Drug sensitivity and clinical impact of members of the genus Kocuria

Troubleshooting high laboratory pasteurization counts in organic raw milk requires characterization of dominant thermoduric bacteria, which includes nonsporeformers as well as sporeformers

Laboratory pasteurization count (LPC) enumerates thermoduric bacteria and is one parameter used to assess raw milk quality. No regulatory limit has presently been set for LPC, but LPC data are used by some dairy processors and cooperatives to designate raw milk quality premiums paid to farmers and may also be used for troubleshooting bacterial contamination issues. Although it is occasionally used as a proxy for levels of bacterial spores in raw milk, limited knowledge is available on the types of organisms that are enumerated by LPC in contemporary raw milk supplies. Although historical studies have reported that thermoduric bacteria quantified by LPC may predominantly represent gram-positive cocci, updated knowledge on microbial populations enumerated by LPC in contemporary organic raw milk supplies is needed. To address this gap, organic raw milk samples from across the United States (n = 94) were assessed using LPC, and bacterial isolates were characterized. LPC ranged from below detection (<0.70 log cfu/mL) to 4.07 log cfu/mL, with a geometric mean of 1.48 log cfu/mL. Among 380 isolates characterized by 16S rDNA sequencing, 52.6%, 44.5%, and 2.4% were identified as gram-positive sporeformers, gram-positive nonsporeformers, and gram-negatives, respectively; 0.5% could not be categorized into those groups because they could only be assigned a higher level of taxonomy. Isolates identified as gram-positive sporeformers were predominantly Bacillus (168/200), and gram-positive nonsporeformers were predominantly Brachybacterium (56/169) and Kocuria (47/169). To elucidate if the LPC level can be an indicator of the type of thermoduric (e.g., sporeforming bacteria) present in raw milk, we evaluated the proportion of sporeformers in raw milk samples with LPC of ≤100 cfu/mL, 100 to 200 cfu/mL, and ≥200 cfu/mL (51%, 67%, and 35%), showing a trend for sporeformers to represent a smaller proportion of the total thermoduric population when LPC increases, although overall linear regression showed no significant association between the proportion of sporeformers and the LPC concentration. Hence, LPC level alone provides no insight into the makeup of the thermoduric population in raw milk, and further characterization is needed to elucidate the bacterial drivers of elevated LPC in raw milk. We therefore further characterized the isolates from this study using MALDI-TOF mass spectrometry (MALDI-TOF MS), a rapid microbial identification tool that is more readily available to dairy producers than 16S rDNA PCR and sequencing. Although our data indicated agreement between 16S rDNA sequencing and MALDI-TOF MS for 66.6% of isolates at the genus level, 24.2% and 9.2% could not be reliably identified or were mischaracterized using MALDI-TOF MS, respectively. This suggests that further optimization of this method is needed to allow for accurate characterization of thermoduric organisms commonly found in raw milk. Ultimately, our study provides a contemporary perspective on thermoduric bacteria selected by the LPC method and establishes that the LPC alone is not sufficient for identifying the bacterial drivers of LPC levels. Further development of rapid characterization methods that are accessible to producers, cooperatives, and processors will support milk quality troubleshooting efforts and ultimately improve outcomes for dairy industry community members.

Kocuria kristinae-Induced Infective Endocarditis: Unveiling an Emerging Threat in Clinical Practice

Infective endocarditis (IE) remains a formidable challenge in clinical practice due to several causative agents, each presenting with unique diagnostic and therapeutic dilemmas. Kocuria kristinae, a coagulase-negative, catalase-positive Gram-positive coccus, has recently emerged as an uncommon but increasingly recognized pathogen in the cause of IE. This case report highlights the clinical characteristics, risk factors, and challenges associated with Kocuria kristinae-induced IE. We conducted a comprehensive literature review and identified several case reports on Kocuria kristinae as a causative agent. Due to its indolent nature and the subtle presentation of symptoms, along with its ability to form biofilms, delayed diagnosis of Kocuria is often seen, thereby emphasizing the need for heightened clinical suspicion. The predisposing factors for Kocuria kristinae infection include underlying cardiac abnormalities, prosthetic heart valves, and immunocompromised states. Additionally, antimicrobial susceptibility patterns and optimal treatment strategies remain unclear, warranting further investigation. This abstract presents the case of a 75-year-old male with IE secondary to Kocuria kristinae on a prosthetic mitral valve. We aim to highlight the need for increased awareness among clinicians to facilitate early recognition and prompt initiation of targeted therapeutic interventions. Unraveling the intricacies of Kocuria kristinae's pathogenicity is crucial for refining diagnostic approaches and optimizing patient outcomes.

Kocuria species: an underappreciated pathogen in pediatric patients-a single-center retrospective analysis of 10 years' experience in China

Kocuria species are known to be opportunistic pathogens that cause infections in humans, especially immunocompromised hosts. However, reports of pediatric patients are limited. This retrospective study was designed to investigate the spectrum of infections in pediatric patients caused by Kocuria species. Thirty-six patients were enrolled; of these, 29 were infected by Kocuria kristinae, 4 by Kocuria roseus, 2 by Kocuria varians, and 1 by Kocruria rhizophila. Twenty-six patients were diagnosed with bloodstream infection; 6 had ventilator-associated pneumonia; and one each had a catheter-associated urinary tract infection, purulent meningitis, cholangitis, and empyema. Twenty-seven patients were immunocompromised or debilitating, had congenital abnormalities or fitted with indwelling devices. Nine patients were immunocompetent, 4 with early onset before 1 year of age. All Kocuria species were susceptible to lenezolid, vancomycin, and tigecycline; while showing frequent resistance to penicillin and oxacillin. Most cases were cured by administering appropriate antimicrobial agents. To our knowledge, this is the largest case series of pediatric patients with Kocuria species infection. We highlight Kocuria species should be considered as an underappreciated pathogen in pediatric patients.

Kocuria kristinae neuroinfection in an immunocompetent patient: a case report and review of the literature

Few cases of disease by Kocuria kristinae have been reported, some in immunocompetent patients but mainly in immunocompromised. The current case report describes a 28-year-old female with an initial diagnosis of pituitary macroadenoma. After the initial surgery, the patient was readmitted due to tension pneumocephalus and cerebrospinal fluid (CSF) fistula. Cultures showed K. kristinae in the CSF and Candida albicans in the urine. The patient died after multiple complications. This is the first case of neuroinfection by K. kristinae in the American continent as reviewed. It was not determined as the main cause of death due to the sudden herniation, however, with active infection derived from the identification in two different samples, for this reason, we consider that it could be useful to take it as a cause of disease and a probable cause when the studies for detection of the most common pathogens have been negative.

First Report of Kocuria kristinae in the Skin of a Cuban Boa (Epicrates angulifer)

During a routine clinical examination of a four-year-old female Cuban boa (Epicrates angulifer) belonging to a zoological park located in northern Portugal, a skin lesion was observed. A skin swab was taken. Bacteriological analysis conducted using the Vitek® 2 Compact system identified the presence of the bacteria species Kocuria kristinae, a new bacterial pathogen that may be a potential pathogen in wild animals. This K. kristinae strain was resistant to kanamycin, pradofloxacin, erythromycin, clindamycin, tetracycline, nitrofurantoin, and trimethoprim/sulphamethoxazole and was therefore classified as a multidrug-resistant bacterium. To the authors' knowledge, this is the first time that K. kristinae has been described in the skin of a Cuban boa. This report serves as a cautionary warning about the importance of recognising and investigating the potential pathogenicity of this agent, as well as contributing to the development of strategies to prevent the spread of antibiotic-resistant microorganisms.

Kocuria Species Infections in Humans-A Narrative Review

Kocuria species are catalase-positive and coagulase-negative Gram-positive coccoid bacteria that belong to the family Micrococcaceae, order Actinomycetales, and class Actinobacteria. Even though they may be relatively rare, they have been increasingly reported as the causes of human infections lately. The present study aims to review all published cases of Kocuria spp. infections in humans reporting data on epidemiology, microbiology, antimicrobial susceptibility, antimicrobial treatment, and mortality. A narrative review was performed based on a search of Pubmed and Scopus databases in the literature. In total, 73 studies provided data on 102 patients with Kocuria spp. infections. The mean age of patients was 47 years, and 68.3% were male. The most common types of infection were bacteremia (36.3%), skin and soft tissue infection (18.6%), endophthalmitis (15.7%), infective endocarditis (13.7%), and peritonitis (11.8%), most commonly peritoneal-dialysis-associated. The most frequently isolated species was K. kristinae (46.1%), and antimicrobial resistance was lower for vancomycin (7%) and tetracyclines (6.7%). Vancomycin (47%), cephalosporins (39.6%), and quinolones (36.6%) were the most commonly used antimicrobials. The empirical antimicrobial treatment of Kocuria spp. infections should include vancomycin as long as antimicrobial susceptibility results are pending. The infection outcome mainly depends on the type of infection and is higher for infective endocarditis. Endophthalmitis is associated with increased rates of low visual acuity after treatment.

Kocuria rhizophila prosthetic hip joint infection

We present the first case report of prosthetic joint infection (PJI) caused by Kocuria rhizophila. Our patient is a 74-year-old male who underwent primary total hip replacement for right hip pain. His recovery was uneventful until 6 weeks postoperatively when he presented to his routine outpatient appointment with significant erythema, swelling, and tenderness over his right hip wound. Based on the acuity of his symptoms and the radiological findings, it was determined that the patient should undergo debridement, antibiotics, and implant retention (DAIR procedure). A consensus decision was also made at our PJI multidisciplinary meeting to treat him with 12 weeks of IV antibiotics. After completing this 12 weeks course of IV Vancomycin, his inflammatory markers returned to normal limits. At 6 months follow-up, our patient was mobilizing independently without any signs of infection recurrence. His radiographs showed the implant was in a satisfactory position with no evidence of loosening. This case adds to an emerging body of literature describing invasive infections associated with Kocuria species. We have demonstrated the effectiveness of managing this condition with debridement, implant retention, and IV Vancomycin therapy for 12 weeks.

Stalactites Core Prospect as Environmental "Microbial Ark": The Actinomycetota Diversity Paradigm, First Reported from a Greek Cave

Speleothems found in caves worldwide are considered the natural libraries of paleontology. Bacteria found in these ecosystems are generally limited to Proteobacteria and Actinomycetota, but rare microbiome and "Dark Matter" is generally under-investigated and often neglected. This research article discusses, for the first time to our knowledge, the diachronic diversity of Actinomycetota entrapped inside a cave stalactite. The planet's environmental microbial community profile of different eras can be stored in these refugia (speleothems). These speleothems could be an environmental "Microbial Ark" storing rare microbiome and "Dark Matter" bacterial communities evermore.

A new pathogenic isolate of Kocuria kristinae identified for the first time in the marine fish Larimichthys crocea

In recent years, new emerging pathogenic microorganisms have frequently appeared in animals, including marine fish, possibly due to climate change, anthropogenic activities, and even cross-species transmission of pathogenic microorganisms among animals or between animals and humans, which poses a serious issue for preventive medicine. In this study, a bacterium was clearly characterized among 64 isolates from the gills of diseased large yellow croaker Larimichthys crocea that were raised in marine aquaculture. This strain was identified as K. kristinae by biochemical tests with a VITEK 2.0 analysis system and 16S rRNA sequencing and named K. kristinae_LC. The potential genes that might encode virulence-factors were widely screened through sequence analysis of the whole genome of K. kristinae_LC. Many genes involved in the two-component system and drug-resistance were also annotated. In addition, 104 unique genes in K. kristinae_LC were identified by pan genome analysis with the genomes of this strain from five different origins (woodpecker, medical resource, environment, and marine sponge reef) and the analysis results demonstrated that their predicted functions might be associated with adaptation to living conditions such as higher salinity, complex marine biomes, and low temperature. A significant difference in genomic organization was found among the K. kristinae strains that might be related to their hosts living in different environments. The animal regression test for this new bacterial isolate was carried out using L. crocea, and the results showed that this bacterium could cause the death of L. crocea and that the fish mortality was dose-dependent within 5 days post infection, indicating the pathogenicity of K. kristinae_LC to marine fish. Since K. kristinae has been reported as a pathogen for humans and bovines, in our study, we revealed a new isolate of K. kristinae_LC from marine fish for the first time, suggesting the potentiality of cross-species transmission among animals or from marine animals to humans, from which we would gain insight to help in future public prevention strategies for new emerging pathogens.

The Combined Effect of Potential Probiotic Bacillus licheniformis MCC 2514 and Bifidobacterium breve NCIM 5671 Towards Anti-inflammatory Activity on HT-29 Cell Lines

Probiotics are considered a natural source for treating many intestinal disorders, which deliver health benefits in different ways. The study aims to evaluate the immunomodulatory gene expression on HT-29 cell line using Bacillus licheniformis MCC 2514 and Bifidobacterium breve NCIM 5671 as a single culture and in combination. Upon inflammation induced by LPS, the combination of bacteria downregulated the pro-inflammatory cytokines IL-1α (13.4), IL-12 (14.6), IL-8 (2.6), and IL-6 (1.9), and in contrast, TNF-α (21.2) folds has upregulated. However, anti-inflammatory genes such as IL-4 (0.6), IL-10 (2.9), TGF-2 (92.2), and TGF-3 (85.8) folds were upregulated. The combination of bacteria against oxidative stress downregulated the pro-inflammatory cytokines such as IL-1α & β, IL-6, IL-8, IL-12, and IL-18, and upregulated the anti-inflammatory cytokines IL-10, IL-4, TGF-2, and TGF-3. On the introduction of Kocuria rhizophila, the pro-inflammatory cytokines were upregulated. On supplementation of B. licheniformis and B. breve, the upregulated pro-inflammatory cytokines were decreased, and anti-inflammatory cytokines such as IL-4 (6.2), IL-10 (23.5), TGF-2 (166), and TGF-3(28.4) folds were increased. However, gene expression of toll-like receptor-2 was found high (26 folds) upon introducing probiotic bacteria. ELISA results of Interferon-γ found that the expression was higher (7.19 ng/mL) on the introduction of both the bacteria in combination. The higher anti-inflammatory activity was observed when potential probiotic bacteria were used in combination compared to a single culture. Overall study indicates that the combination of aerobic B. licheniformis and anaerobic B. breve has an anti-inflammatory activity that can sustain an excellent gastrointestinal environment during pathogen invasion and inflammation.

Kocuria rosea Bacteremia in a Sickle Cell Patient: A Case Report

Central line-associated bloodstream infections (CLABSI) are a significant risk factor for poor patient outcomes. It is important to correctly diagnose and treat these infections to ensure the best chance of recovery. Kocuria rosea is a novel bacteria that is native to the human flora and has been on the rise as a culprit in recent nosocomial infections. However, due to its characteristics, it is often misclassified by commonly used hospital tests. We present a case of a 55-year-old female with sickle cell disease who developed a K. rosea infection during her hospital course and was effectively diagnosed and treated. This case report aims to bring awareness to this unusual bacteria as a possible cause of inpatient infection and CLABSI. Further research should be conducted to determine the incidence of this bacteria and the best testing to be done for its proper recognition.

Conjunctival Intraepithelial Lymphocytes, Lacrimal Cytokines and Ocular Commensal Microbiota: Analysis of the Three Main Players in Allergic Conjunctivitis

Conjunctival intraepithelial lymphocytes, tear soluble molecules and commensal microbiota have important roles in the ocular mucosal immune response in healthy and diseased subjects. For the purpose of this study, the cellular and microbial populations of the conjunctiva and the lacrimal soluble molecules were analyzed to find the main biomarkers in allergic conjunctivitis. A total of 35 healthy subjects, 28 subjects with seasonal allergic conjunctivitis and 32 subjects with perennial allergic conjunctivitis were recruited to obtain peripheral blood, conjunctival brush cytology, tear fluid and microbiota samples. Flow cytometry for lymphocytes, multiplex bead assays for cytokines and high-throughput DNA sequencing for microbiome analysis were used. For perennial allergic conjunctivitis, an increased proportion of Th2 and NKT lymphocytes was found, while CD3+TCRγδ+ lymphocytes and double negative MAIT cells were decreased. In contrast, seasonal allergic conjunctivitis was distinguished by an increase in Th17 and Th22 cell proportions, while the Th1 cell proportion decreased. Among tear fluid, the vast majority of pro-inflammatory cytokines (especially Th2 and Th17 cytokines) in perennial allergies and MMP-9 together with IgA in seasonal allergies were increased. In contrast, TGF-β2 was decreased in both forms of conjunctivitis. Finally, fungal (Malassezia species) and bacterial (Kocuria and Propionobacterium acnes species) colonization were observed in the perennial allergic conjunctivitis group. These results provide the basis for the development of a disease profile for perennial allergic conjunctivitis and open the door to new therapeutic and diagnostic strategies.

Annotating unknown species of urban microorganisms on a global scale unveils novel functional diversity and local environment association

In urban ecosystems, microbes play a key role in maintaining major ecological functions that directly support human health and city life. However, the knowledge about the species composition and functions involved in urban environments is still limited, which is largely due to the lack of reference genomes in metagenomic studies comprises more than half of unclassified reads. Here we uncovered 732 novel bacterial species from 4728 samples collected from various common surface with the matching materials in the mass transit system across 60 cities by the MetaSUB Consortium. The number of novel species is significantly and positively correlated with the city population, and more novel species can be identified in the skin-associated samples. The in-depth analysis of the new gene catalog showed that the functional terms have a significant geographical distinguishability. Moreover, we revealed that more biosynthetic gene clusters (BGCs) can be found in novel species. The co-occurrence relationship between BGCs and genera and the geographical specificity of BGCs can also provide us more information for the synthesis pathways of natural products. Expanded the known urban microbiome diversity and suggested additional mechanisms for taxonomic and functional characterization of the urban microbiome. Considering the great impact of urban microbiomes on human life, our study can also facilitate the microbial interaction analysis between human and urban environment.

Exposure to Trypanosoma parasites induces changes in the microbiome of the Chagas disease vector Rhodnius prolixus

BACKGROUND

The causative agent of Chagas disease, Trypanosoma cruzi, and its nonpathogenic relative, Trypanosoma rangeli, are transmitted by haematophagous triatomines and undergo a crucial ontogenetic phase in the insect's intestine. In the process, the parasites interfere with the host immune system as well as the microbiome present in the digestive tract potentially establishing an environment advantageous for development. However, the coherent interactions between host, pathogen and microbiota have not yet been elucidated in detail. We applied a metagenome shotgun sequencing approach to study the alterations in the microbiota of Rhodnius prolixus, a major vector of Chagas disease, after exposure to T. cruzi and T. rangeli focusing also on the functional capacities present in the intestinal microbiome of the insect.

RESULTS

The intestinal microbiota of R. prolixus was dominated by the bacterial orders Enterobacterales, Corynebacteriales, Lactobacillales, Clostridiales and Chlamydiales, whereas the latter conceivably originated from the blood used for pathogen exposure. The anterior and posterior midgut samples of the exposed insects showed a reduced overall number of organisms compared to the control group. However, we also found enriched bacterial groups after exposure to T. cruzi as well as T rangeli. While the relative abundance of Enterobacterales and Corynebacteriales decreased considerably, the Lactobacillales, mainly composed of the genus Enterococcus, developed as the most abundant taxonomic group. This applies in particular to vectors challenged with T. rangeli and at early timepoints after exposure to vectors challenged with T. cruzi. Furthermore, we were able to reconstruct four metagenome-assembled genomes from the intestinal samples and elucidate their unique metabolic functionalities within the triatomine microbiome, including the genome of a recently described insect symbiont, Candidatus Symbiopectobacterium, and the secondary metabolites producing bacteria Kocuria spp.

CONCLUSIONS

Our results facilitate a deeper understanding of the processes that take place in the intestinal tract of triatomine vectors during colonisation by trypanosomal parasites and highlight the influential aspects of pathogen-microbiota interactions. In particular, the mostly unexplored metabolic capacities of the insect vector's microbiome are clearer, underlining its role in the transmission of Chagas disease. Video Abstract.

Isolation and characterization of halophilic Kocuria salsicia strains from cheese brine

Kocuria salsicia can survive in extreme environments and cause infections, including catheter-related bacteremia, in humans. Here, we investigated and evaluated the characteristics of nine K. salsicia strains (KS1–KS9) isolated from cheese brine from a farmstead cheese-manufacturing plant in Korea from June to December, 2020. Staphylococcus aureus American Type Culture Collection (ATCC) 29213 was used as a positive control in the growth curve analysis and biofilm-formation assays. All K. salsicia isolates showed growth at 15% salt concentration and temperatures of 15°C, 25°C, 30°C, 37°C, and 42°C. KS6 and KS8 showed growth at 5°C, suggesting that they are potential psychrotrophs. In the biofilm-formation analysis via crystal violet staining, KS6 exhibited the highest biofilm-forming ability at various temperatures and media [phosphate buffered saline, nutrient broth (NB), and NB containing 15% sodium chloride]. At 25°C and 30°C, KS3, KS6, and KS8 showed higher biofilm-forming ability than S. aureus ATCC 29213. The antimicrobial resistance of the isolates was evaluated using the VITEK^® 2 system; most isolates were resistant to marbofloxacin and nitrofurantoin (both 9/9, 100%), followed by enrofloxacin (7/9, 77.8%). Five of the nine isolates (5/9, 55.6%) showed multidrug resistance. Our study reports the abilities of K. salsicia to grow in the presence of high salt concentrations and at relatively low temperatures, along with its multidrug resistance and tendency to form biofilms.

Examination of the microbiota of normal cow milk using MinIONTM nanopore sequencing

The aim of this study was to evaluate the microbiota of normal milk in dairy cows and their relationship with host factors, such as the age of the cow (Age), somatic cell counts in milk (SCCs), and days in milk (DIM). We investigated 48 milk samples from 22 cows with no systemic or local clinical signs using MinION^TM nanopore sequencing for a 16S rRNA gene amplicon. Bacterial richness was positively correlated with the DIM (P=0.043), and both the Shannon-Wiener Index and Simpson’s Index, which are metrics of alpha-diversity, were also significantly positively correlated with the SCC (P<0.001). The composition ratios of both Actinobacteria at the phylum level and Kocuria spp. at the genus level in the milk microbiota were significantly correlated with the SCC (P<0.001 and P<0.001, respectively). In the beta-diversity test, the one-way analysis of similarities test showed a significant difference (P=0.0051) between the low- and high-SCC groups. This study clarified that the composition of the normal milk microbiota in this herd was related to the SCC. It also raised the possibility of variations in bacterial genera in the normal milk microbiota between the low- and high-SCC groups. However, to clarify the actual condition of the milk microbiota and to elucidate the relationship with the SCC, it is necessary to perform further analyses taking into account not only the relative abundance, but also the absolute abundance of microbes.

A Rare Case of Pediatric Central Venous Catheter-Related Bloodstream Infection With Kocuria Varians

Cases of central line blood infections caused by Kocuria spp. are limited in the literature. Most of those infections have been detected in hospitalized patients with severe underlying disease or those with implanted catheters or with suppressed immunity. They are usually non-pathogenic in humans, but few cases of opportunistic infections in adult and pediatric populations have been reported. They can be serious in certain occasions. So treating physicians should not underestimate or ignore the significance of the infection with these bacteria.

We report a rare case of central venous catheter (CVC) infection associated with Kocuriavarians, which was successfully treated with CVC salvage.

Clinical Features and Outcomes of Kocuria Keratitis and Comparison With Coagulase-Negative Staphylococci Keratitis

PURPOSE

To describe the clinical features and outcomes of Kocuria keratitis and to compare the same with those of Coagulase-negative Staphylococcal (CoNS) keratitis.

METHODS

Medical records of cases with microbiologically proven Kocuria keratitis, seen from January 2011 to December 2017 were reviewed. The data related to predisposing factors, clinical characteristics, antibiotic susceptibility, and the treatment and their outcomes were collected. These parameters were also compared with those of consecutive patients with CoNS keratitis.

RESULTS

Medical records of 23 patients (n = 23 eyes) with Kocuria keratitis were reviewed, and after exclusion of 6 mixed infections, 17 cases with only Kocuria infection were analysed. The median visual acuity at presentation was finger counting 0.5 m [LogMAR 2.00 (1.70-2.70)]. The ulcer was characterized by a central infiltrate (88.2%) involving the anterior stroma (58.8%) with an associated hypopyon (29.4%). Kocuria rosea was the most common species (47.8%). Ninety percent of the isolates identified were susceptible to vancomycin and ofloxacin. In 12 cases (70.6%), the ulcer resolved with the use of topical antibiotics alone in 52 (29-79) days, whereas 3 eyes were subjected to therapeutic penetrating keratoplasty. On comparing the 44 cases of CoNS keratitis, the demographics and the visual acuity at presentation were comparable. Both groups had a similar in presentation response with medical therapy (P, 0.48) and those requiring surgical intervention (P, 0.76).

CONCLUSION

Kocuria is a rare but potential cause of keratitis manifesting in the presence of a compromised ocular surface. Similar to CoNS, it has good clinical response with medical management.

Kocuria kristinae interface keratitis following deep anterior lamellar keratoplasty

A 21-year-old boy underwent deep anterior lamellar keratoplasty (DALK) for advanced keratoconus. Postoperatively, slit lamp examination revealed multiple foci of interface infiltrates. Medical therapy was non-responsive, and therefore, a repeat lamellar transplantation was done. Scrapings were taken from host stroma and under the surface of the initial graft. Microbiological examination, aided by VITEK-2, revealed the causative organism as Kocuria kristinae. The postoperative course was uneventful and at a 1-year follow-up, the graft was clear with no recurrence of infection. This case highlights the pathogenic potential of Kocuria species, which has previously been disregarded as a commensal or contaminant.

The Composition of the Microbiota in the Full-Term Fetal Gut and Amniotic Fluid: A Bovine Cesarean Section Study

The development of a healthy intestinal immune system requires early microbial exposure. However, it remains unclear whether microbial exposure already begins at the prenatal stage. Analysis of such low microbial biomass environments are challenging due to contamination issues. The aims of the current study were to assess the bacterial load and characterize the bacterial composition of the amniotic fluid and meconium of full-term calves, leading to a better knowledge of prenatal bacterial seeding of the fetal intestine. Amniotic fluid and rectal meconium samples were collected during and immediately after elective cesarean section, performed in 25 Belgian Blue cow-calf couples. The samples were analyzed by qPCR, bacterial culture using GAM agar and 16S rRNA gene amplicon sequencing. To minimize the effects of contaminants, we included multiple technical controls and stringently filtered the 16S rRNA gene sequencing data to exclude putative contaminant sequences. The meconium samples contained a significantly higher amount of bacterial DNA than the negative controls and 5 of 24 samples contained culturable bacteria. In the amniotic fluid, the amount of bacterial DNA was not significantly different from the negative controls and all samples were culture negative. Bacterial sequences were identified in both sample types and were primarily of phyla Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria, with some individual variation. We conclude that most calves encounter in utero maternal-fetal transmission of bacterial DNA, but the amount of bacterial DNA is low and viable bacteria are rare.

Analysis of Kytococcus sedentarius Strain Isolated from a Dehumidifier Operating in a University Lecture Theatre: Systems for Aerobic Respiration, Resisting Osmotic Stress, and Sensing Nitric Oxide

A strain of Kytococcus sedentarius was isolated from a dehumidifier operating in a university lecture theatre. Genome analysis and phenotypic characterisation showed that this strain, K. sedentarius MBB13, was a moderately halotolerant aerobe with a branched aerobic electron transport chain and genes that could contribute to erythromycin resistance. The major compatible solute was glycine betaine, with ectoine and proline being deployed at higher osmolarities. Actinobacteria possess multiple WhiB-like (Wbl) regulatory proteins, and K. sedentarius MBB13 has four (WhiB1, WhiB2, WhiB3, and WhiB7). Wbls are iron-sulfur proteins that regulate gene expression through interactions with RNA polymerase sigma factors and/or other regulatory proteins. Bacterial two-hybrid analyses suggested that WhiB1 and WhiB2, but not WhiB3 and WhiB7, interact with the C-terminal domain of the major sigma factor, σA; no interaction was detected between any of the Wbl proteins and the only alternative sigma factors, σB, σH, or σJ. The interaction between σA and WhiB1 or WhiB2 was disrupted in a heterologous system under growth conditions that produce nitric oxide and the iron-sulfur clusters of the isolated WhiB1 and WhiB2 proteins reacted with nitric oxide. Thus, K. sedentarius strain exhibits the major phenotypic characteristics of the type strain and a comprehensive examination of the interactions between its four Wbl proteins and four sigma factors suggested that the Wbl proteins all operate through interaction with σA.

Repurposing of Tamoxifen Against the Oral Bacteria

Objectives

Tamoxifen (TAM), which is used for treating breast cancer, has exhibited another important function as an antimicrobial agent. The objective of this study is to investigate the antibacterial action of TAM against the bacteria present in the human oral cavity.

Materials and Methods

The bacteria present in the human oral cavity were isolated from healthy individuals. Different concentrations of TAM were tested against the isolated bacteria. Additionally, bactericidal and bacteriostatic effects of TAM were also determined.

Results

Out of 23 isolated bacteria, a greater number of Gram-positive bacteria were highly susceptible to the low concentrations of TAM than Gram-negative bacteria. Kytococcus sedentarius, which is Gram-positive bacterium, and Pseudomonas stutzeri, which is Gram-negative bacterium, needed a high minimum inhibitory concentration value of TAM (2.5 mg/mL) to be inhibited by TAM's bacteriostatic action. Resistance to TAM was also observed in three strains of Gram-positive and four strains of Gram-negative bacteria.

Conclusion

TAM has shown a potential antibacterial effect against the bacteria present in the oral cavity, especially against Gram-positive bacteria. This effect is mostly bacteriostatic. This study also found bacterial resistance toward TAM.

Structural aspects of lesional and non-lesional skin microbiota reveal key community changes in leprosy patients from India

Although skin is the primary affected organ in Leprosy, the role of the skin microbiome in its pathogenesis is not well understood. Recent reports have shown that skin of leprosy patients (LP) harbours perturbed microbiota which grants inflammation and disease progression. Herein, we present the results of nested Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis (PCR-DGGE) which was initially performed for investigating the diversity of bacterial communities from lesional skin (LS) and non-lesional skin (NLS) sites of LP (n = 11). Further, we performed comprehensive analysis of 16S rRNA profiles corresponding to skin samples from participants (n = 90) located in two geographical locations i.e. Hyderabad and Miraj in India. The genus Staphylococcus was observed to be one of the representative bacteria characterizing healthy controls (HC; n = 30), which in contrast was underrepresented in skin microbiota of LP. Taxa affiliated to phyla Firmicutes and Proteobacteria were found to be signatures of HC and LS, respectively. Observed diversity level changes, shifts in core microbiota, and community network structure support the evident dysbiosis in normal skin microbiota due to leprosy. Insights obtained indicate the need for exploring skin microbiota modulation as a potential therapeutic option for leprosy.

Ionizing-radiation-resistant Kocuria rhizophila PT10 isolated from the Tunisian Sahara xerophyte Panicum turgidum: Polyphasic characterization and proteogenomic arsenal

A new strain belonging to the genus Kocuria, designed PT10, was isolated from irradiated roots of the xerophyte Panicum turgidum. Isolate PT10 is a Gram-positive, coccoid, aerobic and ionizing-radiation (IR)-resistant actinobacterium. PT10 has shown an ability to survive under extreme conditions, such as gamma irradiation, desiccation and high concentration of hydrogen peroxide. Phenotypic, chemotaxonomic and comparative genome analyses support the assignment of strain PT10 (LMG 31102 = DSM 108617) as Kocuria rhizophila. The complete genome sequence of PT10 consists of one chromosome (2,656,287 bps), with a 70.7% G + C content and comprises 2481 protein-coding sequences. A total of 1487 proteins were identified by LC-MS/MS profiling. In silico analyses revealed that the proteome of the oxidation-tolerant PT10 possesses several features explaining its IR-resistant phenotype and many adaptive pathways implicated in response to environmental pressures - desiccation, cold, reactive oxygen species and other stressors.

Kocuria kristinae infection associated with short bowel syndrome: A case report

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Only a few cases of K. kristinae infection have been reported in the literature.

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Patients with short bowel syndrome (SBS) have a risk of opportunistic infections.

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We report a rare case of K. kristinae infection associated with SBS.

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Patients with SBS require careful follow-up for opportunistic infections such as K. kristinae.

Introduction

Only a few cases of K. kristinae infection have been reported in the literature. Patients with short bowel syndrome have an increased risk of opportunistic infections due to decreased bowel immunity and the long-term central venous catheter placement. We report a rare case of K. kristinae infection associated with SBS requiring long-term central venous access port placement.

Presentation of case

A 70-year-old woman presented with fever of approximately 39 °C to our hospital for examination. She has undergone total hysterectomy and radiation therapy for cervical cancer 36 years ago. Five years ago, she developed multiple small bowel perforations, and a jejunostomy was constructed at the oral end of the perforation and approximately 110 cm from the ligament of Treitz because of the difficulty in dissecting the adhesion. She developed short bowel syndrome, and the central venous port was constructed four years ago due to poor enteral nutrition.

K. kristinae was detected in the central venous catheter tip and in two blood cultures. We administered intravenous vancomycin. After seven days of antibiotic treatment, both fever and inflammatory reaction improved, and the blood culture was negative. After 16 days of antibiotic treatment, we performed central venous port construction on the side opposite to the previous site.

Conclusion

Patients with short bowel syndrome have an increased risk of K. kristinae infections due to decreased bowel immunity and the long-term central venous port, and therefore, these patients should be followed up carefully.

Bacterial Biodiversity of Extra Virgin Olive Oils and Their Potential Biotechnological Exploitation

Bacterial diversity of 15 extra virgin olive oils, obtained from different Italian varieties, including Frantoio, Coratina, Bosana, and Semidana, was analyzed in this study. All bacterial isolates were genotyped using RAPD and REP-PCR method and grouped by means of cluster analyses. Sequencing of 16S rDNA of 51 isolates, representative of 36 clusters, led to the identification of Bacillus spp., Brevibacillus spp., Micrococcus spp., Staphylococcus spp., Pantoea spp., Kocuria spp., Lysinbacillus spp., and Lactobacillus spp., most of which reported for first time in olive oils. Phenotypic characterization of the 51 isolates, some of which ascribed to potentially probiotic species, indicate that two of them have beta-glucosidase activity while 37% present lipolytic activity. Preliminary evaluation of probiotic potential indicates that 31% of the isolates show biofilm formation ability, 29% acidic pH resistance, and 25% bile salt resistance. Finally, 29% of the isolates were sensitive to antibiotics while the remaining 71%, that include bacterial species well-recognized for their ability to disseminate resistance genes in the environment, showed a variable pattern of antibiotic resistance. The results obtained underline that microbial diversity of extra virgin olive oils represents an unexpected sink of microbial diversity and poses safety issues on the possible biotechnological exploitation of this microbial biodiversity.

Rare case report of infective endocarditis due to Kocuria kristinae in a patient with ventricular septal defect

Background

Infective endocarditis (IE) is an uncommon but life-threatening infection. It is commonly associated with diseased or damaged valves. Patients with congenital heart disease are more prone to getting IE than the general population. The typical organisms that cause IE include Staphylococcus, Coagulase-negative Staphylococcus, Streptococcus viridians and Enterococci. However, the importance of rare micro-organisms like Kocuria kristinae should not be underestimated especially when isolated from multiple blood cultures in patients suspected of IE.

Case presentation

We report a rare case of right-sided infective endocarditis due to K. kristinae in a young non-diabetic, non-addict female of low socioeconomic class who presented with undiagnosed fever for 1 year. She was investigated and treated for fever by several general practitioners without relief. Later on, she was diagnosed by a local cardiologist to have perimembranous ventricular septal defect with a small pulmonary valve vegetation. She was referred to a tertiary care cardiac hospital in Rawalpindi, Pakistan for further management. Transthoracic and transesophageal echocardiography confirmed IE secondary to preexisting congenital heart disease complicated with a small pulmonary vegetation. Her blood cultures yielded growth of K. kristanae, a rare micro-organism to cause IE. The patient responded to the antibiotic therapy.

Conclusion

Clinicians should have a high index of suspicion for K. kristanae IE as a possible cause of a prolonged fever especially in the presence of congenital heart disease. Antibiotic susceptibility is required for adequate therapy.

Whole-Genome Sequences of Five Strains of Kocuria rosea, NCTC2676, NCTC7514, NCTC7512, NCTC7528, and NCTC7511

Kocuria rosea is a Gram-positive coccus found in the environment and within normal human skin microbiota, and more recently, it has been potentially implicated as an opportunistic pathogen. Here, we describe the genome sequences of five strains of K. rosea (NCTC2676, NCTC7514, NCTC7512, NCTC7528, and NCTC7511).

Kocuria rosea is a Gram-positive coccus found in the environment and within normal human skin microbiota, and more recently, it has been potentially implicated as an opportunistic pathogen. Here, we describe the genome sequences of five strains of K. rosea (NCTC2676, NCTC7514, NCTC7512, NCTC7528, and NCTC7511).

Endocarditis bacteriana por Kocuria kristinae en un paciente inmunocompetente. Reporte de caso

Los miembros del género Kocuria corresponden a cocos Gram positivos ubicuos, generalmente inocuos y que hacen parte de la flora saprófita de un porcentaje importante de la población; ocasionalmente han sido descritos como los agentes responsables de patologías infecciosas, principalmente dentro del contexto de pacientes que concomitantemente cursan con enfermedades crónicas y estados de inmunosupresión. Son escasos los casos reportados como causa de endocarditis en pacientes inmunocompetentes a nivel global por especies de este género. Se expone el caso de una mujer inmunocompetente de 44 años, sin antecedentesde importancia, en quien solo el diagnóstico microbiológico permitió confirmar la presencia de Kocuria kristinae como agente causal de su endocarditis infecciosa; la literatura señala la dificultad existente al momento de diferenciar la endocarditis producida por Staphylococcus spp. versus Kocuria kristinae por su evolución clínica similar, indicando la importancia de la microbiología al momento de identificar y diagnosticar apropiadamente.

Evaluation of the complexity of indoor air in hospital wards based on PM2.5, real-time PCR, adenosine triphosphate bioluminescence assay, microbial culture and mass spectrometry

Background

The aim of this study was to establish a set of assessment methods suitable for evaluating the complex indoor environment of hospital wards and to ascertain the composition of bacteria and microbial ecology of hospital wards.

Methods

Colony-forming units (CFUs), PM2.5 detection, real-time PCR, and adenosine triphosphate (ATP) bioluminescence assay were employed to evaluate the complexity of indoor air in 18 wards of nine departments in a hospital and two student dormitories in a university. Subsequently, the microbial samples were quantified and identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS).

Results

Although the studied indices were relatively independent, the PM2.5 content was correlated with bacterial CFUs determined by passive sedimentation method, bacterial and fungal counts measured by real-time PCR, and ATP bioluminescence assay. The composition of microorganisms in the air of hospital wards differed from that in the air of student dormitories. The dominant genera in hospital wards were Staphylococcus (39.4%), Micrococcus (21.9%), Corynebacterium (11.7%), Kocuria (4.4%), Bacillus (2.9%), Streptococcus (1.6%), Moraxella (1.6%), and Enterococcus (1.3%), and the microbial ecology differed between Respiration Dept. III and other hospital departments. Additionally, 11.1 and 27.3% of bacteria in hospital wards and student dormitories were not identified, respectively.

Conclusions

Assessment of environmental quality of hospital wards should be based on comprehensive analysis with multiple indicators. There may be imbalances in the microbial diversity in the hospital wards, therefore, monitoring of the environmental quality of hospitals is important in the prevention of nosocomial infections.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-4249-z) contains supplementary material, which is available to authorized users.

Clinical presentations, management outcomes, and diagnostic dilemma in Kocuria endophthalmitis

AIM

To describe the clinical presentations and management outcomes of Kocuria endophthalmitis and discuss diagnostic dilemmas DESIGN: Retrospective interventional comparative case series INTERVENTION: Eight unilateral cases with culture-proven Kocuria endophthalmitis from January 2013 to December 2017 underwent vitrectomy/vitreous biopsy and intravitreal antibiotic with or without additional procedures. The undiluted vitreous was subjected to microbiologic evaluation.

MAIN OUTCOME MEASURES

The mean age at presentation, etiology, number of interventions, interval between inciting event and presentation, type of intravitreal antibiotic used, and anatomic and functional outcomes were reported. A favorable anatomic outcome was defined as preservation of the globe, absence of hypotony, attached retina, and absence of active inflammation at the last visit.

RESULTS

In the current series, there were five males and three females. The mean age at presentation was 31 ± 17.44 years (median 30 years). The inciting event was open globe injury in five cases and one case each following cataract surgery, microbial keratitis, and endogenous cause. Visual acuity was ≥ 20/400 in one case at presentation and ≥ 20/400 in three cases at the last visit. The species identified by Vitek 2, included Kocuria kristinae in three, K. rosea in four and K. varians in one. Follow-up period was 8.25 ± 8.24 months (median 6.5). Six cases (75%) had complete resolution of infection and inflammation at the last visit. Anatomic success was achieved in 75%.

CONCLUSIONS

Kocuria is a relatively rare cause of endophthalmitis often misdiagnosed as Staphylococcal endophthalmitis. Clinical presentation can be variable but favorable antibiotic susceptibility and appropriate timely management can result in acceptable visual and anatomic outcomes.

Molecular analysis of oral microflora in patients with primary Sjögren's syndrome by using high-throughput sequencing

Background

The objective of this study was to characterize the oral microflora profile of primary Sjögren's syndrome (pSS) patients, thereby revealing the connection between oral bacterial composition and dental caries, and to identify the "core microbiome" in the oral cavities of pSS patients and systemic healthy individuals by using a high-throughput sequencing technique.

Methods

Twenty-two pSS patients and 23 healthy controls were enrolled in this study. Their clinical data and oral rinse samples were collected. The V3-V4 hypervariable regions of the bacterial 16S rRNA gene of samples were amplified and analyzed by high-throughput sequencing on the Illumina Miseq PE300 platform.

Results

Both two groups were age- and sex-matched. There were significantly higher decayed, missing and filled teeth (DMFT) and decayed, missing and filled surfaces (DMFS) in the pSS group than in the control group (p < 0.01). Alpha diversity was depleted in pSS patients, compared with healthy controls (p < 0.01), while beta diversity between the two groups was not significantly different. Seven discriminative genera (LDA > 4) were found between the two groups in LEfSe (LDA Effect Size) analysis. The relative abundance of Veillonella in pSS patients was fourfold higher, while Actinomyces, Haemophilus, Neisseria, Rothia, Porphyromonas and Peptostreptococcus were significantly lower in pSS patients than in healthy controls. However, the correlation between Veillonella and DMFT/DMFS was not significant (p > 0.05). In Venn diagram analysis, nine genera shared by all samples of two groups, which comprised 71.88% and 67.64% in pSS patients and controls, respectively.

Discussion

These findings indicate a microbial dysbiosis in pSS patients; notably, Veillonella might be recognized as a biomarker in pSS patients. The core microbiome in pSS patients was similar to the systemic healthy population. These provide insight regarding advanced microbial prevention and treatment of severe dental caries in pSS patients. This study also provides basic data regarding microbiology in pSS.

Bacterial isolates exhibiting multidrug resistance, hemolytic activity, and high 16S rRNA gene similarity with well-known pathogens found in camel milk samples of Riyadh region

Customary consumption of unpasteurized milk by the population in the central Najed region of Saudi Arabia may pose a health risk. Therefore, 80 camel milk samples were collected aseptically from seven different stations of Riyadh region. The biochemical and microbiological properties of these milk samples were determined. Nutrient agar and brain heart infusion agar were used to determine mesophilic aerobic counts (MACs). The MAC in each mL of milk varied from 60 to 16 × 10⁴  CFU/mL on nutrient agar. Based on the colony morphology, 176 colonies were collected from different samples, and these isolates were de-replicated into 80 unique isolates using rep-PCR analysis. Surprisingly, the 16S rRNA sequence analysis of these strains revealed that more than one-third of the collected milk samples contained strains that share maximum sequence similarities with well-known pathogens, such as Brucella, Bacillus anthracis, Listeria monocytogenes, and MRSA. Furthermore, many strains exhibit 16S rRNA gene similarity with opportunistic pathogens such as Citrobacter freundii and Kytococcus schroeteri. Many strains exhibit β-hemolytic activity and resistant to six different antibiotics. Our study suggested that consumption of raw camel milk from this region constitutes a great health risk.

A Case of Community-acquired Bacteremic Empyema Caused by Kocuria kristinae

Kocuria kristinae, part of the normal flora of the skin and oral mucosa, is seldom reported as a human pathogen; infection is mostly associated with immunocompromised patients in healthcare facilities. Here, we describe the first case of bacteremic empyema caused by K. kristinae acquired from the community. K. kristinae was isolated from pleural effusion and two sets of peripheral blood samples drawn from two different sites. The empyema resolved after the insertion of a chest tube and intravenous administration of piperacillin-tazobactam and levofloxacin.

Maxillary Osteomyelitis Caused by Kocuria Species in a Patient Who Is on Long-Term Uncontrolled Use of Methylprednisolone

Uncontrolled use of medicines bring with it serious health problems. Long-term and uncontrolled use of steroids, without the supervision of a healthcare professional, may cause unexpected infections due to immunosuppression. The authors present a patient with maxillary osteomyelitis caused by Kocuria species in a 41-year-old male who has been receiving methylprednisolone without control for 1.5 years.

Kocuria massiliensis sp. nov, a new bacterial species isolated from a patient with foot osteomyelitis

Most of the species from the genus Kocuria are environmental or commensals of mammalian skin and oral bacteria, and had rarely been associated with human infection. However, recent reports showed an increase of the clinical role of these bacteria in human infectious diseases. Most of the cases occurred in hospitals and were device related. They included bacteremia, peritonitis, abscess, endocarditis and ocular infection. We here describe the main characteristics and the draft genome of Kocuria massiliensis sp. nov., strain P3598^T (CSURP3598), a new Kocuria species that caused foot osteomyelitis in a 78-year-old woman. The improvement of diagnostic tools for the identification of bacteria in microbiological laboratories, including MALDI-TOF MS and 16S rRNA sequencing, largely contributed to the emergence and to the expansion of the clinical spectrum of infections caused by Kocuria spp. To the best of our knowledge, we report here the first case of osteomyelitis with a bacterial species from the genus Kocuria.

Phylogenetic Analysis and Antimicrobial Profiles of Cultured Emerging Opportunistic Pathogens (Phyla Actinobacteria and Proteobacteria) Identified in Hot Springs

Hot spring water may harbour emerging waterborne opportunistic pathogens that can cause infections in humans. We have investigated the diversity and antimicrobial resistance of culturable emerging and opportunistic bacterial pathogens, in water and sediment of hot springs located in Limpopo, South Africa. Aerobic bacteria were cultured and identified using 16S ribosomal DNA (rDNA) gene sequencing. The presence of Legionella spp. was investigated using real-time polymerase chain reaction. Isolates were tested for resistance to ten antibiotics representing six different classes: β-lactam (carbenicillin), aminoglycosides (gentamycin, kanamycin, streptomycin), tetracycline, amphenicols (chloramphenicol, ceftriaxone), sulphonamides (co-trimoxazole) and quinolones (nalidixic acid, norfloxacin). Gram-positive Kocuria sp. and Arthrobacter sp. and gram-negative Cupriavidus sp., Ralstonia sp., Cronobacter sp., Tepidimonas sp., Hafnia sp. and Sphingomonas sp. were isolated, all recognised as emerging food-borne pathogens. Legionella spp. was not detected throughout the study. Isolates of Kocuria, Arthrobacter and Hafnia and an unknown species of the class Gammaproteobacteria were resistant to two antibiotics in different combinations of carbenicillin, ceftriaxone, nalidixic acid and chloramphenicol. Cronobacter sp. was sensitive to all ten antibiotics. This study suggests that hot springs are potential reservoirs for emerging opportunistic pathogens, including multiple antibiotic resistant strains, and highlights the presence of unknown populations of emerging and potential waterborne opportunistic pathogens in the environment.

Epidemiology and Outcomes of Kocuria Keratitis

OBJECTIVE

To determine the characteristics of infectious keratitis caused by Kocuria spp.

METHODS

Retrospective case series. Information included demographic data, medical history, risk factors associated with infectious keratitis, clinical characteristics, microbiological results and drug sensitivity, clinical course, management, and visual outcomes.

RESULTS

Eight patients were included (7 females and 1 male; mean age, 66.2 years; age range, 42-84 years). All patients presented risk factors for infectious complications, such as filamentous keratitis, dry eye, blepharitis, and persistent corneal edema. In all cases, ulcers were classified as severe. The infection resolved with medical treatment in one eye only. One case was treated with amniotic membrane graft. Two patients required keratoplasty (lamellar and penetrating), and one case needed sclerokeratoplasty. In three cases, the keratitis was severe enough to require evisceration. The final visual acuity ranged from 20/25 to no light perception.

CONCLUSIONS

Bacterial keratitis by Kocuria spp. is a rare infection that may have an unexpected clinical course and possible serious outcomes. This pathogen should be considered in patients with unusual clinical course. Local or systemic immune compromise in the genesis of the disease must also be taken into account, and ophthalmologists should be more suspicious in this vulnerable group of patients.

Native valve endocarditis caused by Kocuria rosea complicated by peripheral mycotic aneurysm in an elderly host

Infective endocarditis still remains a dreaded illness among treating physicians because of the disease course, its need for meticulous antibiotic management, complications, and overall morbidity. Peripheral mycotic aneurysms are a rarely reported complication of infective endocarditis. Mycotic aneurysms occur in about 5%-10% of cases of infective endocarditis, and most of them involve the intracranial vessels. Here, we report a case of native valve endocarditis in a 74-year-old man caused by Kocuria rosea. He presented with septic shock and acute kidney injury. His illness was complicated by a right popliteal artery mycotic aneurysm. He was treated with intravenous ceftriaxone and vancomycin. The mycotic aneurysm needed aneurysmectomy and anastomosis with a graft.

Peripherally inserted central catheter-related bloodstream infection caused by Kocuria marina in an elderly man

BACKGROUND

Kocuria species are Gram-positive, aerobic cocci, and members of the Micrcoccaceae family that are known to be opportunistic pathogens. Although there have been sporadic reports of infections caused by Kocuria species, little is known regarding their human pathogenicity and clinical characteristics.

CASE REPORT

We herein report a case of a peripherally inserted central catheter (PICC)-related bloodstream infection caused by Kocuria marina in a 90-year-old Japanese with multiple cancer. The patient, who was admitted due to adhesive intestinal obstruction, suddenly developed sepsis on day 29 following admission. Three sets of blood cultures and a culture of the PICC tip revealed the growth of Gram-positive cocci arranged in clusters. The patient improved quickly after treatment with an antimicrobial agent and catheter removal. The organism was identified as Kocuria varians using the MicroScan Walkaway system and K. varians/Kocuria rosea with a 99.7% probability using an API Staph system. However, 16S rRNA gene sequencing analysis identified the pathogen as K. marina.

CONCLUSION

Although K. marina is a rare pathogen, physicians should consider it in case of catheter-related infections in patients with serious underlying conditions. As commercial identification systems can misidentify species within the Kocuria genus, the use of genomic methods such as 16S rRNA sequencing and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry may be useful for the precise identification of Kocuria to the species level.

Central Venous Catheter-Related Bloodstream Infection with Kocuria kristinae in a Patient with Propionic Acidemia

Kocuria kristinae is a catalase-positive, coagulase-negative, Gram-positive coccus found in the environment and in normal skin and mucosa in humans; however, it is rarely isolated from clinical specimens and is considered a nonpathogenic bacterium. We describe a case of catheter-related bacteremia due to K. kristinae in a young adult with propionic acidemia undergoing periodic hemodialysis. The patient had a central venous catheter implanted for total parenteral nutrition approximately 6 months prior to the onset of symptoms because of repeated acute pancreatitis. K. kristinae was isolated from two sets of blood cultures collected from the catheter. Vancomycin followed by cefazolin for 16 days and 5-day ethanol lock therapy successfully eradicated the K. kristinae bacteremia. Although human infections with this organism appear to be rare and are sometimes considered to result from contamination, physicians should not underestimate its significance when it is isolated in clinical specimens.

Bacteremia Caused by Kocuria kristinae from Egypt: Are There More? A Case Report and Review of the Literature

Kocuria kristinae is opportunistic Gram-positive cocci from the family Micrococcaceae. It is usually considered part of the normal flora that rarely is isolated from clinical specimens. Here, we report a case of Kocuria kristinae bacteremia; to the best of our knowledge, this is the first report from Egypt.

Emerging Bacterial Infection: Identification and Clinical Significance of Kocuria Species

Recently there have been reports of gram-positive cocci which are morphologically similar to both Staphylococci and the Micrococci. These bacteria have been identified as Kocuria species with the help of automated identification system and other molecular methods including 16S rRNA (ribosomal ribonucleic acid) evaluation. Kocuria belongs to the family Micrococcaceae which also includes Staphylococcus species and Micrococcus species. Isolation and clinical significance of these bacteria from human specimens warrant great caution as it does not necessarily confirm infection due to their ubiquitous presence, and as a normal flora of skin and mucous membranes in human and animals. Most clinical microbiology laboratories ignore such bacteria as laboratory and specimen contaminants. With increasing reports of infections associated with these bacteria, it is now important for clinical microbiologists to identify and enumerate the virulence and antibiotic susceptibility patterns of such bacteria and assist clinicians in improving the patient care and management. We review the occurrence and clinical significance of Kocuria species.