parts of the body that this bacterium often colonizes (i.e., groin and axillary regions). Importantly, in the last few decades, there have been increasing cases of serious infections provoked by this bacterium, especially in immunocompromised or hospitalized patients who have undergone installation of prostheses or catheters. The ease in developing resistance to commonly-used antibiotics (i.e., glycopeptides) has made the search for new antimicrobial compounds of clinical importance. Here, for the first time, we characterize the antimicrobial activity of some selected frog skin-derived antimicrobial peptides (AMPs) against by determining their minimum inhibitory and bactericidal concentrations (MIC and MBC) by a microdilution method. The results highlight esculentin-1b(1-18) [Esc(1-18)] and esculentin-1a(1-21) [Esc(1-21)] as the most active AMPs with MIC and MBC of 4-8 and 0.125-0.25 µM, respectively, along with a non-toxic profile after a short- and long-term (40 min and 24 h) treatment of mammalian cells. Overall, these findings indicate the high potentiality of Esc(1-18) and Esc(1-21) as (i) alternative antimicrobials against infections and/or as (ii) additives in cosmetic products (creams, deodorants) to reduce the production of bad body odor.
PubMed: 32722535
DOI: 10.3390/antibiotics9080448 -
Cureus Sep 2021is a rare cause of prosthetic joint infections (PJIs) and infection after fracture fixation (IAFF). We present a case of a patient who developed associated IAFF three...
is a rare cause of prosthetic joint infections (PJIs) and infection after fracture fixation (IAFF). We present a case of a patient who developed associated IAFF three weeks after his fracture fixation. Due to its slow-growing nature, surgical cultures remained negative after 72 hours and grew only on day 5. We highlight that physicians should have -associated infection in their differential in such cases, especially when the cultures remain negative after 72 hours. We also review the literature of PJI and implant-associated infection with and discuss the antibiotic resistance patterns and some microbiological considerations associated with
PubMed: 34650854
DOI: 10.7759/cureus.17676 -
Open Forum Infectious Diseases Jul 2022periprosthetic joint infection (PJI) is a poorly described infectious syndrome. Prior studies included cases of polymicrobial infections. This series describes the...
BACKGROUND
periprosthetic joint infection (PJI) is a poorly described infectious syndrome. Prior studies included cases of polymicrobial infections. This series describes the clinical characteristics, management, and outcomes of monomicrobial PJI.
METHODS
We queried the Mayo Clinic Total Joint Registry for cases of monomicrobial knee and hip PJI in adults (age ≥18 years) between 2010 and 2019.
RESULTS
A total of 20 (1%) out of 2067 PJI cases met our inclusion criteria. Most were males (55%), and the median age was 64 years. Seventy percent had chronic symptoms (>4 weeks). PJI was delayed to late (>3 months postimplantation) in 90%. Three species were identified: (70%), (20%), and (10%). All tested isolates were susceptible to vancomycin (100%) and linezolid (100%), and most had a minimum inhibitory concentration ≤0.06 mcg/mL to daptomycin (75%). Other agents were less reliable, with high resistance to oral agents commonly used for suppression. Nineteen patients were treated: 37% debridement and implant retention (DAIR), 47% 2-stage exchange, and 16% resection without reimplantation. Of these, failure occurred in 29%, 11%, and 0%, respectively.
CONCLUSIONS
PJIs pose a therapeutic challenge due to limited antimicrobial armamentarium and undefined optimal surgical intervention. Vancomycin and linezolid remain the most reliable agents for treatment. DAIR may be attempted for acute PJI, but verification of durable chronic suppression options will be critical for this approach.
PubMed: 35873283
DOI: 10.1093/ofid/ofac193 -
Cureus Jun 2020is a multidrug-resistant gram-positive bacterium of the human skin flora and one of the most clinically important nondiphtherial corynebacteria in the acute care...
is a multidrug-resistant gram-positive bacterium of the human skin flora and one of the most clinically important nondiphtherial corynebacteria in the acute care setting. can cause different forms of infections, especially in immunocompromised patients with underlying risk factors and comorbidities. was initially described in 1976 as a highly resistant coryneform bacteria causing severe sepsis in patients with hematologic malignancies and profound neutropenia. infection has also been reported in the setting of endocarditis, septicemia, meningitis, pneumonia, and soft tissue infections. Management of disseminated infection in immunocompromised cancer patients can be challenging due to its high virulence and rapid skin colonization. We present two cases of disseminated infection in patients with acute myelogenous leukemia (AML) and underlying comorbidities. Both patients presented with neutropenic fever resistant to initial standard empiric antibiotic therapy.
PubMed: 32714702
DOI: 10.7759/cureus.8764 -
European Heart Journal. Case Reports Dec 2020The Modified Duke criteria is an important structured schematic for the diagnosis of infective endocarditis (IE). is a rare cause of IE that is often resistant to...
BACKGROUND
The Modified Duke criteria is an important structured schematic for the diagnosis of infective endocarditis (IE). is a rare cause of IE that is often resistant to standard IE anti-microbials. We present a case of IE, fulfilling the Modified Duke pathological criteria.
CASE SUMMARY
A 50-year-old male presented with left leg peripheral vascular disease with septic changes requiring amputation. Routine echocardiography post-amputation demonstrated severe aortic valve regurgitation with vegetations that required valve replacement. Two initial blood cultures from a single venepuncture showed which was treated with penicillin G prior to surgery. Subsequent aortic valve tissue cultured with suggestive IE histological valvular changes and was successfully treated on a prolonged course of vancomycin.
DISCUSSION
This is the first IE case diagnosed on heart valvular tissue culture and highlights the importance for the fulfilment of the Modified Duke criteria in diagnosing left-sided IE. Mixed infection IE is rare, and this case possibly represents an unmasking of resistant IE following initial treatment of penicillin G.
PubMed: 33447720
DOI: 10.1093/ehjcr/ytaa365 -
Open Forum Infectious Diseases Mar 2021species are often dismissed as contaminants in blood cultures, but they can also cause infective endocarditis (IE), which is a severe condition. Antibiotic resistance...
BACKGROUND
species are often dismissed as contaminants in blood cultures, but they can also cause infective endocarditis (IE), which is a severe condition. Antibiotic resistance of corynebacteria is increasing making treatment challenging. Reports on IE caused by species are scarce and more knowledge is needed.
METHODS
Cases of IE caused by species were identified through the Swedish Registry of Infective Endocarditis. Isolates were collected for species redetermination by matrix-assisted laser desorption ionization-time of flight and for antibiotic susceptibility testing using Etests.
RESULTS
Thirty episodes of IE due to species were identified between 2008 and 2017. The median age of patients was 71 years (interquartile range, 60-76) and 77% were male. (n = 11) was the most common IE causing pathogen followed by (n = 5). Surgery was performed in 50% and in-hospital mortality rate was 13%. Patients with IE caused by species were significantly more likely to have prosthetic valve endocarditis (70%), compared with patients with IE due to or non-beta-hemolytic streptococci (14% and 26%, respectively) ( < .0001). Vancomycin was active towards all isolates, whereas resistance towards penicillin G was common.
CONCLUSIONS
species cause IE, where prosthetic valves are mainly affected and surgery is often performed. is an important causative agent of IE within the genus. Antibiotic resistance of corynebacteria is relatively common but resistance towards vancomycin could not be detected in vitro.
PubMed: 33738317
DOI: 10.1093/ofid/ofab055 -
Infection and Drug Resistance 2022To explore the perioperative prophylactic medication, identification of Causative pathogen and the treatment strategy of post-craniotomy intracranial infection (PCII)...
OBJECTIVE
To explore the perioperative prophylactic medication, identification of Causative pathogen and the treatment strategy of post-craniotomy intracranial infection (PCII) caused by Corynebacterium.
PATIENTS AND METHODS
A 47-year-old overweight male patient with hypertension, diabetes, cerebral hemorrhage and recalcitrant syphilis was clinically diagnosed with PCII based on cerebrospinal fluid (CSF) routine examination (RT), biochemical test (BT), neuroimaging CT and MRI scans, bacterial culture and identification of CSF and clinical manifestations. The risk factors of PCII and perioperative antibiotic prophylaxis were analyzed based on some reviews. The identification of the Corynebacterium Jeikeium (C. Jeikeium) and Corynebacterium simulans (C. simulans) was confirmed by CSF bacterial culture, antibiotics sensitivity in vitro and Metagenomic next-generation sequencing (mNGS) of pathogenic microorganisms, respectively. In addition, individualized therapy schemes were modified according to antimicrobial susceptibility of pathogens and mNGS of pathogenic microorganisms combined with the pathologic and physiological conditions of patients. The efficacy was evaluated depending on the changes in patients' body temperature, clinical manifestation, CSF RT, BT, and other infection-related indicators.
RESULTS
The patient recovered after 5 weeks of individualized comprehensive treatment and was discharged home, no recurrence had been observed for three months.
CONCLUSION
This is likely the first reported case of chronic PCII caused by two species of Corynebacterium simultaneously in high risk patient. The PCII can not be prevented by the perioperative antibiotic prophylaxis recommended by the guidelines, prophylaxis need to be individualized based on the risk of infection and the colonization status of the patient. Causative pathogens can be identified by CSF culture and mNGS of pathogenic microorganisms. A judicious antimicrobial therapy plan should take into account not only the in vitro antimicrobial susceptibility, but also the penetration of the antimicrobial agent into the cerebrospinal fluid. It was an excellent choice to combine intrathecal vancomycin with intravenous linezolid to treat PCII resulted from Corynebacterium.
PubMed: 36411755
DOI: 10.2147/IDR.S368857 -
Medeniyet Medical Journal 2021Non-diphtheriae Corynebacterium strains have been recognized as important pathogens after decades of confusion regarding their microbiological classification and...
OBJECTIVE
Non-diphtheriae Corynebacterium strains have been recognized as important pathogens after decades of confusion regarding their microbiological classification and clinical significance. The aim of this study was to identify non-diphtheriae Corynebacterium strains and the prevalence of biofilm formation and antimicrobial resistance.
METHOD
In total, 126 non-diphtheriae Corynebacterium strains were isolated from blood cultures of inpatients with bacteremia in our hospital between January 2015 and January 2020. Blood cultures were analyzed with the Bactec-9120 system. Strains were identified using MALDI-TOF MS (Bruker Daltonics, Germany). Antimicrobial susceptibilities were determined using the Kirby-Bauer disk diffusion method on a Mueller-Hinton agar and evaluated according to EUCAST standards. Biofilm formation was assessed with the Congo Red Agar method.
RESULTS
Corynebacterium striatum and Corynebacterium matruchotii were the most prevalent with 29 and 26 isolates, respectively. Biofilm production was detected in 62.06% (18/29) of C. striatum, in 53.8% (14/26) of C. matruchotii, in 50% (9/18) of Corynebacterium afermentans, 50% (6/12) of Corynebacterium amycolatum, and in 46% (7/15) of Corynebacterium jeikeium strains. Among the five most prevalent strains, we found a high biofilm rate of 54%. The resistance rates to penicillin, clindamycin, ciprofloxacin, rifampicin, tetracycline, and gentamicin were 91.2%, 87.3%, 79.3%, 56.3%, 45.2%, and 39.6%, respectively. All 126 strains were susceptible to vancomycin and linezolid.
CONCLUSION
Non-diphtheriae Corynebacterium strains isolated from blood cultures of hospitalized patients with bacteremia may have multidrug resistance and the ability to produce biofilm. These results emphasize the importance of identifying strains and determining their antimicrobial susceptibility and biofilm production potential.
PubMed: 34239764
DOI: 10.5222/MMJ.2021.60252