Multidrug-resistant Trichosporon species: underestimated fungal pathogens posing imminent threats in clinical settings

The stimulation of the immune response to prevent the progression of an infection may be an adjuvant to antimicrobial treatment. Here, we aimed to evaluate the efficacy of lysophosphatidylcholine (LPC) treatment in combination with colistin in murine experimental models of severe infections by Acinetobacter baumannii. We used the A. baumannii Ab9 strain, susceptible to colistin and most of the antibiotics used in clinical settings, and the A. baumannii Ab186 strain, susceptible to colistin but presenting a multidrug-resistant (MDR) pattern. The therapeutic efficacies of one and two LPC doses (25 mg/kg/d) and colistin (20 mg/kg/8 h), alone or in combination, were assessed against Ab9 and Ab186 in murine peritoneal sepsis and pneumonia models. One and two LPC doses combined with colistin and colistin monotherapy enhanced Ab9 and Ab186 clearance from spleen, lungs and blood and reduced mice mortality compared with those of the non-treated mice group in both experimental models. Moreover, one and two LPC doses reduced the bacterial concentration in tissues and blood in both models and increased mice survival in the peritoneal sepsis model for both strains compared with those of the colistin monotherapy group. LPC used as an adjuvant of colistin treatment may be helpful to reduce the severity and the resolution of the MDR A. baumannii infection.

Download Full-text

Virus Infection of Aspergillus fumigatus Compromises the Fungus in Intermicrobial Competition

Viruses ◽

10.3390/v13040686 ◽

2021 ◽

Vol 13 (4) ◽

pp. 686

Author(s):

Hasan Nazik ◽

Ioly Kotta-Loizou ◽

Gabriele Sass ◽

Robert H. A. Coutts ◽

David A. Stevens

Keyword(s):

Virus Infection ◽

Aspergillus Fumigatus ◽

Stress Responses ◽

Fungal Pathogens ◽

Clinical Settings ◽

Virus Infections ◽

Fungal Strains ◽

Common Reference ◽

Strain Virus ◽

Free Strain

Aspergillus and Pseudomonas compete in nature, and are the commonest bacterial and fungal pathogens in some clinical settings, such as the cystic fibrosis lung. Virus infections of fungi occur naturally. Effects on fungal physiology need delineation. A common reference Aspergillus fumigatus strain, long studied in two (of many) laboratories, was found infected with the AfuPmV-1 virus. One isolate was cured of virus, producing a virus-free strain. Virus from the infected strain was purified and used to re-infect three subcultures of the virus-free fungus, producing six fungal strains, otherwise isogenic. They were studied in intermicrobial competition with Pseudomonasaeruginosa. Pseudomonas culture filtrates inhibited forming or preformed Aspergillus biofilm from infected strains to a greater extent, also seen when Pseudomonas volatiles were assayed on Aspergillus. Purified iron-chelating Pseudomonas molecules, known inhibitors of Aspergillus biofilm, reproduced these differences. Iron, a stimulus of Aspergillus, enhanced the virus-free fungus, compared to infected. All infected fungal strains behaved similarly in assays. We show an important consequence of virus infection, a weakening in intermicrobial competition. Viral infection may affect the outcome of bacterial–fungal competition in nature and patients. We suggest that this occurs via alteration in fungal stress responses, the mechanism best delineated here is a result of virus-induced altered Aspergillus iron metabolism.

Download Full-text

Effectiveness of antimicrobial hospital curtains on reducing bacterial contamination—A multicenter study

Infection Control and Hospital Epidemiology ◽

10.1017/ice.2018.315 ◽

2018 ◽

Vol 40 (2) ◽

pp. 164-170 ◽

Cited By ~ 1

Author(s):

Shik Luk ◽

Viola Chi Ying Chow ◽

Kelvin Chung Ho Yu ◽

Enoch Know Hsu ◽

Ngai Chong Tsang ◽

...

Keyword(s):

Multicenter Study ◽

Bacterial Contamination ◽

Indirect Costs ◽

Multidrug Resistant ◽

Clinical Settings ◽

Carbapenem Resistant ◽

Colony Forming Units ◽

Multidrug Resistant Organisms ◽

Bed Days

AbstractObjectiveTo determine the efficacy of 2 types of antimicrobial privacy curtains in clinical settings and the costs involved in replacing standard curtains with antimicrobial curtains.DesignA prospective, open-labeled, multicenter study with a follow-up duration of 6 months.SettingThis study included 12 rooms of patients with multidrug-resistant organisms (MDROs) (668 patient bed days) and 10 cubicles (8,839 patient bed days) in the medical, surgical, neurosurgical, orthopedics, and rehabilitation units of 10 hospitals.MethodCulture samples were collected from curtain surfaces twice a week for 2 weeks, followed by weekly intervals.ResultsWith a median hanging time of 173 days, antimicrobial curtain B (quaternary ammonium chlorides [QAC] plus polyorganosiloxane) was highly effective in reducing the bioburden (colony-forming units/100 cm2, 1 vs 57; P < .001) compared with the standard curtain. The percentages of MDRO contamination were also significantly lower on antimicrobial curtain B than the standard curtain: methicillin-resistant Staphylococcus aureus, 0.5% vs 24% (P < .001); carbapenem-resistant Acinetobacter spp, 0.2% vs 22.1% (P < .001); multidrug-resistant Acinetobacter spp, 0% vs 13.2% (P < .001). Notably, the median time to first contamination by MDROs was 27.6 times longer for antimicrobial curtain B than for the standard curtain (138 days vs 5 days; P = .001).ConclusionsAntimicrobial curtain B (QAC plus polyorganosiloxane) but not antimicrobial curtain A (built-in silver) effectively reduced the microbial burden and MDRO contamination compared with the standard curtain, even after extended use in an active clinical setting. The antimicrobial curtain provided an opportunity to avert indirect costs related to curtain changing and laundering in addition to improving patient safety.

Download Full-text

The Face of Hypervirulent Klebsiella Pneumoniae (hvKp) Isolated from Clinical Samples of Two Iranian Teaching Hospitals

10.21203/rs.3.rs-589877/v1 ◽

2021 ◽

Author(s):

Rahimeh Sanikhani ◽

Mohammad Moeinirad ◽

Hamid Solgi ◽

Azar Haddadi ◽

Fereshteh Shahcheraghi ◽

...

Keyword(s):

Molecular Markers ◽

Klebsiella Pneumoniae ◽

Multidrug Resistant ◽

Teaching Hospitals ◽

Clinical Samples ◽

Clinical Settings ◽

Urgent Problem ◽

Clonal Relatedness ◽

The Face ◽

Global Concern

Abstract Hypervirulent Klebsiella pneumoniae (hvKp) has emerged as a pathogen of global concern. In this study, both phenotypic and genotypic tests were used to detect hvKp. Antimicrobial resistance profiles and clonal relatedness of clinical isolates were also determined. We found that 62.6% of the isolates were tellurite resistant and among them iucA or iutA or peg344 as hvKp molecular markers, were positive. The blaSHV (81.4%), followed by blaCTX−M15 (75.5%) and blaTEM (67.6%), blaOXA−48 (33.7%), blaNDM−1 (32.3%) were detected, while blaKPC−1 was not present in any hvKp isolates. It was found that the majority of hvKp isolates belonged to capsular serotype K20 and ompK36 group C, which is related to CG23 (e.g. ST23). A high percentage of multidrug-resistant hvKp (MDR-hvKp) and high resistance to imipenem (66%) indicated that there is an urgent problem that should be addressed in the clinical settings.

Download Full-text

First reported case series of Candida krusei peritonitis secondary to a perforated viscus

International Surgery Journal ◽

10.18203/2349-2902.isj20204148 ◽

2020 ◽

Vol 7 (10) ◽

pp. 3428

Author(s):

Pearl Wong ◽

Rafael Gaszynski ◽

Andrew Gray ◽

Mark Ghali ◽

Yasser Farooque ◽

...

Keyword(s):

Fungal Pathogens ◽

Case Series ◽

Abdominal Sepsis ◽

Multidrug Resistant ◽

Multiple Organ ◽

Candida Krusei ◽

Tertiary Peritonitis ◽

Early Use ◽

Candida Peritonitis ◽

Perforated Viscus

Candida peritonitis is associated with high mortality and multiple organ failure. With an evolving epidemiology of candidaemia indicating an increasing prevalence of rare Candida species worldwide, consideration of multidrug-resistant fungal pathogens as a cause of abdominal sepsis is paramount. We report three cases of Candida krusei as a cause of secondary and tertiary peritonitis. These cases highlight that the early use of an echinocandin class antifungal in patients not responding to standard regimens warrants consideration.

Download Full-text

Emerging Fungal Infections: New Patients, New Patterns, and New Pathogens

Journal of Fungi ◽

10.3390/jof5030067 ◽

2019 ◽

Vol 5 (3) ◽

pp. 67 ◽

Cited By ~ 36

Author(s):

Friedman ◽

Schwartz

Keyword(s):

North America ◽

Fungal Pathogens ◽

Fungal Infections ◽

Trichophyton Mentagrophytes ◽

Invasive Fungal Disease ◽

Multidrug Resistant ◽

Antifungal Prophylaxis ◽

Candida Spp ◽

Sporothrix Brasiliensis ◽

Emerging Fungal Infections

: The landscape of clinical mycology is constantly changing. New therapies for malignant and autoimmune diseases have led to new risk factors for unusual mycoses. Invasive candidiasis is increasingly caused by non-albicans Candida spp., including C. auris, a multidrug-resistant yeast with the potential for nosocomial transmission that has rapidly spread globally. The use of mould-active antifungal prophylaxis in patients with cancer or transplantation has decreased the incidence of invasive fungal disease, but shifted the balance of mould disease in these patients to those from non-fumigatus Aspergillus species, Mucorales, and Scedosporium/Lomentospora spp. The agricultural application of triazole pesticides has driven an emergence of azole-resistant A. fumigatus in environmental and clinical isolates. The widespread use of topical antifungals with corticosteroids in India has resulted in Trichophyton mentagrophytes causing recalcitrant dermatophytosis. New dimorphic fungal pathogens have emerged, including Emergomyces, which cause disseminated mycoses globally, primarily in HIV infected patients, and Blastomyces helicus and B. percursus, causes of atypical blastomycosis in western parts of North America and in Africa, respectively. In North America, regions of geographic risk for coccidioidomycosis, histoplasmosis, and blastomycosis have expanded, possibly related to climate change. In Brazil, zoonotic sporotrichosis caused by Sporothrix brasiliensis has emerged as an important disease of felines and people.

Download Full-text

Identification, Typing, Antifungal Resistance Profile, and Biofilm Formation ofCandida albicansIsolates from Lebanese Hospital Patients

BioMed Research International ◽

10.1155/2014/931372 ◽

2014 ◽

Vol 2014 ◽

pp. 1-10 ◽

Cited By ~ 13

Author(s):

Ibrahim Bitar ◽

Roy A. Khalaf ◽

Houda Harastani ◽

Sima Tokajian

Keyword(s):

Biofilm Formation ◽

Fungal Pathogens ◽

Recurrent Infection ◽

Multidrug Resistant ◽

Antifungal Resistance ◽

Drug Resistant ◽

Treatment Regimens ◽

Evolutionary Relatedness ◽

Resistant Strains ◽

Drug Resistant Strains

As leading opportunistic fungal pathogens identification and subtyping ofCandidaspecies are crucial in recognizing outbreaks of infection, recognizing particularly virulent strains, and detecting the emergence of drug resistant strains. In this study our objective was to compare identification ofCandida albicansby the hospitals through the use of conventional versus identification based on the ITS (Internal Transcribed Spacer) and to assess biofilm forming capabilities, drug resistance patterns and correlate these with MLST typing. ITS typing revealed a 21.2% hospital misidentification rate. Multidrug resistance to three drugs out of four tested was detected within 25% of the isolates raising concerns about the followed treatment regimens. Drug resistant strains as well as biofilm formers were phylogenetically related, with some isolates with significant biofilm forming capabilities being correlated to those that were multidrug resistant. Such isolates were grouped closely together in a neighbor-joining tree generated by MLST typing indicating phylogenetic relatedness, microevolution, or recurrent infection. In conclusion, this pilot study gives much needed insight concerningC. albicansisolates circulating in Lebanese hospitals and is the first study of its kind correlating biofilm formation, antifungal resistance, and evolutionary relatedness.

Download Full-text

Global analyses imply that Stenotrophomonas maltophilia biofilms are phenotypically highly diverse despite a common transcriptome profile

10.5194/biofilms9-73 ◽

2020 ◽

Author(s):

Ifey Alio ◽

Mirja Gudzuhn ◽

Marie Schölmerich ◽

Pablo Pérez García ◽

Christel Vollstedt ◽

...

Keyword(s):

Biofilm Formation ◽

Stenotrophomonas Maltophilia ◽

Phenotypic Variability ◽

Multidrug Resistant ◽

Clinical Isolates ◽

Clinical Settings ◽

Data Set ◽

Specific Level ◽

Key Factor ◽

Fermentative Growth

Stenotrophomonas maltophilia is one of the most frequently isolated multidrug resistant opportunistic pathogens. It contributes to disease progression in cystic fibrosis patients and is found in wounds, other infected tissues and on catheter surfaces. Only little is known on key processes linked to biofilm formation of S. maltophilia on a broader basis. Thus the aim of this study was the identification of key processes involved in biofilm formation of S. maltophilia on a global level. Therefore, we analyzed biofilm profiles of 300 globally collected clinical and environmental isolates of the main and recently identified lineages Sgn3, Sgn4 and Sm2 - Sm18 (Groeschel et al., 2020). These data together with the 3D structural analysis of a subset of clinical 40 clinical isolates revealed an unexpectedly high phenotypic variability on a strain specific level. Further transcriptome analysis of seven clinical isolates using biofilm grown cells identified a set of 106 shared and coexpressed genes and roughly 30-35 strain-specific genes. Based on these findings S. maltophilia employs a mostly fermentative growth modus under the biofilm conditions and uptake of iron, phosphorous and other metals appears to be of high relevance. Surprisingly, the transcriptome profiles of biofilm versus planktonic cells revealed that only 8.6% of all genes were differentially regulated when both conditions were compared.&#160; This implies that only relatively few genes contribute to the change from planktonic to biofilm life style. Thereby iron uptake appears to be a key factor involved in this metabolic shift. The transcriptome data generated in this study together with the phenotypic and metabolic analysis represent so far the largest data set on S. maltophilia biofilm versus planktonic grown cells. This study now lays the foundation for the identification of new strategies in fighting S. maltophilia infections in clinical settings. Ref: &#160;Gr&#246;schel et al., 2020 ,The phylogenetic landscape and nosocomial spread of the multidrug-resistant opportunist Stenotrophomonas maltophilia. Nature Commun. 2020 Apr 27;11(1):2044. doi: 10.1038/s41467-020-15123-0.

Download Full-text

The Widespread Multidrug-Resistant Serotype O12 Pseudomonas aeruginosa Clone Emerged through Concomitant Horizontal Transfer of Serotype Antigen and Antibiotic Resistance Gene Clusters

mBio ◽

10.1128/mbio.01396-15 ◽

2015 ◽

Vol 6 (5) ◽

Cited By ~ 21

Author(s):

Sandra Wingaard Thrane ◽

Véronique L. Taylor ◽

Luca Freschi ◽

Irena Kukavica-Ibrulj ◽

Brian Boyle ◽

...

Keyword(s):

Pseudomonas Aeruginosa ◽

Antibiotic Resistance ◽

Horizontal Transfer ◽

Core Genome ◽

Gene Clusters ◽

Multidrug Resistant ◽

Clinical Settings ◽

Content Type ◽

The Past ◽

Antibiotic Resistance Determinant

ABSTRACTThe O-specific antigen (OSA) inPseudomonas aeruginosalipopolysaccharide is highly varied by sugar identity, side chains, and bond between O-repeats. These differences classifiedP. aeruginosainto 20 distinct serotypes. In the past few decades, O12 has emerged as the predominant serotype in clinical settings and outbreaks. These serotype O12 isolates exhibit high levels of resistance to various classes of antibiotics. Here, we explore how theP. aeruginosaOSA biosynthesis gene clusters evolve in the population by investigating the association between the phylogenetic relationships among 83P. aeruginosastrains and their serotypes. While most serotypes were closely linked to the core genome phylogeny, we observed horizontal exchange of OSA biosynthesis genes among phylogenetically distinctP. aeruginosastrains. Specifically, we identified a “serotype island” ranging from 62 kb to 185 kb containing theP. aeruginosaO12 OSA gene cluster, an antibiotic resistance determinant (gyrAC248T), and other genes that have been transferred betweenP. aeruginosastrains with distinct core genome architectures. We showed that these genes were likely acquired from an O12 serotype strain that is closely related toP. aeruginosaPA7. Acquisition and recombination of the “serotype island” resulted in displacement of the native OSA gene cluster and expression of the O12 serotype in the recipients. Serotype switching by recombination has apparently occurred multiple times involving bacteria of various genomic backgrounds. In conclusion, serotype switching in combination with acquisition of an antibiotic resistance determinant most likely contributed to the dissemination of the O12 serotype in clinical settings.IMPORTANCEInfection rates in hospital settings by multidrug-resistant (MDR)Pseudomonas aeruginosaclones have increased during the past decades, and serotype O12 is predominant among these epidemic strains. It is not known why the MDR phenotype is associated with serotype O12 and how this clone type has emerged. This study shows that evolution of MDR O12 strains involved a switch from an ancestral O4 serotype to O12. Serotype switching was the result of horizontal transfer and genetic recombination of lipopolysaccharide (LPS) biosynthesis genes originating from an MDR taxonomic outlierP. aeruginosastrain. Moreover, the recombination event also resulted in acquisition of antibiotic resistance genes. These results impact on our understanding of MDR outbreak strain and serotype evolution and can potentially assist in better monitoring and prevention.

Download Full-text

The Face of Hypervirulent Klebsiella Pneumoniae (hvKp) Isolated from Clinical samples of Two Iranian Teaching Hospitals

10.21203/rs.3.rs-589877/v2 ◽

2021 ◽

Author(s):

Rahimeh Sanikhani ◽

Mohammad Moeinirad ◽

Hamid Solgi ◽

Azar Hadadi ◽

Fereshteh Shahcheraghi ◽

...

Keyword(s):

Molecular Markers ◽

Klebsiella Pneumoniae ◽

Multidrug Resistant ◽

Teaching Hospitals ◽

Clinical Samples ◽

Clinical Settings ◽

Urgent Problem ◽

Clonal Relatedness ◽

The Face ◽

Global Concern

Abstract Hypervirulent Klebsiella pneumoniae (hvKp) has emerged as a pathogen of global concern. In this study, both phenotypic and genotypic tests were used to detect hvKp. Antimicrobial resistance profiles and clonal relatedness of clinical isolates were also determined. We found that 62.6% of the isolates were tellurite resistant and among them iucA or iutA or peg344 as hvKp molecular markers, were positive. The blaSHV (81.4%), followed by blaCTX−M15 (75.5%) and blaTEM (67.6%), blaOXA−48 (33.7%), blaNDM−1 (32.3%) were detected, while blaKPC−1 was not present in any hvKp isolates. It was found that the majority of hvKp isolates belonged to capsular serotype K20 and ompK36 group C, which is related to CG23 (e.g. ST23). A high percentage of multidrug-resistant hvKp (MDR-hvKp) and high resistance to imipenem (66%) indicated that there is an urgent problem that should be addressed in the clinical settings.

Download Full-text