Kodamaea ohmeri as an Emerging Human Pathogen: A Review and Update

Background:Kodamaea ohmeri, previously known as Pichia ohmeri or Yamadazyma ohmeri, has been regarded as an emerging human pathogen in recent decades, and has caused various types of infections with high mortality. This study systematically reviewed all the published cases of K. ohmeri infection, aiming to have a better understanding of the clinical and epidemiological characteristics of the organism.Methods: All the published literature (as of March 31, 2021) on K. ohmeri, in four databases: PubMed, Embase, Web of Science, and CNKI, were systematically reviewed to select appropriate studies for summarizing the demographic information, clinical and microbiological characteristics of relevant infections.Results: A total of 51 studies involving 67 patients were included for final analysis, including 49 sporadic cases and two clusters of outbreaks. Neonates and the elderly constituted the majority of patients, and fungemia was the dominant infection type. Comorbidities (like malignancy, diabetes, and rheumatism), invasive operations, previous antibiotic use and prematurity, were commonly described in patients. Gene sequencing and broth microdilution method, were the most reliable way for the identification and antifungal susceptibility testing of K. ohmeri, respectively. Amphotericin B and fluconazole were the commonest antifungal therapies administered. The calculated mortality rates for K. ohmeri infection was higher than that of common candidemia.Conclusion: In this study, we systematically reviewed the epidemiology, clinical characteristics, microbiological features, treatment, and outcomes, of all the published cases on K. ohmeri. Early recognition and increased awareness of K. ohmeri as an emerging human pathogen by clinicians and microbiologists is important for effective management of this organism.

Microbiological Profile and Sensitivity Data among the Neonatal Population from a Tertiary Care Hospital in South India

Background: Sepsis is one of the most common causes of mortality and morbidity among neonates. The prevalence of microorganisms varies with regions, and the sensitivity pattern also changes over time. Aim: To study the prevalence of various microorganisms and their sensitivity pattern among the neonatal population in a tertiary care hospital in South India. Methods: This was a retrospective descriptive study. We screened the records of all neonates admitted to the hospital during a period starting from January 1st, 2016, to September 30th, 2018. The details of the patients with any sterile body fluids showing microbial growth were collected. Descriptive analysis was done using IBM SPSS version 20. Results: There were 77 organisms isolated during the study period, with the majority among outborn babies. Seventy-two isolates were from blood, two from CSF and urine, with one from the central line. The most common organism was Klebsiella (22%), followed by Burkholderia cepacia (12%), Staphylococcus aureus (9%), and Streptococcus agalactiae (7%). 9% of the organisms were fungus, with the most common being Kodamaea Ohmeri. Among the antibiotics tested for sensitivity, Meropenem had the maximum sensitivity ratio (84%), followed by Co-trimoxazole (83%) and Vancomycin (82%). Piperacillin tazobactam sensitivity was only 56%, and Ciprofloxacin was sensitive in 65% of cases. Most (6 out of 7) of the fungal isolates were sensitive to fluconazole. Conclusions: Klebsiella remains to be the most common organism causing severe infection in young infants. Worrying rise in the incidence of uncommon organisms (like Kodamaea Ohmeri, GBS, Burkholderia) and carbapenem resistance was noted. It is, therefore, essential to update the antibiotic policy of the neonatal units on a timely basis.

Presencia de la levadura Kodamaea ohmeri en escarabajos Aethina tumida (Coleoptera: Nitidulidae) colectados de colonias de abeja melífera africanizada en dos apiarios en Yucatán, México

Aethina tumida (Coleoptera: Nitidulidae), commonly known as the Small Hive Beetle (SHB), is becoming a significant pest in the beekeeping industry outside of its natural distribution range. In Mexico, recent reports indicate that the SHB is distributed throughout the Yucatan peninsula. The invasion of honey bee colonies by SHB it is mainly chemically mediated by volatiles produced by the yeast Kodamaea ohmeri which is regarded as a secondary symbiont of the SHB. It was analyzed the presence of this yeast in honey bee colonies of Yucatan based on the premise that symbionts are often conjointly distributed with their hosts, therefore the presence of K. ohmeri in hives will be closely associated with the presence of SHB. In managed Africanized honey bee (AHB) colonies, yeasts associated with adult beetles were isolated and identified and the results show that the SHB together with their associated yeast, K. ohmeri, have invaded AHB colonies in Yucatan. It was also reported the presence of yeasts other than K. ohmeri associated with SHB that for the first time are recorded in a geographical region where they had not been recorded before.

A Catheter-Related Bloodstream Infection Caused by the Yeast Kodamaea ohmeri

Catheter-related bloodstream infections caused by Kodamaea ohmeri are generally not considered due to the relative scarcity of reported cases. This is a case of an 85-year-old man with poorly controlled diabetes mellitus who was initially admitted to our hospital for diabetic ketoacidosis. An internal jugular catheter was inserted as part of the initial management. A week later the patient developed a temperature spike and a yeast identified as Kodamaea ohmeri by ID 32 C (bioMérieux, France) was isolated from both his central and peripheral blood cultures. The catheter was removed and the patient was treated with fluconazole despite the organism’s relatively high minimum inhibitory concentration (2 μg/mL) to this antifungal. The fungemia resolved following a 2-weeks course of fluconazole.

Assaying the effect of yeasts on growth of fungi associated with disease

Background Pathogenic fungi often cause serious infections mainly in immunocompromised persons. The number of infections caused by the non-albicans Candida or other species has significantly increased over the last years. These infections present a major challenge in the health sector because these pathogenic fungi have strong virulence and often show resistance to the commonly used antifungal treatments. To solve the problems caused by the drug resistant pathogenic fungi, it is necessary to find new antifungal agents and their sources. The aim of this study was to give evidence that yeasts can effectively fight against strains which belong to pathogenic fungi and reveal those yeasts which are able to inhibit growth of Kodamaea ohmeri, Pichia kudriavzevii, Naganishia albida or Candida tropicalis. Furthermore, we wanted to determine the effects of certain culturing factors on the growth inhibition. Results Our screening revealed that although the strains belonging to pathogenic species were much more tolerant to the yeast-produced bioactive agents than the non-disease-associated yeasts, growth of Kodamaea ohmeri and Candida tropicalis could be inhibited by Metschnikowia andauensis, while Naganishia albida could be controlled by Pichia anomala or Candida tropicalis. Our data proved that the experimental circumstances could have a serious impact on the inhibitory capacity of the yeasts. Appearance of inhibition strongly depended on media, pH and temperature. Our data also shed some light on the fact that Pichia kudriavzevii must have high natural resistance to the yeast-produced agents, while other species, such as Saccharomycopsis crataegensis belonged to the easily inhibitable species. Conclusions Our study suggests that yeast-produced bioactive agents could be potential growth inhibitory agents against the disease-associated fungi and yeasts can also contribute to alternative approaches to combat against pathogenic fungi. Our data revealed an important role of the culturing factors in inhibition and pointed to the complex nature of antagonism.