Susceptibility Profiles Research Articles

Antibiotic Susceptibility Profile of Bacteria Responsible for Urogenital Infections and Epidemiology in Women at the Ignace Deen National Hospital in Conakry (Republic of Guinea)

Antibiotic Susceptibility Profile of Bacteria Responsible for Urogenital Infections and Epidemiology in Women at the Ignace Deen National Hospital in Conakry (Republic of Guinea)

The Microbial Diversity and Antimicrobial Susceptibility Profile Underlying Diabetic Foot Osteomyelitis: A Retrospective Study Conducted in North Queensland, Australia.

Diabetic foot osteomyelitis (DFO) commonly occurs secondary to ulcerations of the skin. Empirical antibiotic agents are a key element of treatment and their use is dependent on local knowledge of the microbial spectrum of diabetic foot infections. This study aimed to retrospectively analyze the local microbiological profile, including bacterial culture/sensitivity results of DFO, and compare findings with literature. This study also aimed to review the concordance of microbiology results with national guidelines for the future treatment of DFO. A retrospective review of clinical records was performed on patients who presented to the high-risk foot clinic, Townsville University Hospital, between 2018 and 2022. All patients older than 18 years and diagnosed with DFO were included. Our exclusion criteria included all other foot presentations, including trauma, vasculitis, and neoplasms. On the basis of the inclusion and exclusion criteria, 124 patients with DFO were selected. Most patients in the cohort were males (70.2%), non-Indigenous (68.5%), aged 50-69 years (55.6%), and with elevated HbA1c levels (>8.6). Chronic kidney disease (39.5%) and ischemic heart disease (41.9%) were common comorbidities. Of the pertinent microbial results, Staphylococcus aureus (~76%) was the most commonly isolated Gram-positive organism. Gram-positive bacteria were significantly increased in the elderly population with DFO (P < .05). All methicillin-resistant S aureus isolates were vancomycin- and cotrimoxazole-sensitive. Pseudomonas aeruginosa was the predominant Gram-negative organism isolated (39.3%). P aeruginosa exhibited low sensitivity to ciprofloxacin. This study has enhanced our understanding of the various microbial species underlying DFO at our center and may be generalizable. Level IV, retrospective case series.

Retrospective study on the occurrence of Salmonella serotypes in veterinary specimens of Atlantic Canada (2012-2021).

This study aimed to summarize the frequency and the antimicrobial susceptibility profiles of the Salmonella serotypes identified from the specimens of companion animals, livestock, avian, wildlife and exotic species within Atlantic Canada. The retrospective electronic laboratory data of microbiological analyses of a selected subset of samples from 03 January 2012 to 29 December 2021 submitted from various animal species were retrieved. The frequency of Salmonella serotypes identified, and their antimicrobial susceptibility results obtained using the disk diffusion or broth method were analysed. The test results were interpreted according to the Clinical and Laboratory Standards Institute standard. The Salmonella serotypes were identified by slide agglutination (Kauffman-White-Le-Minor Scheme) and/or the Whole Genome Sequencing for the Salmonella in silico Serovar Typing Resource-based identification. Of the cases included in this study, 4.6% (n=154) had at least one Salmonella isolate, corresponding to 55 different serovars. Salmonella isolation was highest from exotic animal species (n=40, 1.20%), followed by porcine (n=26, 0.78%), and canine (n=23, 0.69%). Salmonella subsp. enterica serovar Typhimurium was predominant among exotic mammals, porcine and caprine samples, whereas S. Enteritidis was mostly identified in bovine and canine samples. S. Typhimurium of porcine origin was frequently resistant (>70.0%) to ampicillin. In contrast, S. Typhimurium isolates from porcine and caprine samples were susceptible (>70.0%) to florfenicol. S. Oranienburg from equine samples was susceptible to chloramphenicol, but frequently resistant (>90.0%) to azithromycin. In avian samples, S. Copenhagen was susceptible (>90.0%) to florfenicol, whereas Muenchen was frequently resistant (>90.0%) to florfenicol. S. subsp. diarizonae serovar IIIb:61:k:1,5 of ovine origin was resistant (50.0% isolates) to sulfadimethoxine. No significant changes were observed in the antibiotic resistance profiles across the study years. This report provides data for surveillance studies, distribution of Salmonella serotypes and their antimicrobial resistance among veterinary specimens of Atlantic Canada.

Phenotypic Characterization of Methicillin-Resistant Staphylococci Isolated from Wounds and Nasal Swabs in Selected Hospitals Across some Northwestern States, Nigeria

Study’s Novelty/Excerpt This study provides a comprehensive analysis of Methicillin-resistant Staphylococci (MRS) from wounds and nasal swabs in Northwestern Nigeria, focusing on the phenotypic characteristics, antibiotic susceptibility, and socio-demographic profiles of the isolates. The novelty lies in its extensive sampling across nine facilities in four states and its detailed examination of the correlation between educational and economic status and MRS occurrence, which has not been previously reported. These findings offer critical insights for healthcare policy-making in antibiotic usage and infection control in a region-specific context, highlighting socio-demographic factors influencing MRS prevalence. Full Abstract Methicillin-resistant Staphylococci (MRS) remain important opportunistic pathogens most frequently identified worldwide. The study aimed to determine the phenotypic characteristics of Methicillin-resistant Staphylococci, their antibiotic susceptibility patterns, and the socio-demographic characteristics of the isolates from wounds and nasal swabs in selected hospitals across some states in Northwestern Nigeria. A total of 806 wounds and nasal swabs were collected from patients admitted at nine facilities in 4 states of Northwestern Nigeria. All samples underwent analysis using standard bacteriological techniques. Antibiotic susceptibility testing (AST) was conducted using the Kirby-Bauer technique. Out of 806 samples, 652 (80.3%) were culture positive, while 154 (19.1%) were culture negative. A total of 704 (87.3%) isolates were obtained, out of which 418 (59.4%) were identified as Staphylococci isolates, comprising 144 (17.7%) Methicillin-resistant Staphylococcus aureus (MRSA), 124 (15.4%) Methicillin-susceptible Staphylococcus aureus (MSSA), 89 (11%) Methicillin-resistant coagulase-negative Staphylococci (MRCoNS), and 61 (7.6%) Methicillin susceptible coagulase-negative Staphylococci (MSCoNS). The Staphylococci isolates showed the highest susceptibility to Vancomycin 408 (97.6%), while the lowest was penicillin 24 (5.7%). The isolation rate of MRS was highest among patients aged 11-30, while the 71-90 age group had the lowest rate. The occurrence was higher (37%) in male patients than in female patients (18.6%). Moreover, there was no statistically significant association found between the distribution of MRS among different age groups, gender, and occupational affiliations, but it exists in the educational levels, and economic statuses of the research participants. The occurrence of MRS was lower among patients with a high level of formal education but higher among those without or with a low level of education. These findings will aid healthcare workers in establishing policies for antibiotic usage, surveillance, and infection prevention and control measures.

Bacterial Communities of the Musca Domestica Housefly in Different Urban Habitats and their Antimicrobial Susceptibility Profiles

Bacterial Communities of the Musca Domestica Housefly in Different Urban Habitats and their Antimicrobial Susceptibility Profiles

Prevalence, Diversity, and Antimicrobial Susceptibility Profiles of Methicillin-Resistant Staphylococcus aureus Among Patients with Diabetic Foot Infections in a Referral Hospital in Tehran, Iran

Background: The increasing incidence of methicillin-resistant Staphylococcus aureus (MRSA) poses a significant challenge in the treatment of diabetic foot infections (DFIs). Objectives: This study aimed to investigate the prevalence and diversity of clonal groups of MRSA strains isolated from patients with DFIs in a major referral hospital in Tehran. Methods: We determined the prevalence, diversity, and antibiotic susceptibility profiles of MRSA isolated from patients with DFIs attending a referral hospital in Tehran, Iran, during 2019 - 2020. Staphylococcal cassette chromosome mec (SCCmec) typing, ccr typing, PhP typing, and detection of the Panton-Valentine Leukocidin (pvl) gene were performed to explore the diversity of the strains. Antibiotic susceptibility profiles of the strains were determined using the disk diffusion method and broth microdilution assay. Results: Of the 238 S. aureus strains isolated, 73 were identified as MRSA. The highest antibiotic resistance was observed against ciprofloxacin (86%), followed by kanamycin and tobramycin (84%). Additionally, 49.3% of the strains exhibited high-level oxacillin resistance (MIC ≥ 256 µg/mL). SCCmec type III and type 3 ccr were detected in 86.3% of the strains, classifying them as hospital-acquired (HA)-MRSA. PhP typing revealed the presence of 8 common types (CTs) and 11 single types (STs), with CT2 comprising 41.1% of the strains. Conclusions: Our data suggest that MRSA strains isolated from DFIs in this region are diverse and resistant to clinically important antibiotics. Diabetic patients can serve as a reservoir for the dissemination of these bacteria between community and clinical environments.

The Effect of pH Variation on Antibiotic Susceptibility of MDR &lt;i&gt;Klebsiella pneumoniae&lt;/i&gt; Isolates

Background: Klebsiella pneumoniae is a significant opportunistic pathogen responsible for various nosocomial infections in humans. The emergence of multi-drug resistant strains poses a significant challenge in clinical settings, necessitating a deeper understanding of factors influencing antimicrobial resistance. Objective: This research aimed to investigate the impact of pH variation on the resistance patterns of multi-resistant K. pneumoniae isolated from Iraqi patients with urinary tract infections and wound infections against different antibiotics. Methods: Forty K. pneumoniae isolates were obtained from urine samples and wound swabs, and their identification was confirmed using the VITEK ® 2 compact system and molecular identification of the rpoB housekeeping gene. Antibiotic susceptibility testing was performed using the Kirby Bauer’s disk diffusion method under varying pH conditions (pH 5, 7, 9, and 11) at 37°C for 18 to 24 hours. Results: The study findings indicated that K. pneumoniae isolates exhibited differential susceptibility to antibiotics based on pH conditions. Cefotaxime demonstrated increased efficacy under alkaline pH, while tetracycline showed optimal efficacy under acidic conditions. However, ciprofloxacin displayed resistant phenotypes at acidic pH 5 and either resistant or intermediate phenotypes at alkaline pH 9. Conclusions: The results suggest a potential influence of pH on the antibiotic susceptibility profiles of K. pneumoniae isolates. Understanding the role of pH in antimicrobial resistance can inform strategies for better managing infections caused by multi-resistant pathogens. Further research is warranted to elucidate the underlying mechanisms and implications for clinical practice.

Characterization of Vibrio parahaemolyticus isolated from clinical specimens and oysters in Thailand.

Vibrio parahaemolyticus is a common pathogen that can cause seafood-borne gastroenteritis in humans. We determined the prevalence and characteristics of V. parahaemolyticus isolated from clinical specimens and oysters in Thailand. Isolates of V. parahaemolyticus from clinical specimens (n = 77) and oysters (n = 224) were identified by biochemical testing, polymerase chain reaction (PCR) assays, and serotyping. The toxin genes, antimicrobial resistance, and β-lactamase production were determined. A total of 301 isolates were confirmed as V. parahaemolyticus by PCR using specific primers for the toxR gene. The majority of clinical isolates carried the tdh+/trh- genotype (82.1%), and one of each isolate was tdh-/trh+ and tdh+/trh+ genotypes. One isolate from oyster contained the tdh gene and another had the trh gene. Twenty-six serotypes were characterized among these isolates, and O3:K6 was the most common (37.7%), followed by OUT:KUT, and O4:K9. In 2010, most clinical and oyster isolates were susceptible to antibiotics, with the exception of ampicillin. In 2012, clinical isolates were not susceptible to cephalothin (52.4%), streptomycin (95.2%), amikacin (66.6%), kanamycin (61.9%), and erythromycin (95.2%), significantly more frequently than in 2010. More than 95% of isolates that were not susceptible to ampicillin produced β-lactamase enzymes. We found toxin genes in two oyster isolates, and the clinical isolates that were initially determined to be resistant to several antibiotics. Toxin genes and antimicrobial susceptibility profiles of V. parahaemolyticus from seafood and environment should be continually monitored to determine the spread of toxin and antimicrobial resistance genes.

Isolation and Characterization of Antibiotics-resistant Enteric Bacteria from Borehole Waters in PRESCO Campus, Ebonyi State University, Abakaliki, Nigeria

Study’s Novelty/Excerpt This study investigates the bacterial contamination of borehole water at Presco campus, Ebonyi State University, Abakaliki, focusing on the identified bacteria's isolation, characterization, and antibiotic susceptibility. The research is unique in its detailed analysis of the antibiotic resistance patterns of Shigella and Salmonella species, revealing significant resistance to commonly used antibiotics like Trimethoprim-Sulphamethoxazole and Tetracycline, while also identifying effective antibiotics such as Ceftriaxone and Levofloxacin. These findings highlight the public health risks associated with contaminated borehole water and emphasize the need for regular monitoring and appropriate water treatment measures to ensure safe drinking water for the community. Full Abstract Water is essential for life. An adequate, safe, and accessible water supply must be available to all. Hence, this research aimed to isolate and characterize bacteria from borehole water samples located at the Presco campus, Ebonyi State University, Abakaliki, and test the antibiotic susceptibility patterns of the bacteria isolated. Twelve (12) water samples were collected from six (6) locations in duplicates and analyzed using standard microbiological methods. Serial dilutions were performed on the samples and dilutions of 103 were plated using the pour plate method. After the incubation periods, colonies were counted and expressed in CFU/mL, biochemical tests were carried out and the antibiotics susceptibility profiles of the bacteria isolated were evaluated. From the results, the total microbial counts ranged from 1.0 x 104 to 5.9 x 104 CFU/mL, indicating high contamination of the water samples. The morphology and biochemical tests revealed the presence of Shigella species 5 (45.4 %) and Salmonella species 6 (54.6 %). Shigella species were highly resistant to both Trimethoprim-Sulphamethoxazole and Amoxicillin (80 %) and to Tetracycline (100 %) but were susceptible to Ceftriaxone (100 %) and Ciprofloxacin (80 %). On the other hand, Salmonella species showed a resistant pattern of 83.3 % to Tetracycline, Ciprofloxacin, and Ceftriaxone but were susceptible to Levofloxacin (100 %) and Cefepime (83.3 %). This result is of public health importance as these organisms can threaten individuals utilizing these boreholes as the source of drinking water.

Determination of Bacterial Species Associated with Contamination of Poultry Feeds Produced by Three Different Companies in Abuja, Nigeria

Poultry farming is an efficient source of income and nutrition. Feeds used for poultry are vulnerable to contamination by microorganisms. This study aimed to assess bacterial contaminants of the poultry produced from three different companies in Abuja, Nigeria. Samples of poultry feeds produced by three different companies were collected from three different batches and were processed and inoculated in nutrient agar, Eosin methylene blue agar (EMB), and Mannitol salt agar (MSA), incubated at 37 °C for 24 hours. Colonies were counted, characterized, and subcultured to obtain pure cultures. Pure isolates were identified using Gram reaction, cellular morphology, and biochemical characteristics. Antibiotic susceptibility profiles of the isolated bacterial species were determined using Kirby-Bauer disc diffusion. The total bacterial counts of samples analyzed showed that poultry feed from sample C had the highest mean bacterial counts of 2.49 x 105CFU/g. The lowest was poultry feed sample A, with a mean count of 1.06 x 105CFU/g. Sample B had a mean bacterial count of 2.14 x 105CFU/g. The bacterial species isolated in the present study are Staphylococcus aureus, Escherichia coli, Salmonella sp., and Proteus mirabilis. Staphylococcus aureus was the most occurring isolate with a 47% occurrence rate and was present in all poultry feed samples. Escherichia coli is the second most occurring with a 35% occurrence rate, then Salmonella with a 10% occurrence rate. The least occurring was Proteus mirabilis, with an 8% occurrence rate. S. aureus showed 100% susceptibility to all the antibiotics used, while P. mirabilis recorded the highest resistance of 40 %, showing resistance to four of the ten antibiotics used. This study reveals the presence and high microbial count in the different poultry feeds investigated. This usually reflects the degree of hygienic procedures and biosecurity used in the feeds' handling, production, and storage.

Microbiological profile and antimicrobial susceptibility of bacteria associated with urinary tract infections in Ukrainian adults

The aim of the study was to analyse the microbial profile of the urinary tract infections (UTIs) due to urolithiases and to study susceptibility to antibiotics in its causative agents. The main method of the research was bacteriological. Antimicrobial susceptibility testing was conducted by serial microdilution assay in accordance with recommendations of the European committee on antimicrobial susceptibility testing (EUCAST). For present study 128 unique urine samples were collected from patients with UTIs associated with urolithiasis. Among all collected specimens, 78% (n=100) gave clinically signi­ficant growth. Among all examined participants, 88.9% of women (64/72) and 64.3% of men (36/56) had confirmed UTI; in the study, female/male ratio was 1.4 (χ2=9.76; p&lt;0.05). Microorganisms identified in our study predominantly belon­ged to Bacteria (93.4%), and yeasts of Candida genus comprised only 6.6%. Among all, 66.1% were representatives of Enterobacterales (n=80), particularly, Escherichia coli (38.0%), Klebsiella oxytoca (15.7%), Klebsiella pneumoniae (2.5%), Enterobacter cloacae (5.8%), Proteus mirabilis (4.1%). Isolates of Pseudomonas aeruginosa comprised 3.3%. Among gram-positive isolates, Staphylococcus spp. (14.1%) and Enterococcus spp. (9.9%) were identified. Regarding female/male distribution, the biggest proportion of gram-positive bacteria were isolated from women, statistically significant results were obtained for sex distribution of S. saprophyticus (p&lt;0.05). Antimicrobial susceptibility of Enterobacterales was variable, and the best results were obtained for carbapenems, novel antibiotics (cefiderocol, ceftolozane-tazobactam and ceftazidime-avibactam), aminoglycosides and tigecycline. There were 9 isolates with pro­duction of carbapenemases and resistant to all relevant β-lactam antibiotics. All isolated Staphylococcus spp. were β-lactamase producers, one isolate of S. saprophyticus demonstrated methicillin-resistance. To summarise, there is an ongoing outbreak of multidrug-resistant infections in Ukraine and causative agents of UTIs are among the most important contributors. Availability of data on the local antimicrobial susceptibility profile may guide the informed decision making in etiotropic treatment, therefore, contribute to global efforts in rational drug use and fight the resistance escalation.

A Label-Free Optical Flow Cytometry Based-Method for Rapid Assay of Disinfectants' Bactericidal Activity.

Selecting the appropriate disinfectant to control and prevent healthcare-associated infections (HAIs) is a challenging task for environmental health experts due to the large number of available disinfectant products. This study aimed to develop a label-free flow cytometry (FCM) method for the rapid evaluation of bactericidal activity and to compare its efficacy with that of standard qualitative/quantitative suspension tests. The bactericidal efficiency of eight commercial disinfectants containing quaternary ammonium compounds (QACs) was evaluated against four strains recommended by EN 13727 (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Enterococcus hirae) and four multidrug-resistant pathogens. The proposed FCM protocol measures changes in scattered light and counts following disinfectant exposure, neutralization, and culture steps. Unlike other available FCM-based methods, this approach does not rely on autofluorescence measurements, impedance cytometry, or fluorescent dyes. The FCM scattered light signals revealed both decreased count rates and morphological changes after treatment with minimum inhibitory concentrations (MICs) and higher concentrations for all tested bacteria. The results from the FCM measurements showed excellent correlation with those from standard assays, providing a rapid tool for monitoring the susceptibility profile of clinical, multidrug-resistant pathogens to chemical disinfectants, which could support infection prevention and control procedures for healthcare environments. This label-free FCM protocol offers a novel and rapid tool for environmental health experts, aiding in the optimization of disinfectant selection for the prevention and control of HAIs.

Four novel Acinetobacter lwoffii strains isolated from the milk of cows in China with subclinical mastitis

BackgroundAcinetobacter lwoffii (A. lwoffii) is a Gram-negative bacteria common in the environment, and it is the normal flora in human respiratory and digestive tracts. The bacteria is a zoonotic and opportunistic pathogen that causes various infections, including nosocomial infections. The aim of this study was to identify A. lwoffii strains isolated from bovine milk with subclinical mastitis in China and get a better understanding of its antimicrobial susceptibility and resistance profile. This is the first study to analyze the drug resistance spectrum and corresponding mechanisms of A. lwoffii isolated in raw milk.ResultsFour A. lwoffii strains were isolated by PCR method. Genetic evolution analysis using the neighbor-joining method showed that the four strains had a high homology with Acinetobacter lwoffii. The strains were resistant to several antibiotics and carried 17 drug-resistance genes across them. Specifically, among 23 antibiotics, the strains were completely susceptible to 6 antibiotics, including doxycycline, erythromycin, polymyxin, clindamycin, imipenem, and meropenem. In addition, the strains showed variable resistance patterns. A total of 17 resistance genes, including plasmid-mediated resistance genes, were detected across the four strains. These genes mediated resistance to 5 classes of antimicrobials, including beta-lactam, aminoglycosides, fluoroquinolones, tetracycline, sulfonamides, and chloramphenicol.ConclusionThese findings indicated that multi-drug resistant Acinetobacter lwoffii strains exist in raw milk of bovine with subclinical mastitis. Acinetobacter lwoffii are widespread in natural environmental samples, including water, soil, bathtub, soap box, skin, pharynx, conjunctiva, saliva, gastrointestinal tract, and vaginal secretions. The strains carry resistance genes in mobile genetic elements to enhance the spread of these genes. Therefore, more attention should be paid to epidemiological surveillance and drug resistant A. lwoffii.

Investigation of Healthcare-Acquired Infections and Antimicrobial Resistance in an Italian Hematology Department before and during the COVID-19 Pandemic.

The COVID-19 pandemic has made antibiotic resistance (AMR) and healthcare-acquired infections (HAIs) increasingly serious problems. Point-prevalence Surveys (PPS) and other surveillance techniques are essential for antimicrobial management and prevention. In a hematology department of an Italian hospital, the prevalence of HAI, microbiology, and AMR were examined in this retrospective study in two different periods, namely 2019 and 2021 (pre-pandemic and during the pandemic, respectively). Comparisons were made between patient demographics, hospitalization duration, surveillance swabs, and HAIs. There was no discernible variation in the prevalence of HAI between 2019 and 2021. Higher rates of HAI were connected with longer hospital stays. Variations in antimicrobial susceptibility and species distribution were found by microbiological analysis. The incidence of HAI stayed constant during the epidemic. Nevertheless, shifts in antibiotic susceptibility and microbiological profiles highlight the necessity of continuous monitoring and care. Despite the difficulties of COVID-19, ongoing surveillance and infection control initiatives are crucial for halting HAIs and battling antimicrobial resistance (AMR) in healthcare environments. To fully understand the pandemic's long-term impact on the spread of infectious diseases and antibiotic resistance, more research is required.

Genome-wide polygenic risk scores predict risk of glioma and molecular subtypes.

Polygenic risk scores (PRS) aggregate the contribution of many risk variants to provide a personalized genetic susceptibility profile. Since sample sizes of glioma genome-wide association studies (GWAS) remain modest, there is a need to efficiently capture genetic risk using available data. We applied a method based on continuous shrinkage priors (PRS-CS) to model the joint effects of over 1 million common variants on disease risk and compared this to an approach (PRS-CT) that only selects a limited set of independent variants that reach genome-wide significance (P < 5 × 10-8). PRS models were trained using GWAS stratified by histological (10 346 cases and 14 687 controls) and molecular subtype (2632 cases and 2445 controls), and validated in 2 independent cohorts. PRS-CS was generally more predictive than PRS-CT with a median increase in explained variance (R2) of 24% (interquartile range = 11-30%) across glioma subtypes. Improvements were pronounced for glioblastoma (GBM), with PRS-CS yielding larger odds ratios (OR) per standard deviation (SD) (OR = 1.93, P = 2.0 × 10-54 vs. OR = 1.83, P = 9.4 × 10-50) and higher explained variance (R2 = 2.82% vs. R2 = 2.56%). Individuals in the 80th percentile of the PRS-CS distribution had a significantly higher risk of GBM (0.107%) at age 60 compared to those with average PRS (0.046%, P = 2.4 × 10-12). Lifetime absolute risk reached 1.18% for glioma and 0.76% for IDH wildtype tumors for individuals in the 95th PRS percentile. PRS-CS augmented the classification of IDH mutation status in cases when added to demographic factors (AUC = 0.839 vs. AUC = 0.895, PΔAUC = 6.8 × 10-9). Genome-wide PRS has the potential to enhance the detection of high-risk individuals and help distinguish between prognostic glioma subtypes.

Susceptibility evaluation of novel beta-lactam/beta-lactamase inhibitor combinations against carbapenem-resistant Klebsiella pneumoniae from bloodstream infections in hospitalized patients in Brazil

IntroductionNovel beta-lactam/beta-lactamase inhibitor (BIBLI) combinations are commercially available and have been used for treating carbapenem-resistant Klebsiella pneumoniae (CRKP) infections. Continuous surveillance of susceptibility profiles and resistance mechanism identification are necessary to monitor the evolution of resistance within these agents. ObjectiveThe purpose of this study was to evaluate the susceptibility rates of ceftazidime/avibactam, imipenem/relebactam and meropenem/vaborbactam in CRKP isolated from patients with bloodstream infections who underwent screening for a randomized clinical trial in Brazil. MethodsMinimum inhibitory concentrations (MICs) were determined for meropenem, ceftazidime/avibactam, imipenem/relebactam and meropenem/vaborbactam using the gradient diffusion strip method. Carbapenemase genes were detected by multiplex real-time polymerase chain reaction. Klebsiella pneumoniae carbapenemase (KPC)-producing isolates showing resistance to any BLBLI and New Delhi Metallo-beta-lactamase (NDM)-producing isolates with susceptibility to any BLBLI isolates were further submitted for whole-genome sequencing. ResultsFrom a total of 69 CRKP isolates, 39 were positive for blaKPC, 19 for blaNDM and 11 for blaKPC and blaNDM. KPC-producing isolates demonstrated susceptibility rates above 94 % for all BLBLIs. Two isolates with resistance to meropenem/vaborbactam demonstrated a Gly and Asp duplication at the porin OmpK36 as well as a truncated OmpK35. All NDM-producing isolates, including KPC and NDM coproducers, demonstrated susceptibility rates to ceftazidime/avibactam, imipenem/relebactam and meropenem/vaborbactam of 0 %, 9.1–21.1 % and 9.1–26.3 %, respectively. Five NDM-producing isolates that presented susceptibility to BLBLIs also had porin alterations ConclusionsThis study showed that, although high susceptibility rates to BLBLIs were found, KPC-2 isolates were able to demonstrate resistance probably as a result of porin mutations. Additionally, NDM-1 isolates showed susceptibility to BLBLIs in vitro.

Clinical and mycological analysis of colonization by Candida spp. in oral leukoplakia and oral lichen planus.

This study aims to analyze the prevalence of Candida spp. colonization in oral leukoplakia and oral lichen planus lesions, verify the influence of systemic and local factors, besides identify and determine the in vitro antifungal susceptibility profile of Candida species. Samples were collected by swabbing from oral lesions and healthy mucosa and cultured on Sabouraud Dextrose and CHROMagar® Candida plates. Species identification was confirmed with MALDI-TOF MS analysis. Candida spp. was found in 36.8% of cases of oral leukoplakia and 18.2% of cases of oral lichen planus. Candida albicans was the only species found in oral lichen planus lesions (n = 2, 100%) and the most prevalent in oral leukoplakia (n = 5, 76.4%). Among the non-albicans Candida species found in oral leukoplakia were C. parapsilosis (n = 2, 25.5%) and C. tropicalis (n = 1, 14.1%). Candida isolates were susceptible to all antifungals tested. C. albicans was the most commonly found species in the studied lesions. No correlation was found between systemic and local factors with positive cases of oral lichen planus. However, smoking and alcohol consumption may be associated with positive cases of oral leukoplakia, especially the non-homogeneous clinical form. In addition, there is a possible predisposition to associated Candida colonization in cases of epithelial dysplasia found in oral leukoplakia. The antifungal medications tested showed excellent efficacy against isolates.

The usefulness of the magnetic susceptibility of loess paleosol sequences for paleoclimate and stratigraphic studies: The case of the Quaternary Palouse loess, northwestern United States

Worldwide, Quaternary loess-paleosol sequences archive terrestrial paleoenvironmental information. The Palouse loess in the northwestern USA is one such deposit representing at least a million years of sediment accumulation. Loess paleosol sequences are often studied via the magnetic susceptibility of sediments and the changes in susceptibility with depth. However, since variations in magnetic susceptibility can have different underlying causes, the interpretation of the magnetic susceptibility of loess depends on factors specific to each major loess region. We measured the magnetic susceptibility of sediments along depth profiles in a well-studied exposure of the Palouse loess in eastern Washington, USA (the “CLY-2 site,” 46.3131° N, 118.4874° W, WGS84). Our measurements show that the magnetic susceptibility of sediments in the Palouse loess varies systematically and predictably with depth and can be correlated with other magnetic susceptibility profiles at the outcrop scale and at the regional scale. We also measured changes in grain size, elemental abundance, mineralogy, and other magnetic properties to determine the most likely cause of the magnetic susceptibility signal. Based on these results, variations in magnetic susceptibility in the Palouse are likely driven mostly by changes in coarse sediment supply and accumulation of tephra rather than changes in weathering. Magnetic susceptibility is useful as an inexpensive, non-destructive tool for stratigraphic correlation of Quaternary loess deposits in the Palouse, especially in combination with paleosol stratigraphic markers and known tephra deposits.

Biomonitoring Environmental Exposure in Syrian Refugees in Lebanon.

Over one million Syrian refugees have been residing in substandard living conditions in Lebanon for the past decade. Non-invasive biomonitoring of fractional exhaled nitric oxide (FeNO) as a pulmonary inflammation biomarker was conducted following and preceding indoor environmental assessments (which revealed elevated mould counts in informal tented settlements and non-residential shelters) to further evaluate effects of environmental exposure to indoor contaminants. Results of biomonitoring (n = 57) provided some insight regarding existing respiratory conditions and the possible implementation of minimally invasive methods to establish susceptibility profiles in Syrian refugees amid limited access to healthcare. The clinical interpretation of FeNO results suggested possible persistent exposure to allergens in addition to significant type 2 inflammation in some subjects. These findings warrant the need to expand this study, investigate other biomarkers, and attempt to correlate findings with environmental conditions to evaluate if a dose-response relationship exists.

Characterization and Genome Analysis of the Delftia lacustris Strain LzhVag01 Isolated from Vaginal Discharge

Delftia has been separated from freshwater, sludge, and soil and has emerged as a novel opportunistic pathogen in the female vagina. However, the genomic characteristics, pathogenicity, and biotechnological properties still need to be comprehensively investigated. In this study, a Delftia strain was isolated from the vaginal discharge of a 43-year-old female with histologically confirmed cervical intraepithelial neoplasm (CIN III), followed by whole-genome sequencing. Phylogenetic analysis and average nucleotide identity (ANI) analysis demonstrated that it belongs to Delftia lacustris, named D. lacustris strain LzhVag01. LzhVag01 was sensitive to β-lactams, macrolides, and tetracyclines but exhibited resistance to lincoamines, nitroimidazoles, aminoglycosides, and fluoroquinolones. Its genome is a single, circular chromosome of 6,740,460 bp with an average GC content of 66.59%. Whole-genome analysis identified 16 antibiotic resistance-related genes, which match the antimicrobial susceptibility profile of this strain, and 11 potential virulence genes. These pathogenic factors may contribute to its colonization in the vaginal environment and its adaptation and accelerate the progression of cervical cancer. This study sequenced and characterized the whole-genome of Delftia lacustris isolated from vaginal discharge, which provides investigators and clinicians with valuable insights into this uncommon species.