Candida auris Infection in a Meningococcal Septicemia Survivor, Poland.

BACKGROUND: Candida auris is an emerging pathogen that constitutes a serious global health threat. It is difficult to identify without specific approaches, and it can be misidentified with standard laboratory methods, what may lead to inappropriate management. CASE PRESENTATION: We report, probably the first in Poland, C. auris isolation from blood cultures and wound swabs of a young male following meningococcal septicaemia, in February 2019. The patient had been previously hospitalized in the United Arab Emirates. The isolate was rapidly identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry and therefore clinicians were promptly informed on the alert pathogen isolation. The targeted antifungal treatment was successful and infection control measures seemed effective. ITS-based identification and subsequent whole genome sequencing showed that the C. auris isolate belongs to South Asian lineage (clade I). CONCLUSIONS: C. auris is able to cause outbreaks in healthcare settings. Therefore, it is important to quickly identify C. auris isolates in hospital settings so that healthcare facilities can take proper precautions to limit its spread.

Ceftazidime/Avibactam and Other Commonly Used Antibiotics Activity Against Enterobacterales and Pseudomonas aeruginosa Isolated in Poland in 2015-2019.

Purpose: Infections caused by resistant Gram-negative bacteria are becoming increasingly common and now pose a serious public health threat worldwide, because they are difficult to treat due to few treatment options and they are associated with high morbidity and mortality. The combination of ceftazidime with the beta-lactamase inhibitor avibactam - seems to be the right choice in this situation. The aim of the study was to evaluate the activity of ceftazidime/avibactam and other commonly used antibiotics against Enterobacterales and Pseudomonas aeruginosa strains isolated within last years in Poland. Patients and Methods: This study analyzed the antibiotic susceptibility of 1607 Enterobacterales isolates and 543 nonfermenting P. aeruginosa strains collected between 2015 and 2019 in 4 medical laboratories participating in the ATLAS (Antimicrobial Testing Leadership And Surveillance) program in Poland. Unduplicated clinically significant Enterobacterales and P. aeruginosa strains were collected from patients with respiratory, skin and musculoskeletal, genitourinary, abdominal, bloodstream or other infections (ear, eye). Results: The ceftazidime/avibactam combination demonstrates the highest activity against Enterobacterales (98.9%), in both adults and children, including strains presenting MDR (multidrug-resistant) (97.5%) and ESBL (extended spectrum ß-lactamase) (96.3%) phenotypes. The activity of ceftazidime/avibactam increased to 100% when only MBL (metallo-ß-lactamase)-negative subset of Enterobacterales was considered. This combination also achieved the second highest activity result (89.3%) after colistin in P. aeruginosa, including isolates of MDR (65.9%) and carbapenem-resistant (CR) phenotypes (54.8%). When MBL-positive isolates were excluded, susceptibility rate of P. aeruginosa increased to 94.7%. It is worth to note that susceptibility of the examined P. aeruginosa strains to ceftazidime/avibactam was very high in children (93.3%), especially in a pediatric intensive care unit (94.2%). Conclusion: Enterobacterales and P. aeruginosa included in this analysis presented high susceptibility rates to ceftazidime/avibactam. Ceftazidime/avibactam showed the highest activity against Enterobacterales strains among all antibiotics studied, both for the total population as well as for MDR phenotype and ESBL phenotype. Ceftazidime/avibactam also achieved the second highest activity result against P. aeruginosa strains (including MDR and CR phenotypes). These results are much higher when excluding MBL-positive isolates that exhibit intrinsic resistance to ceftazidime/avibactam.

Carbapenem-Resistant Pseudomonas aeruginosa Strains-Distribution of the Essential Enzymatic Virulence Factors Genes.

Pseudomonas aeruginosa is one of the most commonly isolated bacteria from clinical specimens, with increasing isolation frequency in nosocomial infections. Herein, we investigated whether antimicrobial-resistant P. aeruginosa strains, e.g., metallo-beta-lactamase (MBL)-producing isolates, may possess a reduced number of virulence genes, resulting from appropriate genome management to adapt to a changing hospital environment. Hospital conditions, such as selective pressure, may lead to the replacement of virulence genes by antimicrobial resistance genes that are crucial to survive under current conditions. The study aimed to compare, using PCR, the frequency of the chosen enzymatic virulence factor genes (alkaline protease-aprA, elastase B-lasB, neuraminidases-nan1 and nan2, and both variants of phospholipase C-plcH and plcN) to MBL distribution among 107 non-duplicated carbapenem-resistant P. aeruginosa isolates. The gene encoding alkaline protease was noted with the highest frequency (100%), while the neuraminidase-1 gene was observed in 37.4% of the examined strains. The difference in lasB and nan1 prevalence amongst the MBL-positive and MBL-negative strains, was statistically significant. Although P. aeruginosa virulence is generally more likely determined by the complex regulation of the virulence gene expression, herein, we found differences in the prevalence of various virulence genes in MBL-producers.

Paradoxical growth effect of caspofungin on Candida spp. sessile cells not only at high drug concentrations.

According to the available literature, echinocandins display high anti-Candida spp. activity. Paradoxical growth (PG) of Candida spp. planktonic cells promoted by echinocandins is widely reported. Here we report on the ability of Candida spp. sessile cells to display PG when they are exposed to caspofungin in vitro, even at relatively low drug concentrations. Clinical significance of PG during echinocandin therapy of candidiasis remains uncertain. We assessed in vitro susceptibilities of Candida spp. sessile cells to caspofungin and analyzed the frequency of PG. The minimum inhibitory concentrations of caspofungin for sessile cells (SMICs) were determined for 70 clinical Candida spp. isolates (29 Candida albicans, 26 Candida parapsilosis, and 15 Candida glabrata isolates) and were defined as the lowest drug concentrations that resulted in at least 50% reduction in metabolic activity. PG was defined as a resurgence of growth (>50% of that in the drug-free growth control well) at drug concentrations above the MIC. The caspofungin SMICs ranged from ≤0.015 to >256 µg ml-1. We observed PG in 26.9-93.1% of isolates tested, depending on the Candida species and age of sessile cells. Antibiofilm activity of caspofungin is species-specific, and strongly strain-depending among C. albicans and C. parapsilosis isolates. Interestingly, PG was present also at relatively low caspofungin concentrations.

Fulminant mucormycosis after a traffic accident: a case report.

Mucormycosis is a rare fungal infection in immunocompetent patients, whereas in immunocompromised, it may be systemic and disseminated infection associated with high mortality. Mucormycosis is one of the most rapidly progressing and fulminant forms of fungal infections; Mucor circinelloides is rarely isolated species, also from immunocompromised patients. The reported case of mucormycosis after a traffic accident indicates that it may be the result of a contamination of wound by M. circinelloides coming from the environment. The fungal strain was identified by phenotypic methods and confirmed by molecular methods. Etest method was used for susceptibility testing of the fungal strain. No mycotoxins were detected in the analyzed sample. The infection was successfully treated with amphotericin B, but amputation of the lower limb was necessary.

In vitro activity of micafungin against biofilms of Candida albicans, Candida glabrata, and Candida parapsilosis at different stages of maturation.

Candida spp. is able to form a biofilm, which is considered resistant to the majority of antifungals used in medicine. The aim of this study was to evaluate the in vitro activity of micafungin against Candida spp. biofilms at different stages of their maturation (2, 6, and 24 h). We assessed the inhibitory effect of micafungin against 78 clinical isolates of Candida spp., growing as planktonic or sessile cells, by widely recommended broth microdilution method. The in vitro effect on sessile cells viability was evaluated by colorimetric reduction assay. All examined strains were susceptible or intermediate to micafungin when growing as planktonic cells. At the early stages of biofilm maturation, from 11 (39.3%) to 20 (100%), tested strains, depending on the species, exhibited sessile minimal inhibitory concentrations (SMICs) of micafungin at ≤ 2 mg/L. For 24-h-old Candida spp. biofilms, from 3 (10.7%) to 20 (100%) of the tested strains displayed SMICs of micafungin at ≤ 2 mg/L. Our findings confirm that micafungin exhibits high potential anti-Candida-biofilm activity. However, this effect does not comprise all Candida species and strains. All strains were susceptible or intermediate to micafungin when growing as planktonic cells, but for biofilms, micafungin displays species- and strain-specific activity. Paradoxical growth of C. albicans and C. parapsilosis was observed. Antifungal susceptibility testing of Candida spp. biofilms would be the best solution, but to date, no reference method is available. The strongest antibiofilm activity of micafungin is observed at early stages of biofilm formation. Possibly, micafungin could be considered as an effective agent for prevention of biofilm-associated candidiasis, especially catheter-related candidaemia.

The Prevalence of Exoenzyme S Gene in Multidrug-Sensitive and Multidrug-Resistant Pseudomonas aeruginosa Clinical Strains.

Pseudomonas aeruginosa rods are one of the most commonly isolated microorganisms from clinical specimens, usually responsible for nosocomial infections. Antibiotic-resistant P. aeruginosa strains may present reduced expression of virulence factors. This fact may be caused by appropriate genome management to adapt to changing conditions of the hospital environment. Virulence factors genes may be replaced by those crucial to survive, like antimicrobial resistance genes. The aim of this study was to evaluate, using PCR, the occurrence of exoenzyme S-coding gene (exoS) in two distinct groups of P. aeruginosa strains: 83 multidrug-sensitive (MDS) and 65 multidrug-resistant (MDR) isolates. ExoS gene was noted in 72 (48.7%) of the examined strains: 44 (53.0%) MDS and 28 (43.1%) MDR. The observed differences were not statistically significant (p = 0.1505). P. aeruginosa strains virulence is rather determined by the expression regulation of the possessed genes than the difference in genes frequency amongst strains with different antimicrobial susceptibility patterns.

In vitro effect of amphotericin B on Candida albicans, Candida glabrata and Candida parapsilosis biofilm formation.

Candida spp. biofilm is considered highly resistant to conventional antifungals. The aim of this study was to investigate the in vitro effect of amphotericin B on Candida spp. biofilms at different stages of maturation. We investigated the activity of amphotericin B against 78 clinical isolates of Candida spp., representing three species, growing as planktonic and sessile cells, by a widely accepted broth microdilution method. The in vitro effect on sessile cell viability was evaluated by MTT reduction assay. All examined strains were susceptible to amphotericin B when grown as free-living cells. At the early stages of biofilm maturation 96.7-100.0 % strains, depending on species, displayed amphotericin B sessile minimal inhibitory concentration (SMIC) ≤ 1 µg/mL. Mature Candida spp. biofilm of 32.1-90.0 % strains displayed amphotericin B SMIC ≤ 1 µg/mL. Based on these results, amphotericin B displays species- and strain-depending activity against Candida spp. biofilms.

[The species variety and drug susceptibility of fungi isolated from blood samples of patients of the Dr. A. Jurasz university hospital in Bydgoszcz in the years 2005-2008]. / Zróznicowanie gatunkowe i lekowrazliwosc grzybów wyosobnionych z krwi pacjentów szpitala uniwersyteckiego w Bydgoszczy w latach 2005-2008.

The aim of the study was retrospective analysis of the species variety and the drug susceptibility to antifungal drugs of fungal strains isolated form blood samples of patients of the dr. A. Jurasz University Hospital in Bydgoszcz, in the years 2005-2008. A total of 79 strains patients was isolated from 68 during these four years. Above 96% strains belong to Candida spp., while three strains--to Cryptococcus spp. Almost 56% strains were isolated from more than one blood sample. In the first three years of analysis gradual increase of the number of cultured strains was observed, but in 2008 the decrease was noticed. The majority of strains were obtained from patients of the Anesthesiology and Intensive Care Clinic (32,9%) and the Pediatrics, Hematology and Oncology Clinic (24,1%). Every year the same species were the most frequently cultered: C. albicans, C. parapsilosis i C. glabrata. C albicans was found as the dominant species each year. Almost 32% of strains were isolated from blood samples obtained by peripheral insertion of a needle and by catheter as well. C. parapsilosis was the most frequently isolated species from those cases (48,0%). Among non-C. albicans species there were higher percentages of strains resistant to flucytosine, amphotericin B and fluconazole observed.

[The influence of cell surface hydrophobicity Candida sp. on biofilm formation on different biomaterials]. / Wplyw wlasciwosci hydrofobowych Candida sp. na zdolnosc wytwarzania biofilmu na powierzchni wybranych biomaterialów.

The ability of yeasts to form biofilm is believed to play an important role in patomechanism of fungal infection. Candida sp. is considered to form biofilm on surfaces of biomaterials used in production of catheters, drains and prosthesis. Therefore this may lead to serious problems in patients with biomaterials used for diagnostic or therapeutic purposes. The aim of the study was to evaluate the influence of cell surface hydrophobicity (CSH) of Candida sp. on biofilm formation on different biomaterials. CSH was evaluated by two methods: Salt Aggregation Test (SAT) and Microbe Adhesion to Hydrocarbon Test (MATH). Biofilm formation on different biomaterials was measured by Richard's method after 72 hour incubation at 37 degrees C. Candida biofilm formation occurred more frequently in case of strains exhibiting hydrophobic than hydrophilic properties of cell surface. The statistically significant correlation between CSH and ability of biofilm formation on different biomaterials was observed (p < 0.05).

[The evaluation of relationship between the origin of Candida sp. and the ability of biofilm formation on surface of different biomaterials]. / Ocena zaleznosci miedzy pochodzeniem szczepów Candida sp., a ich zdolnoscia wytwarzania biofilmu na powierzchni róznych biomaterialów.

The increase of fungal infections in recent years is connected with the progress in medicine. The vast usage of biomaterials is an inseparable element of contemporary medicine but it also leads to development of infections. The ability to produce biofilm by those yeasts plays an important role in the pathogenesis of candidiasis. Candida biofilm can form on the surface of plastic materials (silicon, polychloride vinyl, polymethacrylate methyl) used to catheters, drains and dentures production that is why it is a serious problem in case of fungal infections in patients who during the diagnosis and treatment have contact with biomaterials. The aim of the study was the assessment of ability to form biofilm on the surface of different biomaterials (latex silicon, polychloride vinyl, polystyrene, nylon and polymethacrylate methyl). 150 strains of Candida sp. were examined: 85 (56.7%) C. albicans and 65 (43.3%) C. non-albicans. The examined yeasts produced biofilm on the surface of polymethacrylate methyl in 39.3%, latex silicone in 38.7%, polychloride vinyl in 38.0%, polystyrene in 35.3% and nylon in 30.7%. Biofilm was most frequently produced by the strains of C. albicans, C. tropicalis, C. glabrata, C. parapsilosis, C. krusei and C. lusitaniae species.

[Hydrophobic properties of Candida sp. comparing the two methods]. / Wlasciwosci hydrofobowe Candida sp.--analiza porównawcza dwóch metod.

Yeast-like fungi Candida albicans are still the main pathogen of candidiasis although in recent years the growth of infections caused by Candida non-albicans species such as C. glabrata, C. parapsilosis, C. tropicalis have been observed. The aim of the study was the assessment ofhydrophobic properties of Candida sp. on the basis of methods: salt aggregation test (SAT) and to p-xylene (MATH). 150 strains of Candida sp. were examined: 85 (56.7%) C. albicans and 65 (43.3%) C. non-albicans among which there were 14 (9.3%) strains of C. tropicalis, 13 (8.7%) of C. glabrata, 12 (8.0%) of C. parapsilosis, 8 (5.3%) strains of C. krusei and C. lusitaniae, 6 (4.0%) strains of C. famata, 2 strains of C. glabrata and 1 strains of C. kefyr and C. lipolytica. The assessment of hydrophobic properties was done in MATH method the higher percentage (38.7-53.3%) of the strains with hydrophobic properties was found in comparison with the method SAT--23.3-37.3%. Hydrophobic properties were more often observed in case of C. non-albicans strains than C. albicans depending on growth temperature.