Chromogenic Medium Research Articles

Three-Dose Antifungal Treatment Improves the Efficacy for Severe Vulvovaginal Candidiasis

Vulvovaginal candidiasis (VVC) is a prevalent gynecological infection characterized by high incidence and recurrent episodes, causing significant distress in women. This study aims to assess the effectiveness of different clotrimazole and fluconazole treatment regimens for severe vulvovaginal candidiasis (SVVC). A retrospective analysis was conducted on 1303 cases of SVVC among first-time visitors to the gynecology outpatient department at Peking University Shenzhen Hospital between January 2013 and December 2022. Vaginal secretions were systematically collected for fungal culture, with species identification conducted using Chromogenic culture medium and API Candida test reagents. Mycological cure rates were assessed at days 7–14, days 25–35, and day 35 to 6 months after treatment. The three-dose clotrimazole regimen demonstrated significantly higher mycological cure rates (85.7%, 80.0% and 74.6% at three follow-up periods, respectively) compared to the two-dose clotrimazole regimen (76.0%, 61.6%, and 59.8%, all P < 0.05). The three-dose fluconazole regimen showed no significant difference to three-dose clotrimazole regimen, with cure rates of 82.8%, 79.3%, and 75.9% (all P > 0.05). The two-dose fluconazole regimen had cure rates of 74.3%, 56.4% and 51.1%, with no significant difference from two-dose clotrimazole regimen at days 7–14 and 25–35, but lower than three-dose fluconazole regimen at days 25–35 and 35 to 6 months. The three-dose clotrimazole regimen demonstrated higher cure rates in Candida albicans and non-albicans Candida SVVC cases than two-dose regimen. These findings suggest that three-dose antifungal regimens may be more efficacious than two-dose regimens for SVVC. The three-dose clotrimazole regimen could serve as a promising alternative for SVVC management.

Carbapenem-resistant Klebsiella oxytoca transmission linked to preoperative shaving in emergency neurosurgery, tracked by rapid detection via chromogenic medium and whole genome sequencing

Carbapenem-resistant Klebsiella oxytoca transmission linked to preoperative shaving in emergency neurosurgery, tracked by rapid detection via chromogenic medium and whole genome sequencing

Distribution of TEM and SHV Genes in ESBL-Producing Klebsiella pneumoniae Strains Isolated From Various Clinical Samples in Al-Basrah Province, Iraq

Klebsiella pneumonia is an opportunistic pathogen causes several diseases including sepsis, pneumonia, and wound infections. Antimicrobial resistance (AMR) in MDR K.pneumonia carrying genes for extended-spectrum β-lactams (ESBLs) has been considered a risk for health problems around the world, which has greatly limited treatment options. The current study relied on n=26 Klebsiella pneumoniae isolates that were previously isolated by the studies of master’s student “Intithar Mahdi Mozan" between October 2022 and December 2022,the samples were collected from three hospitals in Al-Basrah province,Iraq. K. pneumoniae isolates reactivated and re-identified by cultivating isolates on MacConkey agar and Klebsiella pneumoniae chromogenic media and then re-identified K. pneumoniae isolates through diagnostic gene 16S rDNA by PCR technique, the results revealed that all n= 26 isolates of K. pneumoniae had a molecular weight of approximately 130 bp at a 100%. Double disk approximation test (DAM) was used to detected produced extended-spectrum β-lactams (ESBLs), the result of current study was showed positive results for the ESBLs. Extended-spectrum β-lactamses (ESBLs) genes was detected by using three specific primers: blaTEM, blaSHV and, blaCTX-M. Out of n=26 K. pneumoniae isolates results was shown the 23 (88.46%) K. pneumoniae isolates had gave positive results for the blaTEM gene. While 3 (11.538%) K. pneumoniae isolates revealed negative results for blaTEM gene. On other hand results were shown that only 5 (19.23%) K. pneumoniae isolates had positive results for blaSHV gene and 21 (80.769%) K. pneumoniae isolates had negative results for the blaSHV gene. Also the results shown the 5(19.23%)K. pneumoniae isolates had positive results for blaTEM and blaSHV genes.

Improving Fungal Product Yield through Fast, Eco-friendly, and Cost-effective Chrom Genic Media Technology

The cost of commonly available culture media is a source of concern for many researchers, highlighting the need to explore more cost-effective alternatives or reduce the use of additives. Despite limited research in this area, efforts have been made to identify alternative culture media that are economically viable for cultivating microorganisms. This study explored the potential of beetroot extract as a cost-effective medium with col-or-inducing properties for fungal growth and as a chromogenic medium for testing lipase enzyme production efficiently as one of the rapid differential tests. The results indicated that Beetroot Agar Medium (BAM) offered significant cost savings in fungal cultivation while facilitating rapid fungal growth compared to other expensive and time-consuming media. Within a 3-4 day incubation period at a temperature range of 25-27 ˚C, all isolated fungi exhibited robust growth. Furthermore, the medium successfully served as a chromogenic differentiating medium by inducing fungi to produce lipase. These findings have broad implications for bio-technology and industrial applications, providing a sustainable and efficient alternative for microbial cultivation.

Performance of common primary and chromogenic culture media for MALDI-TOF MS identification of clinically relevant yeasts.

Timely and accurate identification of yeasts is essential for adequate treatment, considering the increase in antifungal resistance of some species, particularly for C. auris. Current matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) manufacturer's protocol for identification of yeasts requires 24- to 72-h cultivation on Sabouraud dextrose media (SAB), but not some of the mainstay primary culture media used in mycology such as inhibitory mold agar (IMA), Mycosel, CHROMagar Candida Plus, and CHROMagar Candida. As culture media can influence MALDI-TOF MS identification results, this study evaluated the accuracy and performance of identification of clinically relevant yeasts on these first-line media using the VITEK-MS MALDI-TOF MS system.IMPORTANCEIn this study, a panel of 140 strains (21 species) was used to assess the performance of the selected media. Although not in the manufacturer's list of accepted media, IMA and chromogenic media are suitable for the identification of yeasts on the VITEK-MS systems. CHROMagar Candida Plus allowed the identification of 135/140 isolates tested after 24-h incubation similar to SAB reference media (137/140). Yeast isolates that grew on Mycosel selective media were also reliably identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. VITEK-MS system with IVD database V3.2 correctly identified C. auris strains to the species level on CHROMagar Candida Plus alleviating the need for subcultivation and reduced turnaround time (24-72 h) to identification for patient screening.

Phenotypic and Genotypic Characterization of Resistance and Virulence Markers in Candida spp. Isolated from Community-Acquired Infections in Bucharest, and the Impact of AgNPs on the Highly Resistant Isolates.

This study aimed to determine, at the phenotypic and molecular levels, resistance and virulence markers in Candida spp. isolated from community-acquired infections in Bucharest outpatients during 2021, and to demonstrate the efficiency of alternative solutions against them based on silver nanoparticles (AgNPs). A total of 62 Candida spp. strains were isolated from dermatomycoses and identified using chromogenic culture media and MALDI-TOF MS, and then investigated for their antimicrobial resistance and virulence markers (VMs), as well as for metabolic enzymes using enzymatic tests for the expression of soluble virulence factors, their biofilm formation and adherence capacity on HeLa cells, and PCR assays for the detection of virulence markers and the antimicrobial activity of alternative solutions based on AgNPs. Of the total of 62 strains, 45.16% were Candida parapsilosis; 29.03% Candida albicans; 9.67% Candida guilliermondii; 3.22% Candida lusitaniae, Candia pararugosa, and Candida tropicalis; and 1.66% Candida kefyr, Candida famata, Candida haemulonii, and Candida metapsilosis. Aesculin hydrolysis, caseinase, and amylase production were detected in the analyzed strains. The strains exhibited different indices of adherence to HeLa cells and were positive in decreasing frequency order for the LIP1, HWP1, and ALS1,3 genes (C. tropicalis/C. albicans). An inhibitory effect on microbial growth, adherence capacity, and on the production of virulence factors was obtained using AgNPs. The obtained results in C. albicans and Candida non-albicans circulating in Bucharest outpatients were characterized by moderate-to-high potential to produce VMs, necessitating epidemiological surveillance measures to minimize the chances of severe invasive infections.

Degree of Contamination of Gutta-Percha Points by Staphylococcus aureus (MRSA/MSSA) Strains.

We performed an in vitro analysis of the contamination of GP points, regarding the strains of Methicillin-resistant (MRSA) and Methicillin-sensitive (MSSA) Staphylococcus aureus, using classical microbiology methods and molecular biology techniques. Gutta-Percha points of two different brands from opened packages (already in use for 1 month) were collected for analysis. The assessment involved incubating the GP points in Brain Heart Infusion (BHI) medium to detect microbial growth. Growing microorganisms were plated on a selective and differential chromogenic medium for MRSA/MSSA strains, and the identification of isolates was confirmed by Polymerase Chain Reaction (PCR). In the case of microbial growth, the GP point was submitted to a disinfection protocol. From the 315 collected GP points, only 6 (1.9%) resulted in being positive for microbial growth. After confirmation by PCR, only one sample of the six GP points was contaminated by MRSA, and the remaining five were MSSA-contaminated. The disinfection protocol was effective in all contaminated GP points. The Gutta-Percha points from opened pre-sterilized packages showed a very low degree of contamination by MRSA/MSSA. However, the detection of MSSA and MRSA strains raises concerns about potential contamination in dental clinic environments, and this risk cannot be considered negligible.

Comparative Analysis of the Mass Spectra of Mycobacterium abscessus Complex Strains Isolated on Various Nutrient Media.

Mycobacterium abscessus complex (MABSc) causes chronic infection in patients with concomitant structural changes in the respiratory tract, which is especially important for patients with cystic fibrosis. To isolate an MABSc culture from clinical material, a variety of nutrient media are used. For species determination of microorganisms isolated on these media, additional identification methods are used, for example, polymerase chain reaction, sequencing, or mass spectrometry. The latter method is relatively easy to implement but requires improvement, due to the identification inaccuracy of nontuberculosis mycobacterias in general. Consequently, a set of nutrient media may be important for subsequent identification by mass spectrometry. The study was conducted on 64 strains of MABSc representatives: 56 strains were obtained from patients with cystic fibrosis and 8 strains from patients with pulmonary pathology unrelated to cystic fibrosis. The obtained MABSc strains were transplanted to the universal chromogenic medium and the selective medium for the Burkholderia cepacia complex (BCC) isolation. Species identification was carried out by mass spectrometry based on matrix-activated laser time-of-flight desorption/ionization (MALDI-ToF MS). Microbial identification is based on a comparison of the obtained mass spectra with reference spectra from the database. Microorganisms were identified based on the coincidence degree (Score value). Sample preparation for microbial identification by mass spectrometry was carried out by an extended direct application method. Fragments of the rpoB and hsp65 genes with lengths of 752 bp and 441 bp, respectively, were used as molecular markers for subspecific identification of MABSc strains. A comparison of the peaks obtained after mass spectrometry of MABSc strains isolated on the studied nutrient media showed significant differences between these indicators selective medium for the BCC isolation with the supplement of iron polymaltose hydroxide (III) and universal chromogenic medium (P < 0.001) and selective medium for the BCC isolation with universal chromogenic medium (P < 0.001). Twenty-five strains of MABSc representatives were sequenced: results of subspecies determination in strains isolated on the universal chromogenic medium coincided with the results sequencing in 13 (86.6%) strains out of 15. MALDI-ToF mass spectrometry allows microbial identification in a short time and with minimal cost, but it does not yet allow the proper identification of the subspecies of certain microbial groups, such as MABSc. Cultivation methods need optimization and new approaches to the extraction process of the bacterial protein fraction.

Temporal decreases in pathogen colonization and infection among hospitalized neonates following routine skin antisepsis with chlorhexidine gluconate: Botswana 2022 – 2023

Background: Multidrug-resistant Gram-negative bacteria are a major cause of sepsis among hospitalized neonates globally. Aqueous chlorhexidine gluconate (CHG) skin antisepsis has been shown to be safe for use in infants; however, its sustained effectiveness in preventing Gram-negative pathogen colonization, bloodstream infection (BSI), and mortality is unclear. Methods: We conducted a period prevalence survey, with 26 sampling events over 12 months (18 October 2022 – 31 October 2023) at a 33-bed neonatal unit in a tertiary public hospital in Botswana where ESBL-producing Klebsiella pneumoniae and carbapenem-resistant Acinetobacter baumannii are leading causes of BSI. Perirectal and periumbilical skin swabs were collected every two weeks from all inpatients. Swabs were inoculated onto chromogenic media selective and differential for extended-spectrum beta-lactamase producing Enterobacterales (ESBL-E) and Acinetobacter spp. (CHROMagar™ ESBL, Acinetobacter). Colonization status was determined based on culture growth and colony morphology. Contemporaneous data on all-cause mortality and BSI were abstracted from routine surveillance records. Pre- and post-CHG prevalences were compared using a simple Chi-square test. During the surveillance period, an outbreak of K. pneumoniae linked to contaminated multi-use vials was detected, thus BSIs and deaths during the outbreak period (2 February–6 April, 2023) were excluded. In February 2023, the hospital infection prevention and control (IPC) team introduced twice-weekly whole-body cleansing with commercially available 2% aqueous CHG, performed by caregivers and healthcare workers on neonates &gt;24 hours old and weighing ≥1 kg until discharge. Results: There were significant decreases in ESBL-E and Acinetobacter skin and perirectal colonization following the CHG intervention (Table 1; Figure 1). After the CHG intervention, the incidence of Acinetobacter BSIs declined significantly and there was a trend toward a decline in other BSIs and mortality. No adverse events associated with CHG were reported. Conclusions: Twice-weekly CHG application was temporally associated with significant reductions in neonatal ESBL-E and Actinetobacter skin and perirectal colonization and Acinetobacter BSI. This analysis was limited by a short pre-intervention surveillance period and thus may have been influenced by confounders such as seasonality, and intensified IPC efforts following the outbreak. Analysis of the routine CHG use in other settings and over longer surveillance periods are needed to better understand its effectiveness as an IPC strategy in settings where neonatal sepsis incidence is high. Table 1. Colonization prevalence, BSI incidence, and mortality surrounding introduction of CHG skin cleansing in a neonatal unit, 18 October 2022 – 31 October 2023.

Increase in methicillin-resistant Staphylococcus spp. colonization among pregnant individuals during COVID-19 pandemic

Methicillin-resistant Staphylococcus (MRS) has been associated with neonatal infections, with colonization of the anovaginal tract being the main source of vertical transmission. The COVID-19 pandemic has altered the frequency of antibiotic usage, potentially contributing to changes in the dynamics of bacterial agents colonizing humans. Here we determined MRS colonization rates among pregnant individuals attending a single maternity in Rio de Janeiro, Brazil before (January 2019–March 2020) and during (May 2020–March 2021) the COVID-19 pandemic. Anovaginal samples (n = 806 [521 samples before and 285 during the pandemic]) were streaked onto chromogenic media. Colonies were identified by MALDI-TOF MS. Detection of mecA gene and SCCmec typing were assessed by PCR and antimicrobial susceptibility testing was done according to CLSI guidelines. After the onset of the pandemic, MRS colonization rates increased significantly (p < 0.05) from 8.6% (45) to 54.7% (156). Overall, 215 (26.6%) MRS isolates were detected, of which S. haemolyticus was the most prevalent species (MRSH, 84.2%; 181 isolates). SCCmec type V was the most frequent among MRS (63.3%; 136), and 31.6% (68) of MRS strains had a non-typeable SCCmec, due to new combinations of ccr and mecA complexes. Among MRS strains, 41.9% (90) were resistant to at least 3 different classes of antimicrobial agents, and 60% (54) of them were S. haemolyticus harboring SCCmec V. MRS colonization rates and the emergence of multidrug-resistant variants detected in this study indicate the need for continuing surveillance of this important pathogen within maternal and child populations.

Decoding the resistome, virulome and mobilome of clinical versus aquatic Acinetobacter baumannii in southern Romania

Acinetobacter baumannii, a notorious opportunistic pathogen, presents a formidable challenge in both clinical and environmental fields due to its resilience and ability to acquire resistance. This study undertook a comprehensive analysis of 183 A. baumannii isolates collected between 2019 and 2022 from intra-hospital infections (IHI), hospital sewages (Hs), wastewater treatment plants (WWTP), and adjacent river waters from two Southern cities, focusing on their resistome, virulome, and mobilome through isolation on chromogenic media, identification by MALDI-TOF-MS and antibiotic susceptibility testing by disk diffusion) followed by genotypic characterization [Whole Genome Sequencing (WGS), 3rd generation sequencing through the MinION (ONT) platform, pangenome description, and respectively horizontal gene transfer through conjugation assays]. Our findings reveal significant genomic plasticity and the prevalence of high-risk international clones, underlining the potential of these isolates to act as reservoirs for antibiotic resistance genes (ARGs) that could be dynamically exchanged between clinical and environmental settings through mobile genetic elements (MGEs) such as the pMAL1 plasmids and the critical role of WWTPs in the persistence and spread of A. baumannii. Moreover, our study presents the first report of the co-occurrence of blaOXA-23 and blaOXA-72 in A. baumannii ST2 clone. Thus, our research underscores the necessity for integrated surveillance and targeted interventions across healthcare and environmental sectors to mitigate the risk posed by this adaptable pathogen.

Pediatric Urinary Tract Infections at a Tertiary Care Center: Microbial Diversity and Antibiotic Resistance Patterns

Abstract Introduction: Urinary tract infection (UTI) remains a prevalent bacterial infection among the pediatric age group, ranking as the third-most common bacterial infection in children in developing countries, following gastrointestinal and respiratory tract infections. It continues to pose a significant health challenge. Materials and Methods: The urine samples underwent gross examination, wet mount, and Gram stain. Semiquantitative cultures were conducted on conventional media (MacConkey agar, blood agar, and CLED agar) and UTI chromogenic media. Uropathogen identification employed standard microbiological techniques. Antibiotic susceptibility was determined using the Kirby–Bauer disk diffusion method, with interpretation based on CLSI guidelines. Plates were incubated overnight, and clear zone diameters around antibiotic discs were measured for sensitivity or resistance determination. Results: The study comprised 64.75% male children and 35.25% female children. Analyzing the age distribution, the majority of participants fell within the age range of 1–5 years (35%), followed by those &lt;1 year (33.75%), and the age group of 5–12 years, accounting for 31.25% of the total 400 participants. The findings from our investigation revealed a UTI prevalence of 17.25%, with Escherichia coli and Klebsiella emerging as the predominant uropathogens. Notably, these pathogens exhibited a significant susceptibility to carbapenems, nitrofurantoin, and amikacin. Conclusion: Our study identified a male predominance and various age distributions among UTI patients. Antibiotic susceptibility patterns revealed E. coli and Klebsiella pneumoniae’s high sensitivity to key antibiotics, whereas Enterococcus spp. exhibited significant high-level aminoglycoside resistance. This study underscores the importance of tailored antibiotic strategies based on local resistance profiles to combat UTIs effectively.

Detection and Antimicrobial Susceptibility of Candida Species Isolated from the Urine of Patients in a Tertiary Health Facility, Southwest Nigeria

Aims: This study aimed to identify and determine the antimicrobial susceptibility profiles of Candida species causing UTI among patients attending a tertiary Teaching Hospital, in southwest Nigeria. Study Design: Comparative cross-sectional study. Place and Duration of Study: Lagos State University Teaching Hospital, Ikeja, Nigeria between June 2017 and February, 2018. Methodology: A total of 250 participants whose provisional diagnosis was candiduria were recruited for this study. Urine samples were collected from consenting participants early in the morning into sterile wide mouth universal containers. These samples were cultured aerobically on Blood agar, Cystine-Lactose-Electrolyte Deficient (CLED) agar and Sabouraud dextrose agar (SAB) at 370C within 1 to 2 days. The isolates were profiled into species level using microscopic, biochemical test, chromogenic media (Chrom agar Candida) and Analytical Profile Index (API) 32C examination analysis. Results: An overall rate for Candidiasis in this study was 12.8% (32/250). The rate was higher in female 17.5% compared to 6.5% in their male counterparts (p=0.014). Highest rate of infections peaked at 28.6% among age group 83-92 years and lowest (6.7%) in age group 23-32 years. A total of 11 (4.4%) urine culture from participants produced C. albicans pure fungi isolates. However, by gender, this was statistically significant (p=0.003). A total of 81 bacterial (32.4%) and fungal isolates 32 (12.8%) were isolated and profiled. Distribution of Candida species indicated highest incidence in age range 31-40 years, followed by 21-30years and age 61-70 years age brackets. The isolated species were Candida albicans 11(34.4%), C. tropicalis 8(25%), C. parapsilopsis 6(19%), C. krusei 2(6.3%) and C. hellenica 1(3.1%). Sixty to seventy percent of fungal isolates were susceptible to ketoconazole and fluconazole while the susceptibility pattern of Candida species to itraconazole, terbinafine and nystatin varied between moderately susceptible to resistance. All the Candida isolates were resistant to griseofulvin. However, C. albicans was found to be the major Candida species causing Candidal urinary tract infection. The only C. hellenica isolated was resistant to all the antifungal drugs were approved except nystatin. Conclusion: High profile of Candida isolates and related UTI microbes were found in this study. There is need for advocacy for the use of API and Chrom agar Candida for routine diagnosis for Candida identification. Nevertheless, the Candida isolates were mostly susceptible to ketoconazole and Fluconazole but only the isolates were griseofulvin resistant.

Prevalence and Risk Factors for Colonization by Multidrug-Resistant Microorganisms among Long-Term Travelers and Recently Arrived Migrants.

Multidrug-resistant (MDR) bacteria have become one of the most important health problems. We aimed to assess whether international travel may facilitate their spread through the colonization of asymptomatic travelers. A cross-sectional study was conducted (November 2018 to February 2022). Pharyngeal and rectal swabs were obtained from long-term travelers and recently arrived migrants from non-European countries, and an epidemiological survey was performed. Colonization by Gram-negative bacteria and methicillin-resistant Staphylococcus aureus (MRSA) was determined by chromogenic media and MALDI-TOF-MS. Resistance mechanisms were determined by the biochip-based molecular biology technique. Risk factors for colonization were assessed by logistic regression. In total, 122 participants were included: 59 (48.4%) recently arrived migrants and 63 (51.6%) long-term travelers. After their trip, 14 (11.5%) participants-5 (8.5%) migrants and 9 (14.3%) travelers-had rectal colonization by one MDR bacterium. Escherichia coli carrying the extended-spectrum beta-lactamase (ESBL) CTX-M-15 was the most frequent. No participants were colonized by MRSA or carbapenemase-producing Enterobacteriaceae. The only risk factor independently associated with MDR bacterial colonization was previous hospital attention [OR, 95% CI: 10.16 (2.06-50.06)]. The risk of colonization by MDR bacteria among recently arrived migrants and long-term travelers is similar in both groups and independently associated with previous hospital attention.

Biosafety of gado-gado street food around Jember campus

The gado-gado food is the Javanese salad with peanut sauce consists of vegetable filling, lontong, potatoes, eggs, tofu and peanut sauce so has complete nutritional content, namely carbohydrates, fiber, protein and a little fat. This research aims to determine the biosafety of gado-gado food from street vendors around the Jember campus. This research is an exploratory study that investigates the biosafety of gado-gado street food around the Jember campus based on exposure to enteric microbes as an sanitation indicator using the chromogenic media. The isolated microbes were determined the fermentation profile using the BBL Crystal kit. Sampling was taken in three different places in zone 1 (A1), zone 2 (A2) and zone 3 (A3). The sampling time was carried out at 10am when the trader had just opened his stall (B1) and at 3pm before the trader closed his stall (B2). The amount of total bacterial in gado-gado from the street vendors around the Jember campus reached up to 105 CFU/g. The blue colony was identified as Raoutella planticola, which mostly comes from the soil and water. It is recommended that protect the street food from dust, air and need good handling of food service.

Kodamaea ohmeri: A rare yeast causing invasive infections in immunocompromised patients.

Kodamaea ohmeri is a rare, recognized pathogen that has previously been isolated from environmental sources. The patients commonly affected by this yeast include immunocompromised as well as immunocompetent patients having several associated risk factors. We report three cases in which K. ohmeri was isolated from blood using Bact T/ALERT. Identification was carried out by MALDI-TOF MS (Vitek-MS, BioMérieux, Marcy-l'Etoile, France) in addition to color characteristics on chromogenic media. The patients had diminished immune response on account of a multitude of comorbidities. K. ohmeri can be misidentified as Candida tropicalis, Candida albicans, or Candida hemolounii by conventional methods; correct and timely identification can be achieved by MALDI-TOF MS. Antifungal susceptibility breakpoints for K. ohmeri are currently not defined. An Echinocandin was added to the treatment regimen of all three of the cases. Identification of K. ohmeri using conventional methods is difficult and unusual yeasts should be carefully observed, especially upon prolonged incubation.

Characteristics of antibiotic sensitivity of Acinetobacter baumannii bv. tryptophandestruens and Acinetobacter baumannii clinical isolates

The aim of the study was to determine the sensitivity of the bacteria of the biovar Acinetobacter baumannii bv. tryptophandestruens to antibiotics used to treat Acinetobacter-infection. The object of the study was 86 primary clinical isolates of A. baumannii, of which 34 strains of A. baumannii bv. tryptophandestruens isolated in the microbiological laboratory of the Military Medical Academy in 2021–2022. Species identification of bacteria was carried out by MALDI-ToF mass spectrometry. The biovar tryptophandestruens of A. baumannii was determined on a dense chromogenic medium. The sensitivity of A. baumannii isolates to antibiotics was determined by a “Vitek 2 compact” microbiological analyzer (bioMerieux, France). Clinical categories of isolates sensitivity to antibiotics (S) were identified based on the boundary values of minimum suppressive concentrations (MSC, mg/L) established by the European Committee for the Determination of Sensitivity to Antimicrobial Preparates (EUCAST), version 11.0. Isolates of A. baumannii bv. tryptophandestruens and groups of isolates of other A. baumannii very rarely sensitive to meropenem (8.8±4.6%; 3.8±2.6%, respectively, p 0.05), ciprofloxacin (5.8±4.0; 9.6±4.1%, p 0.05). Strains sensitive to gentamicin are rarely represented in both groups (26.7±7.55; 19.3±5.5%, p 0.05) trimethoprim/sulfamethoxazole (38.8±8.3%; 23.6±5.3%, p 0.05). Sensitivity to polymyxin B was preserved in all strains of both groups (100%). Strains of the tryptophandestruens biovar A. baumannii group surpass strains of the other strain of A. baumannii group in the frequency of isolates with MSC50% tigecycline (MSC50% — 0.5 mg/l; MSC50% — 2 mg/l, respectively), and also have significantly more strains with MSC 0.5 mg/l (52.9% and 15.4%, respectively, p 0.01 ). Thus, the clinical isolates of the biovar A. baumannii bv. tryptophandestruens have no significant differences with isolates of other strains of A. baumannii in the frequency of strains sensitive (S) to meropenem, ciprofloxacin, gentamicin, trimethoprim/sulfamethoxazole, polymyxin B, but they differ in terms of sensitivity to tigecycline — a higher frequency of strains with an MSC of 0.5 mg/l (p 0.01) and an MSC of 50%.

Comparison of Candida colonization in intensive care unit patients with and without COVID-19: First prospective cohort study from Turkey.

Candida species are the primary cause of fungal infections in intensive care units (ICUs). Despite the increasing prevalence of Candida-related infections, monitoring the progression of these infections from colonization in COVID-19 ICU patients lacks sufficient information. This study aims prospectively to compare 62 COVID-19 and 60 non-COVID-19 ICU patients from admission to discharge in terms of colonization development, rates, isolated Candida species, risk factors, and Candida infections during hospitalization. A total of 1464 samples were collected at specific time intervals from various body sites [mouth, skin (axilla), rectal, and urine]. All samples were inoculated onto CHROMagar Candida and CHROMagar Candida Plus media, and isolates identified using MALDI-TOF MS. COVID-19 patients exhibited significantly higher colonization rates in oral, rectal, and urine samples compared to non-COVID-19 patients, (p<0.05). Among the Candida species, non-albicans Candida was more frequently detected in COVID-19 patients, particularly in oral (75.8%-25%; p<0.001) and rectal regions (74.19% - 46.66%; p<0.05). Colonization with mixed Candida species was also more prevalent in the oropharyngeal region (p<0.05). Mechanical ventilation and corticosteroid use emerged as elevated risk factors among COVID-19 patients (p<0.05). Despite the colonization prevalence, both COVID-19-positive and negative patients exhibited low incidences of Candida infections, with rates of 9.67% (n=6/62) and 6.67% (n=3/60), respectively. Consequently, although Candida colonization rates were higher in COVID-19 ICU patients, there was no significant difference in Candida infection development compared to the non-COVID-19 group. However, the elevated rate of non-albicans Candida isolates highlights potential future infections, particularly given their intrinsic resistance in prophylactic or empirical treatments if needed. Additionally, the high rate of mixed colonization emphasizes the importance of using chromogenic media for routine evaluation.

Emerging Issues on Antibiotic-Resistant Bacteria Colonizing Plastic Waste in Aquatic Ecosystems.

Antibiotic-resistant bacteria (ARB) adhesion onto plastic substrates is a potential threat to environmental and human health. This current research investigates the prevalence of two relevant human pathogens, Staphylococcus spp. and Klebsiella spp., and their sophisticated equipment of antibiotic-resistant genes (ARGs), retrieved from plastic substrates submerged into an inland water body. The results of microbiological analysis on selective and chromogenic media revealed the presence of colonies with distinctive phenotypes, which were identified using biochemical and molecular methods. 16S rDNA sequencing and BLAST analysis confirmed the presence of Klebsiella spp., while in the case of Staphylococcus spp., 63.6% of strains were found to be members of Lysinibacillus spp., and the remaining 36.3% were identified as Exiguobacterium acetylicum. The Kirby-Bauer disc diffusion assay was performed to test the susceptibility of the isolates to nine commercially available antibiotics, while the genotypic resistant profile was determined for two genes of class 1 integrons and eighteen ARGs belonging to different classes of antibiotics. All isolated bacteria displayed a high prevalence of resistance against all tested antibiotics. These findings provide insights into the emerging risks linked to colonization by potential human opportunistic pathogens on plastic waste commonly found in aquatic ecosystems.

Research Note: Validation of a new differentiation approach using the commercial ASAPTM media to detect the Salmonella 441/014 vaccine strain

Vaccination is one of the most important control tools to reduce Salmonella in poultry production. In order for a live vaccine to be licensed for field use it should be provided with the detection methods to differentiate it from field strains. This paper aims to describe the validation of an alternative method for the differentiation of the Salmonella 441/014 vaccine strain from field strains, using a chromogenic Media, ASAP from bioMérieux. The ASAP-based differentiation method was compared with already authorized methods, namely the Anicon SE Kylt PCR DIVA 1 assay and Ceva S-Check Salmonella differentiation kit, following the ISO 16140-6:2019 validation method guidelines. A Generalised Linear Model was fitted to the data to determine the inclusivity and exclusivity of differentiation methods (PCR Kylt vs. S-Check vs. ASAPTM). Statistical differences were based on a P-value level of < 0.05 (SPSS Inc., Chicago, IL). In this study, we show that the ASAP media was able to differentiate Salmonella Enteritidis vaccine strains from field strains, obtaining 100% agreement between the three differentiation assays. This differentiation approach is quicker, easier to deploy and cheaper as compared to alternative methods.