Antimicrobial susceptibilities of Corynebacterium species and other non-spore-forming gram-positive bacilli to 18 antimicrobial agents

Exploration of the role of the penicillin binding protein 2c (Pbp2c) in inducible β-lactam resistance in Corynebacteriaceae

Six genes encoding putative high molecular weight penicillin-binding proteins (Pbp) are present in the genome of the β-lactam-resistant strain Corynebacterium jeikeium K411. In this study, we show that pbp2c, one of these six genes, is present in resistant strains of Corynebacteriaceae but absent from sensitive strains. The molecular study of the pbp2c locus from C. jeikeium and its heterologous expression in Corynebacterium glutamicum allowed us to show that Pbp2c confers high levels of β-lactam resistance to the host and is under the control of a β-lactam-induced regulatory system encoded by two adjacent genes, jk0410 and jk0411. The detection of this inducible resistance may require up to 48 h of incubation, particularly in Corynebacterium amycolatum. Finally, the Pbp2c-expressing strains studied were resistant to all the β-lactam antibiotics tested, including carbapenems, ceftaroline, and ceftobiprole.

Novel Organism Verification and Analysis (NOVA) study: identification of 35 clinical isolates representing potentially novel bacterial taxa using a pipeline based on whole genome sequencing

BACKGROUND

Reliable species identification of cultured isolates is essential in clinical bacteriology. We established a new study algorithm named NOVA - Novel Organism Verification and Analysis to systematically analyze bacterial isolates that cannot be characterized by conventional identification procedures MALDI-TOF MS and partial 16 S rRNA gene sequencing using Whole Genome Sequencing (WGS).

RESULTS

We identified a total of 35 bacterial strains that represent potentially novel species. Corynebacterium sp. (n = 6) and Schaalia sp. (n = 5) were the predominant genera. Two strains each were identified within the genera Anaerococcus, Clostridium, Desulfovibrio, and Peptoniphilus, and one new species was detected within Citrobacter, Dermabacter, Helcococcus, Lancefieldella, Neisseria, Ochrobactrum (Brucella), Paenibacillus, Pantoea, Porphyromonas, Pseudoclavibacter, Pseudomonas, Psychrobacter, Pusillimonas, Rothia, Sneathia, and Tessaracoccus. Twenty-seven of 35 strains were isolated from deep tissue specimens or blood cultures. Seven out of 35 isolated strains identified were clinically relevant. In addition, 26 bacterial strains that could only be identified at the species level using WGS analysis, were mainly organisms that have been identified/classified very recently.

CONCLUSION

Our new algorithm proved to be a powerful tool for detection and identification of novel bacterial organisms. Publicly available clinical and genomic data may help to better understand their clinical and ecological role. Our identification of 35 novel strains, 7 of which appear to be clinically relevant, shows the wide range of undescribed pathogens yet to define.

Hard-to-heal peripheral wounds infected with Corynebacterium striatum: a prospective study

OBJECTIVE

To investigate Corynebacterium striatum as a nosocomial pathogen infecting hard-to-heal peripheral wounds, such as skin wounds, soft tissue abscesses and osteomyelitis. As of 2023, the medical community were alerted against the risk of emerging systemic and central infections; on the other hand literature on peripheral cutaneous regions is still scarce.

METHOD

In this study, two groups of patients with similar lesions which were infected were compared: one group with the presence of the coryneform rod, the other without.

RESULTS

In total, Corynebacterium striatum was cultured from 62 patients and 131 samples. Corynebacterium striatum infection correlated well with the presence of: foot ulcer; venous leg ulcer; altered ambulation and/or altered foot loading; peripheral vascular and arterial disease; hospitalisation; malignancy; spinal cord injury; and recent administration of antibiotics (p<0.05 for all associations). Patients with Corynebacterium striatum had a lower overall survival rate compared to patients in the non-Corynebacterium striatum group (28.6 versus 31.6 months, respectively; p=0.0285). Multivariate analysis revealed that Corynebacterium striatum infection was an independent factor for poor prognosis (p<0.0001).

CONCLUSION

In view of the findings of our study, Corynebacterium striatum appears to be an important opportunistic pathogen infecting peripheral tissues and complicating wound healing. Given its numerous and worrying virulence factors (such as multidrug resistance and biofilm production), particular attention should be given to this pathogen by professional wound care providers in nosocomial and outpatient environments.

Intra-soft tissue and intramedullary antibiotic perfusion in combination with negative pressure wound therapy

OBJECTIVE

Intra-soft tissue and intramedullary antibiotic perfusion (iSAP and iMAP), which combine continuous administration of antibiotic solution to the wound and negative pressure wound therapy (NPWT), have been reported to be a useful management approach for hard-to-heal ulcers in the field of orthopaedic surgery. We report the efficacy of this treatment and discuss the key points.

METHOD

The recipients of this treatment had contaminated fresh severe trauma with a high risk of infection, or hard-to-heal ulcers which were expected to be difficult to manage with conventional NPWT alone. Continuous administration of 1200µg/ml of gentamicin (GM) solution to the wound was performed along with NPWT. The GM solution was administered subcutaneously using a small catheter for iSAP, while intramedullary administration used a bone marrow needle for iMAP.

RESULTS

iSAP was employed in all 10 patients who took part, and iMAP in three of these patients. The average treatment time was 13.6 days with iSAP and 9.3 days with iMAP. The mean serum GM level during the therapy was 1.02µg/ml. Moderate GM-induced acute kidney injury was suspected in one case, but resolved spontaneously after GM administration was stopped. Favourable wound bed preparation was achieved in all cases without recurrence of infection.

CONCLUSION

Combination with continuous suction by NPWT is able to keep the local concentration of antibiotic above the minimum inhibitory concentration of biofilm-coated bacteria within the wound. We have referred to this treatment as continuous local antibiotic perfusion. Further investigation of local pharmacodynamics in the wound and side-effects of this treatment are warranted.

Phylogenetic analyses of antimicrobial resistant Corynebacterium striatum strains isolated from a nosocomial outbreak in a tertiary hospital in China

Corynebacterium striatum is an emerging, multidrug-resistant pathogen that frequently causes nosocomial infections worldwide. This study aimed to investigate phylogenetic relationship and presence of genes responsible for antimicrobial resistance among C. striatum strains associated with an outbreak at the Shanxi Bethune Hospital, China, in 2021. Fecal samples were collected from 65 patients with C. striatum infection at Shanxi Bethune Hospital between February 12, 2021 and April 12, 2021. C. striatum isolates were identified by 16S rRNA and rpoB gene sequencing. E-test strips were used to examine the antimicrobial susceptibility of the isolates. Whole-genome sequencing and bioinformatics analysis were employed to assess the genomic features and identify antimicrobial resistance genes of the isolates. Crystal violet staining was conducted to determine the ability of biofilm formation of each isolate. A total of 64 C. striatum isolates were identified and categorized into 4 clades based on single nucleotide polymorphisms. All isolates were resistant to penicillin, meropenem, ceftriaxone, and ciprofloxacin but susceptible to vancomycin and linezolid. Most isolates were also resistant to tetracycline, clindamycin, and erythromycin, with susceptibility rates of 10.77, 4.62, and 7.69%, respectively. Genomic analysis revealed 14 antimicrobial resistance genes in the isolates, including tetW, ermX, and sul1. Crystal violet staining showed that all isolates formed biofilms on the abiotic surface. Four clades of multidrug-resistant C. striatum spread in our hospitals possibly due to the acquisition of antimicrobial resistance genes.

Multidrug-resistant toxigenic Corynebacterium diphtheriae sublineage 453 with two novel resistance genomic islands

Antimicrobial therapy is important for case management of diphtheria, but knowledge on the emergence of multidrug-resistance in Corynebacterium diphtheriae is scarce. We report on the genomic features of two multidrug-resistant toxigenic isolates sampled from wounds in France 3 years apart. Both isolates were resistant to spiramycin, clindamycin, tetracycline, kanamycin and trimethoprim-sulfamethoxazole. Genes ermX, cmx, aph(3')-Ib, aph(6)-Id, aph(3')-Ic, aadA1, dfrA15, sul1, cmlA, cmlR and tet(33) were clustered in two genomic islands, one consisting of two transposons and one integron, the other being flanked by two IS6100 insertion sequences. One isolate additionally presented mutations in gyrA and rpoB and was resistant to ciprofloxacin and rifampicin. Both isolates belonged to sublineage 453 (SL453), together with 25 isolates from 11 other countries (https://bigsdb.pasteur.fr/diphtheria/). SL453 is a cosmopolitan toxigenic sublineage of C. diphtheriae, a subset of which acquired multidrug resistance. Even though penicillin, amoxicillin and erythromycin, recommended as the first line in the treatment of diphtheria, remain active, surveillance of diphtheria should consider the risk of dissemination of multidrug-resistant strains and their genetic elements.

External Ear Canal Evaluation in Dogs with Chronic Suppurative Otitis Externa: Comparison of Direct Cytology, Bacterial Culture and 16S Amplicon Profiling

A discrepancy between cytology and bacterial culture methods is sometimes observed in canine otitis externa. The objective of this study was to compare results from cytology, bacterial culture and 16S amplicon profiling. Twenty samples from 16 dogs with chronic suppurative otitis externa were collected. A direct cytological evaluation was carried out during the consultations. Aerobic bacterial culture and susceptibility were performed by an external laboratory used in routine practice. For 16S amplicon profiling, DNA was extracted and the hypervariable segment V1−V3 of the 16S rDNA was amplified and then sequenced with a MiSeq Illumina sequence carried out by the Mothur software using the SILVA database. A good correlation between cytology and bacterial culture was observed in 60% of the samples. Some bacterial species revealed by bacterial culture were present with low relative abundance (<10%) in 16S amplicon profiling. Some bacterial species revealed by the 16S amplicon profiling analysis were not identified with culture; most of the time, the offending species was a Corynebacterium. To conclude, a careful interpretation of the results of bacterial culture should be made and always be in agreement with the cytology. The 16S amplicon profiling method appears to be a more sensitive method for detecting strains present in suppurative otitis but does not provide information on bacterial susceptibility.

Clinical Characteristics of Corynebacterium Bacteremia Caused by Different Species, Japan, 2014-2020

Corynebacterium bacteremia is most commonly caused by C. striatum or C. jeikeium.

To determine differences in clinical characteristics of patients with bacteremia caused by Corynebacterium striatum, C. jeikeium, and other species of Corynebacterium, we retrospectively reviewed medical records of patients in Japan who had Corynebacterium 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 C. striatum (70%) and by C. jeikeium (71%) were significantly higher than those caused by other species of Corynebacterium (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% (C. striatum), 30% (C. jeikeium), and 0 (other species). Given the high mortality rates, assessing true bacteremia when C. striatum or C. jeikeium is detected in blood cultures, especially in patients with hematologic malignancy, is warranted.

Detection of Corynebacterium kroppenstedtii in Granulomatous Lobular Mastitis Using Real-Time Polymerase Chain Reaction and Sanger Sequencing on Formalin-Fixed, Paraffin-Embedded Tissues

CONTEXT.—

Associations between granulomatous lobular mastitis (GLM) and Corynebacterium kroppenstedtii have been reported since 2002, but large scale studies to assess the actual prevalence of this bacterium in GLM have not been performed.

OBJECTIVE.—

To assess the prevalence of C kroppenstedtii in GLM using real-time polymerase chain reaction and Sanger sequencing.

DESIGN.—

We analyzed formalin-fixed, paraffin-embedded tissues from 67 cases of GLM by sequential DNA amplification and sequencing to assess the rate of C kroppenstedtii detection in GLM. A retrospective analysis including patient demographics, history of pregnancy and lactation, clinical signs and symptoms, radiographic findings, histologic pattern, Gram stain results, and microbial cultures was performed on 67 cases of GLM. In addition, 10 cases of nongranulomatous breast abscess were included as controls.

RESULTS.—

C kroppenstedtii 16S rRNA SYBR real-time polymerase chain reaction was positive on formalin-fixed, paraffin-embedded tissues from 46 of 67 (68.7%) GLM cases, while all control cases were negative. Among the positive cases, the majority showed features of cystic neutrophilic granulomatous mastitis.

CONCLUSIONS.—

C kroppenstedtii was highly prevalent in GLM cases and was not found to be associated with nongranulomatous breast abscess in our study (P < .001).

Corynebacterium Jeikeium Endocarditis: A Review of the Literature

Corynebacterium jeikeium is a gram-positive, aerobic, pleomorphic, nonspore forming bacillus, commonly present on the skin surface. Infective endocarditis secondary to C. jeikeium most commonly affects left-sided heart valves and has a higher likelihood to require valve replacement compared to other Corynebacterium endocarditis. C. jeikeium endocarditis is extremely difficult to treat as it is characteristically resistant to penicillin, cephalosporins and aminoglycosides, and sensitivity to quinolones, macrolides, tetracyclines and rifampin is variable. Despite treatment, mortality rates as high as 33% have been reported. We hereby review the literature regarding the epidemiology, diagnosis and treatment of this deadly microorganism.

Infective Endocarditis Due to Corynebacterium Species: Clinical Features and Antibiotic Resistance

Background

Corynebacterium 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 Corynebacterium species are scarce and more knowledge is needed.

Methods

Cases of IE caused by Corynebacterium 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 Corynebacterium species were identified between 2008 and 2017. The median age of patients was 71 years (interquartile range, 60–76) and 77% were male. Corynebacterium striatum (n = 11) was the most common IE causing pathogen followed by Corynebacterium jeikeium (n = 5). Surgery was performed in 50% and in-hospital mortality rate was 13%. Patients with IE caused by Corynebacterium species were significantly more likely to have prosthetic valve endocarditis (70%), compared with patients with IE due to Staphylococcus aureus or non-beta-hemolytic streptococci (14% and 26%, respectively) (P < .0001). Vancomycin was active towards all Corynebacterium isolates, whereas resistance towards penicillin G was common.

Conclusions

Corynebacterium species cause IE, where prosthetic valves are mainly affected and surgery is often performed. Corynebacterium striatum 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.

Current Evidence for Corynebacterium on the Ocular Surface

Corynebacterium species are commonly found in the conjunctiva of healthy adults and are recognized as non-pathogenic bacteria. In recent years, however, Corynebacterium species have been reported to be potentially pathogenic in various tissues. We investigated Corynebacterium species on the ocular surface and reviewed various species of Corynebacterium in terms of their antimicrobial susceptibility and the underlying molecular resistance mechanisms. We identified a risk for Corynebacterium-related ocular infections in patients with poor immunity, such as patients with diabetes or long-term users of topical steroids, and in those with corneal epithelial damage due to trauma, contact lens wear, lagophthalmos, and trichiasis. The predominant strain in the conjunctiva was C. macginleyi, and the species associated with keratitis and conjunctivitis were C. macginleyi, C. propinquum, C. mastitidis, C. pseudodiphtheriticum, C. accolens, C. striatum, C. xerosis, and C. bovis. Overall, Corynebacterium species present on the ocular surface were resistant to quinolones, whereas those in the nasal cavity were more susceptible. The prevalence of fluoroquinolone-resistant Corynebacterium has not changed in the past 10 years; however, Corynebacterium species remain susceptible to third-generation cephems. In conclusion, the use of third-generation cephems should be a reasonable and pragmatic approach for treatment of ocular infections caused by Corynebacterium species.

Encrusted Uropathy: A Comprehensive Overview-To the Bottom of the Crust

Encrusted uropathy is a rare subacute to chronic inflammatory disorder caused by infection with urease-producing bacteria, mainly Corynebacterium urealyticum. The disorder is characterized by urothelial deposition of struvite and carbonated apatite, resulting in encrustations and ulceronecrotic inflammation of the urothelium and surrounding tissues. Most commonly, encrusted uropathy is encountered in patients with predisposing conditions. The disease remains underdiagnosed. High urinary pH and negative conventional urine cultures should raise suspicion of the diagnosis. Prognosis is dependent on timely diagnosis and treatment installment, which consists of urological removal of encrustations in combination with urinary acidification and long-term antibiotic therapy.

Corynebacterium jeikeium Dormant Cell Formation and Photodynamic Inactivation

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) Corynebacterium jeikeium 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 C. jeikeium 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 C. jeikeium dormancy model developed here may be useful for finding new drugs and techniques for combatting persistent corynebacteria.

Clinical relevance and impact of Corynebacterium isolation in lower respiratory tract of critically ill patients requiring mechanical ventilation

Purpose

Corynebacterium spp. (C. spp.) is commonly considered as a contaminant in respiratory specimens. No study has ever focused on its clinical relevance in the lower respiratory tract of patients admitted to the intensive care unit (ICU) and requiring mechanical ventilation. The aims were to describe the characteristics of ICU patients with a C. spp. positive deep respiratory specimen, to investigate the impact of C. spp. on the occurrence of pneumonia, and to evaluate the outcomes of these pneumonia.

Methods

We retrospectively included all adult patients admitted to ICU in a 1000-bed University Hospital (2007–2017) who had a C. spp. positive lower respiratory tract specimen at a significant quantitative level. We used clinical, radiological, and microbiological criteria to classify the likelihood of such pneumonia.

Results

Among the 31 patients included, acute respiratory failure and postoperative care after major surgery were the main reasons of admission. SAPS II was 47 [34–60]. C. spp. pneumonia was considered as probable, possible and unlikely in 10, 14, and 7 patients, respectively. Fifty-two and 94% of C. spp. strains were sensitive to amoxicillin, and vancomycin/linezolid, respectively. Seventeen patients had a complete course of antibiotic against C. spp. The overall ICU mortality was 58%.

Conclusion

Corynebacterium spp seems to be responsible for authentic pneumonia in mechanically ventilated patients. It should be considered as clinically relevant when predominantly present in respiratory specimen from patients suspected with pneumonia in ICU, and empirically treated.

Corynebacterium rouxii sp. nov., a novel member of the diphtheriae species complex

A group of six clinical isolates previously identified as Corynebacterium diphtheriae biovar Belfanti, isolated from human cutaneous or peritoneum infections and from one dog, were characterized by genomic sequencing, biochemical analysis and MALDI-TOF mass spectrometry. The six isolates were negative for the diphtheria toxin gene. Phylogenetic analyses showed that the six isolates (including FRC0190^T) are clearly demarcated from C. diphtheriae, Corynebacterium belfantii, Corynebacterium ulcerans and Corynebacterium pseudotuberculosis. The average nucleotide identity of FRC0190^T with C. diphtheriae NCTC11397^T was 92.6%, and was 91.8% with C. belfantii FRC0043^T. C. diphtheriae subsp. lausannense strain CHUV2995^T appeared to be a later heterotypic synonym of C. belfantii (ANI, 99.3%). Phenotyping data revealed an atypical negative or heterogeneous intermediate maltose fermentation reaction for the six isolates. MALDI-TOF mass spectrometry differentiated the new group from the other Corynebacterium taxa by the presence of specific spectral peaks. rpoB sequences showed identity to atypical, maltose-negative C. diphtheriae biovar Belfanti isolates previously described from two cats in the USA. We propose the name Corynebacterium rouxii sp. nov. for the novel group, with FRC0190^T (= CIP 111752^T = DSM 110354^T) as type strain.

Antimicrobial Susceptibility Testing for Corynebacterium Species Isolated from Clinical Samples in Romania

Antimicrobial resistance is one of the most important public health issues. Besides classical multidrug resistance species associated with medical care involved in superficial or invasive infections, there are strains less commonly associated with hospital or outpatient setting’s infections. Non-diphtheria Corynebacterium spp. could produce infections in patients with or without immune-compromised status. The aim of our study was to determine the susceptibility to antimicrobial agents to Corynebacterium spp. from clinical samples collected from Romanian hospitalized individuals and outpatients. Twenty Corynebacterium strains were isolated and identified as Corynebacterium striatum (n = 7), Corynebacterium amycolatum (n = 7), C. urealyticum (n = 3), Corynebacterium afermentans (n = 2), and Corynebacterium pseudodiphtheriticum (n = 1). All isolates have been tested for antibiotic susceptibility by standardized disc diffusion method and minimal inhibitory concentration (MIC) tests. Seventeen isolates demonstrated multidrug resistance phenotypes. The molecular support responsible for high resistance to quinolones for ten of these strains was determined by the detection of point mutation in the gene sequence gyrA.

Antibacterial Activity of Conifer Green Needle Complex Against Corynebacteria

Traditionally, preservatives have been used in cosmetic products to minimize bacterial contamination. Some opportunistic Corynebacterium spp. have become resistant to these preservatives and other alternatives are required. A potential candidate is Conifer Green Needle Complex (CGNC), a pharmaceutical-grade complex substance from the green verdure of Pinus sylvestris and Picea abies with antibacterial, antimycotic, and antitrichomonal activity. The susceptibility of Corynebacterium xerosis and Corynebacterium flavescens to CGNC (3.5, 7, 15, 30, 60, 125, 250, and 500 mg/mL) was evaluated using broth dilution and agar methods. The antibacterial effect of CGNC was also evaluated after exposure for 30 minutes and 1, 3, and 24 hours at concentrations of 0, 3.5, 7, 30, 125, and 500 mg/mL. Corynebacteria xerosis was inhibited when exposed to low levels of CGNC (1560 mg/mL), whereas an antibacterial effect on C. flavescens was observed at slightly higher levels (60 and 125 mg/mL). CGNC also inhibited the growth of C. xerosis and C. flavescens at various incubation time points. The most prominent effect was observed after 24 hours where all growth was inhibited at all concentrations. However, CGNC inhibited or decreased the growth of Corynebacterium spp. even at lower exposure times. The results obtained in this study demonstrated that CGNC is an effective bactericidal agent against C. xerosis and C. flavescens isolated from clinical samples and may have potential as an alternative to preservatives currently used in cosmetic products.

Diphtheria

Diphtheria is a potentially fatal infection mostly caused by toxigenic Corynebacterium diphtheriae strains and occasionally by toxigenic C. ulcerans and C. pseudotuberculosis strains. Diphtheria is generally an acute respiratory infection, characterized by the formation of a pseudomembrane in the throat, but cutaneous infections are possible. Systemic effects, such as myocarditis and neuropathy, which are associated with increased fatality risk, are due to diphtheria toxin, an exotoxin produced by the pathogen that inhibits protein synthesis and causes cell death. Clinical diagnosis is confirmed by the isolation and identification of the causative Corynebacterium spp., usually by bacterial culture followed by enzymatic and toxin detection tests. Diphtheria can be treated with the timely administration of diphtheria antitoxin and antimicrobial therapy. Although effective vaccines are available, this disease has the potential to re-emerge in countries where the recommended vaccination programmes are not sustained, and increasing proportions of adults are becoming susceptible to diphtheria. Thousands of diphtheria cases are still reported annually from several countries in Asia and Africa, along with many outbreaks. Changes in the epidemiology of diphtheria have been reported worldwide. The prevalence of toxigenic Corynebacterium spp. highlights the need for proper clinical and epidemiological investigations to quickly identify and treat affected individuals, along with public health measures to prevent and contain the spread of this disease.

A case of recurrent Corynebacterium jeikeium endocarditis: Unanswered questions for the treatment of chronic endovascular infections

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Many factors confer increased risk of recurrent endocarditis.

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Often many of these factors co-exist in the same host.

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There is always the risk of residual infected endocardial tissue despite repeated debridement.

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The traditional 4–6 week parenteral course in endocarditis accounts for bacterial tolerance and antimicrobial resistance.

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The decision on antimicrobial therapy and duration are supported by evidence but should be individualized.

A 53-year-old woman with end-stage renal impairment on hemodialysis was evaluated for recurrent episodes of Corynebacterium jeikeium bacteremia and endocarditis. Her recurrences occurred despite surgical debridement and extended courses of culture-directed antimicrobial therapy. The clinical course was complicated by the requirement of various endovascular prostheses for vascular access. To our knowledge this degree of relapse with guideline medical and surgical therapy is rare and challenges current practice and understanding of this group of infection.

New Gene Responsible for Resistance of Clinical Corynebacteria to Macrolide, Lincosamide and Streptogramin B

The subject of the study was phenotypic marking of the antibiotic susceptibility and MLS_B resistance mechanism in Corynebacterium spp. isolated from human skin (18 isolates) and from clinical materials (19 isolates). The strains were tested for the presence of the erm(A), erm(B), erm(C), erm(X), lnu(A), msr(A), msr(B) and mph(C) genes. Clinical isolates showed wide resistance to antibiotics. In 89% clinical isolates and 72% skin microbiota a constitutive type of MLS_B resistance was found. In 12 clinical isolates the erm(C) gene was detected-eight of which had erm(X) as well as erm(C), two harboured erm(X), erm(C) and erm(A) and two demonstrated only erm(C).

Molecular epidemiology and clinical significance of Corynebacterium striatum isolated from clinical specimens

Purpose

This study investigated the clinical epidemiology, antimicrobial susceptibility, and molecular epidemiology of Corynebacterium striatum isolates.

Patients and methods

An observational study was conducted at a university hospital in the Republic of Korea from August to December 2016. All subjects were patients who tested positive for C. striatum clinically. Clinical data were analyzed to evaluate the microbiological and genotypic characteristics of C. striatum strains.

Results

Sixty-seven C. striatum isolates recovered from non-duplicated patients were characterized. Patients were classified into three groups according to the infection type: nosocomial infection (71.6%), health care-associated infection (8.7%), and community-acquired infection (18.8%). The most common clinical specimens were urine (35.8%) and skin abscesses (32.8%). Fifty-two (77.6%) isolates showed multidrug resistance, defined as resistance to ≥3 different antibiotic families. All strains were susceptible to vancomycin and linezolid. Resistance to other antibiotics varied: penicillin (n=65; 97.0%), ampicillin (n=63; 94.0%), cefotaxime (n=64; 95.5%), and levofloxacin (n=61; 91.0%). Phylogenetic analysis identified all 16 S rRNA gene sequences of the 67 isolates as those of C. striatum, where 98%–99% were homologous to C. striatum ATCC 6940. In multilocus sequence typing for internal transcribed spacer region, gyrA, and rpoB sequencing, the most predominant sequence types (STs) were ST2, ST3, ST6, and ST5.

Conclusion

C. striatum isolates may cause opportunistic infections associated with nosocomial infections through horizontal transmission. The presence of multidrug resistance and intra-hospital dissemination implicate C. striatum isolates as a potential target pathogen for infection control and antimicrobial stewardship programs.

Corynebacterium Species Rarely Cause Orthopedic Infections

Corynebacterium spp. are rarely considered pathogens, but data on Corynebacterium spp. as a cause of orthopedic infections are sparse. Therefore, we asked how often Corynebacterium spp. caused an infection in a defined cohort of orthopedic patients with a positive culture. In addition, we aimed to determine the species variety and the susceptibility of isolated strains to define potential treatment strategies. We retrospectively assessed all bone and joint samples that were collected between 2006 and 2015 from an orthopedic ward and that were positive for Corynebacterium spp. by culture. The isolates were considered relevant to an infection if the same Corynebacterium sp. was present in at least two samples. We found 97 orthopedic cases with isolation of Corynebacterium spp. (128 positive samples). These were mainly Corynebacterium tuberculostearicum (n = 26), Corynebacterium amycolatum (n = 17), Corynebacterium striatum (n = 13), and Corynebacterium afermentans (n = 11). Compared to the species found in a cohort of patients with positive blood cultures hospitalized in nonorthopedic wards, we found significantly more C. striatum- and C. tuberculostearicum-positive cases but no C. jeikeium-positive cases in our orthopedic cohort. Only 16 out of 66 cases (24.2%) with an available diagnostic set of at least two samples had an infection. Antibiotic susceptibility testing (AST) showed various susceptibility results for all antibiotics except vancomycin and linezolid, to which 100% of the isolates were susceptible. The rates of susceptibility of corynebacteria isolated from orthopedic samples and of isolates from blood cultures were comparable. In conclusion, our study results confirmed that a Corynebacterium sp. is most often isolated as a contaminant in a cohort of orthopedic patients. AST is necessary to define the optimal treatment in orthopedic infections.

Successful Treatment of Olecranon Bursitis Caused by Trueperella bernardiae: Importance of Environmental Exposure and Pathogen Identification

A livestock farmer with a history of arthropathy presented with unilateral olecranon bursal swelling and tenderness. Multiple wound and intraoperative cultures revealed growth of Trueperella bernardiae, a Gram-positive coccobacillus, with symptom resolution following appropriate antimicrobial therapy. To our knowledge, this is the first case report of olecranon bursitis caused by this organism. Coryneform bacteria are often regarded as contaminants in clinical cultures, but advanced techniques for species identification may reveal expanded pathogenic potential of individual species like T. bernardiae and elucidate epidemiologic clues for osteoarticular infections in these cases.

Corynebacterium heidelbergense sp. nov., isolated from the preen glands of Egyptian geese (Alopochen aegyptiacus)

Two strains (pedersoli^T and girotti) of a new species of bacteria were isolated from the preen glands of wild Egyptian geese (Alopochen aegyptiacus) from the river Neckar in southern Germany in two subsequent years. The strains were lipophilic, fastidious, Gram-positive rods and belonged to the genus Corynebacterium. Phylogenetically, the isolates were most closely related to Corynebacterium falsenii DSM 44353^T which has been found to be associated with birds before. 16S rRNA gene sequence similarity to all known Corynebacterium spp. was significantly <97%. Corresponding values of rpoB showed low levels of similarity <87% and ANIb was <73%. G+C content of the genomic DNA was 65.0mol% for the type strain of the goose isolates, as opposed to 63.2mol% in Corynebacterium falsenii. MALDI-TOF MS analysis of the whole-cell proteins revealed patterns clearly different from the related species, as did biochemical tests, and polar lipid profiles. We therefore conclude that the avian isolates constitute strains of a new species, for which the name Corynebacterium heidelbergense sp. nov. is proposed. The type strain is pedersoli^T (=DSM 104638^T=LMG 30044^T).

Comparison between disk diffusion and agar dilution methods to determine in vitro susceptibility of Corynebacterium spp. clinical isolates and update of their susceptibility

OBJECTIVES

Although Corynebacterium spp. are part of the microbiota of the skin and mucous membranes, human infections caused by Corynebacterium spp. have been reported and the multidrug resistance pattern of the recovered isolates was emphasised. Due to the usefulness of disk diffusion in daily practice, the purpose of this study was to compare disk diffusion with agar dilution to determine disk diffusion breakpoints and to review the antimicrobial susceptibility of the most frequent Corynebacterium spp. isolated in clinical samples.

METHODS

Susceptibility to 20 antimicrobial agents of 143 Corynebacterium spp. isolates recovered from relevant clinical samples was determined. Comparison between the disk diffusion and agar dilution methods for eight antimicrobial agents was performed to establish new breakpoints using simple linear regression analysis.

RESULTS

All of the isolates tested were susceptible to vancomycin, minocycline and linezolid. A typical susceptibility profile to β-lactam antibiotics among the different species included was not observed. Almost all isolates showed resistance to macrolides and lincosamides. Using a simple linear regression method, it was possible to establish breakpoints for penicillin, erythromycin, clindamycin, gentamicin and ciprofloxacin. However, the low correlation coefficient obtained for vancomycin, minocycline and trimethoprim/sulfamethoxazole did not allow establishment of breakpoints for the disk diffusion method.

CONCLUSION

The disk diffusion method could only be used to evaluate susceptibility to penicillin, erythromycin, clindamycin, gentamicin and ciprofloxacin. These data show that the presence of a Corynebacterium spp. isolate in a clinical sample demands the performance of antimicrobial susceptibility testing since the susceptibility profile is not predictable.

Pharmacokinetic Investigation of Fusidic Acid 1% Viscous Eye Drops in Healthy Volunteers

The biological half-life of fusidic acid was measured in tear fluid samples from the inferior fornix of 14 healthy volunteers after instillation of one drop of viscous fusidic acid eye drops. The study comprised four test days separated by six days of wash-out. On the first test day the concentrations of fusidic acid were measured 1 h after installation, on the second test day 3 h after, on the third test day 6 h after, and on the last day 12 h after instillation. The median fusidic acid concentrations in the tear fluid were 15.7 micrograms/ml, 15.2 micrograms/ml, 10.5 micrograms/ml and 5.6 micrograms/ml on the four days. This corresponds to a biological half-life of 7.3 h. Some of the volunteers reported mild local discomfort lasting a few minutes.

In Vitro Antibiotic Susceptibility Pattern of Non-diphtheriae Corynebacterium Isolates in Ontario, Canada, from 2011 to 2016

Non-diphtheriae Corynebacterium-associated disease has been increasingly observed and often presents a conundrum to the treating physician. Analysis of antibiotic susceptibility testing data for 1,970 clinical Corynebacterium isolates received between 2011 and 2016 revealed that empirical drug treatment options are limited to vancomycin and linezolid. Corynebacterium striatum was the most frequently observed species during this study period, along with C. amycolatum and C. pseudodiphtheriticum/C. propinquum Low levels of susceptibility to penicillin (14.5%), erythromycin (15.1%), and clindamycin (8.7%) were observed for non-diphtheriae Corynebacterium species, while 3.0% of isolates were not susceptible to daptomycin. Similarly, 26.9% and 38.1% of Corynebacterium isolates were susceptible to ciprofloxacin and trimethoprim-sulfamethoxazole, respectively. Our data show much lower susceptibility to penicillin than previously reported in the literature and an increasing number of isolates resistant to daptomycin, highlighting the need for continued antibiotic surveillance studies for appropriate patient management and treatment success.

Multidrug-Resistant Corynebacterium striatum Associated with Increased Use of Parenteral Antimicrobial Drugs

Device-related infections with this pathogen frequently require prolonged parenteral therapy.

Corynebacterium striatum is an emerging multidrug-resistant bacteria. We retrospectively identified 179 isolates in a clinical database. Clinical relevance, in vitro susceptibility, and length of parenteral antimicrobial drug use were obtained from patient records. For patients with hardware- or device-associated infections, those with C. striatum infections were matched with patients infected with coagulase-negative staphylococci for case–control analysis. A total of 87 (71%) of 121 isolates were resistant to all oral antimicrobial drugs tested, including penicillin, tetracycline, clindamycin, erythromycin, and ciprofloxacin. When isolated from hardware or devices, C. striatum was pathogenic in 38 (87%) of 44 cases. Patients with hardware-associated C. striatum infections received parenteral antimicrobial drugs longer than patients with hardware-associated coagulase-negative staphylococci infections (mean ± SD 69 ± 5 days vs. 25 ± 4 days; p<0.001). C. striatum commonly shows resistance to antimicrobial drugs with oral bioavailability and is associated with increased use of parenteral antimicrobial drugs.

Corynebacterium jeikeium endocarditis: A case report and comprehensive review of an underestimated infection

Diphtheroids are gram-positive pleomorphic bacilli in the family of Coryneform bacteria. These organisms are present as part of the human flora. Past practice habits had been to consider them as contaminants when isolated from clinical samples. Corynebacterium jeikeium is one of the most clinically important nondiphtherial Corynebacteria that can cause different forms of infections specifically in patients with underlying risk factors and co-morbidities including immunocompromised subjects. Through this article, we present a 67-year-old gentleman with extensive co-morbidities including heart failure with reduced ejection fraction and ESRD on hemodialysis through a femoral catheter who presented with chest pain and fatigue. Further investigation confirmed diagnosis of C. jeikeium endocarditis. We go on to review previously reported cases of C. jeikeium endocarditis and we will discuss different aspects of C. jeikeium infection with a focus on microbiology, pathophysiology, and treatment.

Occurrence of Corynebacterium striatum as an emerging antibiotic-resistant nosocomial pathogen in a Tunisian hospital

Corynebacterium striatum is a nosocomial opportunistic pathogen increasingly associated with a wide range of human infections and is often resistant to several antibiotics. We investigated the susceptibility of 63 C. striatum isolated at the Farhat-Hached hospital, Sousse (Tunisia), during the period 2011–2014, to a panel of 16 compounds belonging to the main clinically relevant classes of antimicrobial agents. All strains were susceptible to vancomycin, linezolid, and daptomycin. Amikacin and gentamicin also showed good activity (MICs₉₀ = 1 and 2 mg/L, respectively). High rates of resistance to penicillin (82.5%), clindamycin (79.4%), cefotaxime (60.3%), erythromycin (47.6%), ciprofloxacin (36.5%), moxifloxacin (34.9%), and rifampicin (25.4%) were observed. Fifty-nine (93.7%) out of the 63 isolates showed resistance to at least one compound and 31 (49.2%) were multidrug-resistant. Twenty-nine resistance profiles were distinguished among the 59 resistant C. striatum. Most of the strains resistant to fluoroquinolones showed a double mutation leading to an amino acid change in positions 87 and 91 in the quinolone resistance-determining region of the gyrA gene. The 52 strains resistant to penicillin were positive for the gene bla, encoding a class A β-lactamase. Twenty-two PFGE patterns were identified among the 63 C. striatum, indicating that some clones have spread within the hospital.

Milk Hygiene in Rural Southwestern Uganda: Prevalence of Mastitis and Antimicrobial Resistance Profiles of Bacterial Contaminants of Milk and Milk Products

Mastitis and antimicrobial resistance are a big challenge to the dairy industry in sub-Saharan Africa. A study was conducted in Kashongi and Keshunga subcounties of Kiruhura District (in Uganda) where the government and private sector have deliberate programs to improve production efficiency, quality, and safety of milk and its products. The study aimed to determine the prevalence of mastitis, its common causative agents, antimicrobial sensitivity of mastitis causing organisms, and contaminants of processed milk products: yoghurt and ghee. Seventy-one milk, fourteen yoghurt, and three ghee samples were collected from nine farms. Of the 71 cows tested, 54 (76.1%) had mastitis. The mastitis cases from Keshunga were 32 (59.3%) and Kashongi contributed 22 (40.7%) of the cases. The common mastitis causative agents were Staphylococcus spp. (30.8%), Streptococcus spp. (12.3%), Corynebacterium spp.(15.4%), and E. coli (7.7%). Some of the isolates were resistant to tetracycline and penicillin. Prevalent contaminants of yoghurt were Staphylococcus spp. (8.3%), Streptococcus spp. (8.3%), Corynebacterium spp. (8.3%), and E. coli (8.3%), whereas all ghee contained Streptococcus spp. (100%). Prevalence of mastitis, antimicrobial resistance, and contamination of milk products are high in the study area. Targeted programs to prevent and control mastitis as well as antibiotic resistance are recommended.

Resilient microorganisms in dust samples of the International Space Station-survival of the adaptation specialists

BACKGROUND

The International Space Station (ISS) represents a unique biotope for the human crew but also for introduced microorganisms. Microbes experience selective pressures such as microgravity, desiccation, poor nutrient-availability due to cleaning, and an increased radiation level. We hypothesized that the microbial community inside the ISS is modified by adapting to these stresses. For this reason, we analyzed 8-12 years old dust samples from Russian ISS modules with major focus on the long-time surviving portion of the microbial community. We consequently assessed the cultivable microbiota of these samples in order to analyze their extremotolerant potential against desiccation, heat-shock, and clinically relevant antibiotics. In addition, we studied the bacterial and archaeal communities from the stored Russian dust samples via molecular methods (next-generation sequencing, NGS) and compared our new data with previously derived information from the US American ISS dust microbiome.

RESULTS

We cultivated and identified in total 85 bacterial, non-pathogenic isolates (17 different species) and 1 fungal isolate from the 8-12 year old dust samples collected in the Russian segment of the ISS. Most of these isolates exhibited robust resistance against heat-shock and clinically relevant antibiotics. Microbial 16S rRNA gene and archaeal 16S rRNA gene targeting Next Generation Sequencing showed signatures of human-associated microorganisms (Corynebacterium, Staphylococcus, Coprococcus etc.), but also specifically adapted extremotolerant microorganisms. Besides bacteria, the detection of archaeal signatures in higher abundance was striking.

CONCLUSIONS

Our findings reveal (i) the occurrence of living, hardy microorganisms in archived Russian ISS dust samples, (ii) a profound resistance capacity of ISS microorganisms against environmental stresses, and (iii) the presence of archaeal signatures on board. In addition, we found indications that the microbial community in the Russian segment dust samples was different to recently reported US American ISS microbiota.

Retrospective Evaluation of Canine Dermatitis Secondary to Corynebacterium spp

Corynebacterium species are considered nonpathogenic in canine dermatitis; however, potential clinical significance has been demonstrated in canine otitis externa and from a dog bite wound in a human. Objectives of this study were to identify the predominant Corynebacterium species present in lesions of canine dermatitis, assess pathogenic role, determine antimicrobial susceptibility, and evaluate clinical response. Of 37 isolates identified as Corynebacterium, 31 were Corynebacterium auriscanis . Most Corynebacterium isolates were susceptible to chloramphenicol (97%), tetracyclines (92%), and amikacin (89%); isolate susceptibilities to β-lactams, trimethoprim-sulfonamides, and fluoroquinolones were <50%. Most cultures grew mixed populations of bacteria; C. auriscanis was the only organism isolated in three patients. At recheck, 2-8 wk after initial presentation, pleomorphic rods were absent or significantly decreased in all patients. Two of three C. auriscanis isolates were obtained in pure culture and were evaluable, meaning patient had an initial exam and recheck examination. Both patients were already on antimicrobials to which C. auriscanis was resistant in vitro. Both improved after doxycycline administration. C. auriscanis may act as an opportunistic pathogen in canine dermatitis and may not respond to antimicrobial therapy based on susceptibilities for other organisms in mixed infections. Occasionally, Corynebacterium isolated alone may be pathogenic.

Cystic Neutrophilic Granulomatous Mastitis: Association With Gram-Positive Bacilli and Corynebacterium

OBJECTIVES

To determine whether cystic neutrophilic granulomatous mastitis (CNGM) can be associated with Gram-positive bacilli and Corynebacterium

METHODS

We reviewed our experience with 35 granulomatous mastitis patients over a 10-year period, including histologic pattern, Gram stain and other microbiologic data, clinical presentation, treatment and outcome.

RESULTS

Biopsies from 19 patients demonstrated CNGM, while 16 patients had other patterns of granulomatous mastitis. Gram-positive organisms were seen within microcystic spaces in 16/19 CNGM, but 0/16 non-CNGM patients (P = .000). Culture or molecular studies demonstrated Corynebacterium species in three, all CNGM. Patients with CNGM were more likely to be younger, of Hispanic ethnicity, and born outside of the United States. Granulomatous mastitis resolved after a protracted course with widely variable treatment (antibiotics, surgery, steroids).

CONCLUSIONS

Our data further support CNGM as an infectious disease; further study of Corynebacterium-directed therapy in CNGM is needed.

Corynebacterium uropygiale sp. nov., isolated from the preen gland of Turkeys (Meleagris gallopavo)

A novel species of fastidious, lipophilic, club-shaped, Gram-positive bacteria was recovered from the preen glands of healthy Turkeys (Meleagris gallopavo) from two different locations. Phylogenetic analysis of the 16S rRNA gene showed highest similarity to Corynebacterium spheniscorum DSM 44757(T) (96.8%) with a 3.2kb stretch of rpoB sharing 82.4% sequence similarity to the same species. DNA fingerprinting by ERIC-PCR and polar lipid profiles clearly differentiated the Turkey isolates from the most closely related Corynebacteria, as did MALDI-TOF MS analysis. Chemotaxonomic tests revealed the presence of corynemycolic acids with C16:0, C18:0, C18:1ω9c and tuberculostearic acid as the major cellular fatty acids. The G+C content of the type strain was 60.7 mol%. The species was susceptible to ampicillin, kanamycin A, streptomycin, amikacin, polymyxin B and vancomycin. From our results, it becomes evident that the isolated organisms represent a new species, for which the name Corynebacterium uropygiale sp. nov. is proposed. The type strain is Iso10(T) (=DSM 46817(T)=LMG 28616(T)).

Non Diphtheritic Corynebacteria: An Emerging Nosocomial Pathogen in Skin and Soft Tissue Infection

INTRODUCTION

Non-diphtheritic corynebacteria are normal inhabitants of skin and mucous membrane. When isolated from clinical specimens they are often considered as contaminants. Recent reports suggest their role as emerging nosocomial pathogens.

AIM

To speciate non-diphtheritic corynebacteria isolated from wound specimens, to correlate their clinical significance and to determine their invitro antimicrobial susceptibilities to 9 antimicrobial agents.

MATERIALS AND METHODS

Twenty five non-diphtheritic corynebacteria from skin and soft tissue infections were selected for study. Isolates were identified by battery of tests and minimum inhibitory concentration (MIC) was detected by Clinical & Laboratory Standards Institute (CLSI) described broth microdilution method. MIC was interpreted according CLSI and British Society for Antimicrobial Chemotherapy (BSAC) guidelines.

RESULTS

C. amycolatum was the predominant species (20%) followed by C. striatum (16%). Penicillin was least effective invitro followed by clindamycin and ciprofloxacin. Excellent activities were shown by vancomycin, linezolid and imipenem. Multidrug resistance was found in all the species.

CONCLUSION

Non-diphtheritic corynebacteria are potential nosocomial pathogens among acute/chronic complicated skin and soft tissue infection. Vancomycin or linezolid can be used empirically to treat such infections until the invitro susceptibility results are available.

A thiol-disulfide oxidoreductase of the Gram-positive pathogen Corynebacterium diphtheriae is essential for viability, pilus assembly, toxin production and virulence

The Gram-positive pathogen Corynebacterium diphtheriae exports through the Sec apparatus many extracellular proteins that include the key virulence factors diphtheria toxin and the adhesive pili. How these proteins attain their native conformations after translocation as unfolded precursors remains elusive. The fact that the majority of these exported proteins contain multiple cysteine residues and that several membrane-bound oxidoreductases are encoded in the corynebacterial genome suggests the existence of an oxidative protein-folding pathway in this organism. Here we show that the shaft pilin SpaA harbors a disulfide bond in vivo and alanine substitution of these cysteines abrogates SpaA polymerization and leads to the secretion of degraded SpaA peptides. We then identified a thiol-disulfide oxidoreductase (MdbA), whose structure exhibits a conserved thioredoxin-like domain with a CPHC active site. Remarkably, deletion of mdbA results in a severe temperature-sensitive cell division phenotype. This mutant also fails to assemble pilus structures and is greatly defective in toxin production. Consistent with these defects, the ΔmdbA mutant is attenuated in a guinea pig model of diphtheritic toxemia. Given its diverse cellular functions in cell division, pilus assembly and toxin production, we propose that MdbA is a component of the general oxidative folding machine in C. diphtheriae.

Antimicrobial Treatment Options for Granulomatous Mastitis Caused by Corynebacterium Species

Corynebacterium species are increasingly recognized as important pathogens in granulomatous mastitis. Currently, there are no published treatment protocols for Corynebacterium breast infections. This study describes antimicrobial treatment options in the context of other management strategies used for granulomatous mastitis. Corynebacterium spp. isolated from breast tissue and aspirate samples stored from 2002 to 2013 were identified and determined to the species level using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), 16S RNA sequencing, and rpoB gene targets. The MICs for 12 antimicrobials were performed using Etest for each isolate. Correlations of these with antimicrobial characteristics, choice of antimicrobial, and disease outcome were evaluated. Corynebacterium spp. from breast tissue and aspirate samples were confirmed in 17 isolates from 16 patients. Based on EUCAST breakpoints, Corynebacterium kroppenstedtii isolates (n = 11) were susceptible to seven antibiotic classes but resistant to β-lactam antibiotics. Corynebacterium tuberculostearicum isolates (n = 4) were multidrug resistant. Two nonlipophilic species were isolated, Corynebacterium glucuronolyticum and Corynebacterium freneyi, both of which have various susceptibilities to antimicrobial agents. Short-course antimicrobial therapy was common (median, 6 courses per subject; range, 1 to 9 courses). Patients with C. kroppenstedtii presented with a hot painful breast mass and underwent multiple surgical procedures (median, 4 procedures; range, 2 to 6 procedures). The management of Corynebacterium breast infections requires a multidisciplinary approach and includes culture and appropriate sensitivity testing to guide antimicrobial therapy. Established infections have a poor outcome, possibly because adequate concentrations of some drugs will be difficult to achieve in lipophilic granulomata. Lipophilic antimicrobial therapy may offer a therapeutic advantage. The role of immunotherapy has not been defined.

Seminal Corynebacterium strains in infertile men with and without leucocytospermia

This study aimed to identify seminal Corynebacterium strains in infertile men with and without leucocytospermia. Semen samples from 60 infertile men were allocated into two equal groups: semen samples with leucocytospermia and semen samples without leucocytospermia. Semen culture for Corynebacterium species was carried out on Columbia agar medium confirmed by Gram-stained film and biochemical tests followed by analytical profile index biotyping and antibiotic susceptibility. Bacterial isolates were detected in 20/60 semen cultures (33.3%) as Corynebacteria, Staphylococci, Alpha haemolytic streptococci and E. coli. In all, 12/60 (20%) had Corynebacterium positive semen culture, whereas C. seminal was the major isolated species followed by C. amycolatum, C. jekium and C. urealyticum. There was nonsignificant difference between patients with/without Corynebacterium positive culture regarding sperm concentration and normal sperm morphology; however, in positive cultures sperm motility was significantly lower compared with negative cultures. Antimicrobial sensitivity among Corynebacteria strains was highest for vancomycin, rifampicin then imipenem, ampicillin + sulbactam, ciprofloxacin. It is concluded that positive semen cultures for different Corynebacteria species were demonstrated in infertile men, whereas Corynebacterium seminale was the most common isolated species. Vancomycin, rifampicin then imipenem and ampicillin + sulbactam are recommended as sensitive antibiotics.

Successful treatment of Corynebacterium urealyticum encrusting cystitis with systemic and intravesical antimicrobial therapy

A 6-year-old Saint Bernard dog was diagnosed with encrusting cystitis caused by Corynebacterium urealyticum. The infection persisted despite the prolonged use of antimicrobials and surgical debridement of the urinary bladder. Resolution occurred following intravenous vancomycin, urine acidification, and intravesical gentamicin. The challenges involved in the treatment of encrusting cystitis are described.

Complete Genome Sequence of Corynebacterium minutissimum, an Opportunistic Pathogen and the Causative Agent of Erythrasma

Corynebacterium minutissimum was first isolated in 1961 from infection sites of patients presenting with erythrasma, a common cutaneous infection characterized by a rash. Since its discovery, C. minutissimum has been identified as an opportunistic pathogen in immunosuppressed cancer and HIV patients. Here, we report the whole-genome sequence of C. minutissimum.

Postoperative Abdominal Infection Caused by Corynebacterium minutissimum

Corynebacterium minutissimum is a non-spore forming, gram-positive, aerobic or facultative anaerobic bacillus. It is the causative organism of erythrasma, a common superficial infection of skin, which typically presents as reddish-brown macular patches. To date, it has rarely been found to cause invasive disease, although other non-diphtheria corynebacteria are becoming increasingly common as opportunistic pathogens. We report on a rare case of abdominal infection due to C. minutissimum in an immunocompetent adult who was successfully treated with intravenous amoxicillin/sulbactam.

Surgical lead extraction for total occlusion of the superior vena cava by chronic lead infection after mustard procedure

We present a case of total occlusion of the superior vena cava (SVC) with extensive thrombosis of the adjacent large veins secondary to multiple abandoned pacemaker leads with a superimposed chronic lead infection by Corynebacterium jeikeium. A surgical lead extraction was performed with an extensive en-bloc resection of the SVC together with the right subclavian vein and the right innomate vein. No venous reconstruction was required because of an unobstructed runoff via a well-developed azygos system.

Non-diphtheriae Corynebacterium species: an emerging respiratory pathogen

The purpose of the study was to describe the microbiological and clinical features of ten cases of lower respiratory tract infection due to Corynebacterium striatum, Corynebacterium propinquum and Corynebacterium pseudodiphtheriticum. Respiratory samples were recovered from hospitalised patients who were diagnosed of pneumonia and exacerbations of chronic respiratory infections. The samples were Gram-stained and seeded on conventional bacterial growing media. Bacteria were identified by matrix-assisted linear desorption/ionisation-time-of-flight mass spectrometry (MALDI-TOF MS). Antibiotic susceptibility was tested by the disk diffusion method. All patients presented an acute respiratory onset, most of them in the context of an underlying disease and/or immunosuppression. In all patients, the microscopical examination of Gram-stained respiratory samples showed numerous polymorphonuclear cells and Gram-positive bacilli, suggestive of the Corynebacterium morphotype. A pure culture growth of Corynebacterium was obtained in the majority (72 %) of samples. The conclusions are that non-diphtheriae Corynebacterium species are an emerging cause of respiratory infection among patients with chronic respiratory disease and/or immunosuppression, and cannot always be considered as mere colonisers. The microorganism's predominance in Gram-stained purulent respiratory samples together with abundant growth in the culture is the key for the microbiological diagnosis.