Monitoring the transition from corneal ulceration to healed scar using a Scheimpflug tomography-based densitometry.

PURPOSE: To compare corneal haze between active ulcer and healed scarring using a Scheimpflug densitometry. MATERIALS AND METHODS: A prospective longitudinal study enrolled 30 patients (30 eyes) with ulcerative keratitis (UK). Each subject's corneal optical density (COD) was measured with a Scheimpflug corneal densitometry, Pentacam® AXL (Oculus GmbH, Wetzlar, Germany), at the active ulcerative and complete scarring stage. The COD data were analyzed through distinct methods (inbuilt, sorted annular partitions, and ulcer-matching densitometric maps). We compared different CODs to select the better index for clinically monitoring the transition from corneal ulceration to healed scar. RESULTS: The CODs of the periphery (P = 0.0024) and outside of the active ulcer (P = 0.0002) significantly decreased after scarring. Partitioning the cornea into different depths and annular zones, the anterior layer, center layer, and the 2-6 mm annular zone had a more remarkable COD decrease after scar formation. The 3rd-sorted COD in the anterior layer revealed the highest area under the receiver-operating characteristic curves (0.709), in which 90% of subjects had COD reduction during the ulcer-to-scar transition. CONCLUSIONS: Aside from subjective judgment based on clinical signs, the Scheimpflug tomography-based densitometry could provide objective and efficient monitoring of the corneal opacity evolution in UK patients. Because the 3rd-sorted annular COD is a better index than the inbuilt or mapping CODs in differentiating active ulcers from healed scars, this COD could be a clinically promising parameter to monitor the progression of UK patients.

The Impact of Cefuroxime Susceptibility on Aeromonas Necrotizing Fasciitis Outcomes.

Despite aggressive antibiotic therapy and surgical debridement, Aeromonas necrotizing fasciitis (NF) can lead to high amputation and mortality rates. Our study compares the different antibiotic minimum inhibitory concentrations (MICs) via Epsilometer tests (E-tests) between non-survivors and survivors of Aeromonas NF of limbs. A prospective review of 16 patients with Aeromonas NF was conducted for 3.5 years in a tertiary coastal hospital. E-tests were conducted for 15 antimicrobial agents to determine the MIC value for Aeromonas species. These patients were divided into non-survival and survival groups. The clinical outcomes, demographics, comorbidities, presenting signs and symptoms, laboratory findings, and microbiological results between the two periods were compared. A total of four patients died, whereas 12 survived, resulting in a 25% mortality rate. A higher proportion of bloodstream infections (100% vs. 41.7%; p = 0.042), monomicrobial infections (100% vs. 33.3%; p = 0.021), shock (100% vs. 33.3%; p = 0.021), serous bullae (50% vs. 0%; p = 0.009), liver cirrhosis (100% vs. 25%; p = 0.009), chronic kidney disease (100% vs. 33.3%; p = 0.021), lower susceptibility to cefuroxime (25% vs. 83.3%; p = 0.028), and ineffective antibiotic prescriptions (75% vs. 16.7%; p = 0.029) was observed in non-survivors. Aeromonas NF is an extremely rare skin and soft-tissue infection that is associated with high mortality, bacteremia, antibiotic resistance, and polymicrobial infection. Therefore, antibiotic regimen selection is rendered very challenging. To improve clinical outcomes and irrational antimicrobial usage, experienced microbiologists can help physicians identify specific pathogens and test MIC.

Initial skin necrosis presentation at emergency room was associated with fulminant clinical course and mortality in patients with Vibrio necrotizing fasciitis.

Necrotizing fasciitis (NF) is a life-threatening infection. Skin necrosis is an important skin sign of NF. The purposes of this study was to investigate the initial skin conditions of Vibrio NF patients between emergency room (ER) to preoperative status, to compare the clinical and laboratory risk indicators of the skin necrosis group and non-skin necrosis group when they arrived at ER, and to evaluate whether initial cutaneous necrosis related to fulminant course and higher fatalities. From 2015 to 2019, seventy-two Vibrio NF patients with surgical confirmation were enrolled. We identified 25 patients for inclusion in the skin necrosis group and 47 patients for inclusion in the non-skin necrosis group due to the appearance of skin lesion at ER. Seven patients died, resulting in a mortality rate of 9.7%. Six patients of skin necrosis group and one patient of non-skin necrosis group died, which revealed the skin necrosis group had a significantly higher mortality rate than the non-skin necrosis group. All the patients in the skin necrosis group and 30 patients of non-skin necrosis group developed serous or hemorrhagic bullous lesions before operation (p = 0.0003). The skin necrosis group had a significantly higher incidence of APACHE score, postoperative intubation, Intensive care unit stay, septic shock, leukopenia, higher counts of banded leukocytes, elevated C-reactive protein (CRP), and lower serum albumin level. Vibrio NF patients presenting skin necrosis at ER were significantly associated with fulminant clinical courses and higher mortality. Physicians should alert the appearance of skin necrosis at ER to early suspect NF and treat aggressively by those clinical and laboratory risk indicators, such as elevated APACHE score, shock, leukopenia, higher banded leukocytes, elevated CRP, and hypoalbuminia.

Clinical manifestations and outcome of nocardiosis and antimicrobial susceptibility of Nocardia species in southern Taiwan, 2011-2021.

BACKGROUND/PURPOSE: Nocardiosis is an uncommon infectious disease. This study aimed to assess the clinical outcome of patients with nocardiosis and examine the antimicrobial susceptibility profiles of Nocardia spp. isolated. METHODS: We retrospectively reviewed the medical records of all inpatients diagnosed with nocardiosis between 2011 and 2021. The identification of Nocardia spp. at the species level was performed with the use of MALDI-TOF and 16S rRNA assays. The antimicrobial susceptibility of Nocardia spp. was performed using the microbroth dilution method. Factors associated with 90-day all-cause mortality were identified in multivariate logistic regression analysis. RESULTS: Of 60 patients with nocardiosis in the 11-year study period, the lungs (55.0%) were the most common site of involvement, followed by the skin and soft tissue (45.0%). Twenty-two patients (36.7%) died within 90 days following the diagnosis. All of the Nocardia isolates were susceptible to trimethoprim-sulfamethoxazole, linezolid, and amikacin, whereas more than 70% of the isolates were not susceptible to ciprofloxacin, imipenem-cilastatin, moxifloxacin, cefepime, and clarithromycin. Nocardiosis involving the lungs (relative risk [RR], 9.99; 95% confidence interval [CI], 1.52-65.50; p = 0.02), nocardiosis involving the skin and soft tissue (RR, 0.15; 95% CI, 0.02-0.92; p = 0.04), and treatment with trimethoprim-sulfamethoxazole (RR, 0.14; 95% CI, 0.03-0.67; p = 0.01) were independently associated with 90-day all-cause mortality. CONCLUSIONS: Nocardia spp. identified between 2011 and 2021 remained fully susceptible to trimethoprim-sulfamethoxazole, linezolid, and amikacin. Nocardiosis of the lungs, skin and soft tissue infection, and treatment with trimethoprim-sulfamethoxazole were independently associated with 90-day all-cause mortality.

Rational Use of Antibiotics and Education Improved Aeromonas Necrotizing Fasciitis Outcomes in Taiwan: A 19-Year Experience.

BACKGROUND: Aeromonas necrotizing fasciitis (NF) causes high rates of amputation and mortality, even after aggressive surgical debridement and antibacterial therapy. This study investigated the effects of rational use of antibiotics and education by infectious disease (ID) physicians on Aeromonas NF treatment outcomes. METHODS: Retrospective review for conducted for four years (period I, without an ID physician, December 2001 to December 2005) and 15 years (period II, with an ID physician, January 2006 to March 2021). In period II, the hospital-wide computerized antimicrobial approval system (HCAAS) was also implemented. A pretest-posttest time series analysis compared the two periods. Differences in clinical outcomes, demographics, comorbidities, signs and symptoms, laboratory findings, Aeromonas antibiotic susceptibility, and antibiotic regimens were compared between the two periods. RESULTS: There were 19 patients in period I and 53 patients in period II. Patients had a lower rate of amputation or mortality in period II (35.8%) compared with period I (63.2%). Forty-four patients (61.1%) had polymicrobial infections. In the emergency room, the rate of misdiagnosis decreased from 47.4% in period I to 28.3% in period II, while effective empiric antibiotic usage increased from 21.1% in period I to 66.0% in period II. After the ID physician's adjustment, 69.4% received monotherapy in period II compared to 33.3% in period I. CONCLUSIONS: Because Aeromonas NF had a high mortality rate and was often polymicrobial, choosing an antibiotic regimen was difficult. Using the HCAAS by an experienced ID physician can improve rational antibiotic usage and clinical outcomes in Aeromonas NF.

Epidemiology of Nocardia Species at a Tertiary Hospital in Southern Taiwan, 2012 to 2020: MLSA Phylogeny and Antimicrobial Susceptibility.

The identification and antimicrobial susceptibility of Nocardia spp. are essential for guiding antibiotic treatment. We investigated the species distribution and evaluated the antimicrobial susceptibility of Nocardia species collected in southern Taiwan from 2012 to 2020. A total of 77 Nocardia isolates were collected and identified to the species level using multi-locus sequence analysis (MLSA). The susceptibilities to 15 antibiotics for Nocardia isolates were determined by the broth microdilution method, and the MIC50 and MIC90 for each antibiotic against different species were analyzed. N. cyriacigeorgica was the leading isolate, accounting for 32.5% of all Nocardia isolates, and the prevalence of Nocardia isolates decreased in summer. All of the isolates were susceptible to trimethoprim/sulfamethoxazole, amikacin, and linezolid, whereas 90.9% were non-susceptible to cefepime and imipenem. The phylogenic tree by MLSA showed that the similarity between N. beijingensis and N. asiatica was as high as 99%, 73% between N. niigatensis and N. crassostreae, and 86% between N. cerradoensis and N. cyriacigeorgica. While trimethoprim/sulfamethoxazole, amikacin, and linezolid remained fully active against all of the Nocardia isolates tested, 90.9% of the isolates were non-susceptible to cefepime and imipenem.

Air Sampling for Fungus around Hospitalized Patients with Coronavirus Disease 2019.

The risk of developing coronavirus disease 2019 (COVID-19)-associated pulmonary aspergillosis (CAPA) depends on factors related to the host, virus, and treatment. However, many hospitals have modified their existing rooms and adjusted airflow to protect healthcare workers from aerosolization, which may increase the risk of Aspergillus exposure. This study aimed to quantitatively investigate airborne fungal levels in negative and slightly negative pressure rooms for COVID-19 patients. The air in neutral pressure rooms in ordinary wards and a liver intensive care unit with high-efficiency particulate air filter was also assessed for comparison. We found the highest airborne fungal burden in recently renovated slightly negative air pressure rooms, and a higher airborne fungal concentration in both areas used to treat COVID-19 patients. The result provided evidence of the potential environmental risk of CAPA by quantitative microbiologic air sampling, which was scarcely addressed in the literature. Enhancing environmental infection control measures to minimize exposure to fungal spores should be considered. However, the clinical implications of a periodic basis to determine indoor airborne fungal levels and further air sterilization in these areas remain to be defined.

Epidemiological and Clinical Characteristics, Antifungal Susceptibility, and MLST-Based Genetic Analysis of Cryptococcus Isolates in Southern Taiwan in 2013-2020.

Cryptococcal meningoencephalitis (CM) is a treatable condition, but it leads to excessive morbidity and mortality. We collected 115 non-duplicated Cryptococcus clinical isolates during 2013−2020 in southern Taiwan to perform antifungal susceptibility testing. Multi-locus sequence typing was performed on 96 strains from patients with CM (n = 47) or cryptococcemia (n = 49). In addition, the epidemiological and clinical characteristics of patients with CM during 2013−2020 (n = 47) were compared with those during 2000−2010 (n = 46). During 2013−2020, only one C. neoformans isolate (0.9%) had a fluconazole minimum inhibitory concentration of >8 µg/mL. Amphotericin B (AMB), flucytosine (5FC), and voriconazole were highly active against all C. neoformans/C. gattii isolates. The most common sequence type was ST5. Among these 47 patients with CM, cerebrospinal fluid cryptococcal antigen (CSF CrAg) titer >1024 was a significant predictor of death (odds ratio, 48.33; 95% CI, 5.17−452.06). A standard induction therapy regimen with AMB and 5FC was used for all patients during 2013−2020, but only for 2.2% of patients in 2000−2010. The in-hospital CM mortality rate declined from 39.1% during 2000−2010 to 25.5% during 2013−2020, despite there being significantly younger patients with less CSF CrAg >1024 during 2000−2010. The study provides insight into the genetic epidemiology and antifungal susceptibility of Cryptococcus strains in southern Taiwan. The recommended antifungal drugs, AMB, 5FC, and FCZ, remained active against most of the Cryptococcus strains. Early diagnosis of patients with CM and adherence to the clinical practice guidelines cannot be overemphasized to improve the outcomes of patients with CM.

Diagnosing Fungal Keratitis and Simultaneously Identifying Fusarium and Aspergillus Keratitis with a Dot Hybridization Array.

Fungal keratitis (FK) is one of the most common microbial keratitis, which often leads to poor prognosis as a result of delayed diagnosis. Several studies implied that early differentiation of the two major FK, Fusarium and Aspergillus keratitis, could be helpful in selecting effective anti-fungal regimens. Therefore, a novel dot hybridization array (DHA) was developed to diagnose FK and differentiate Fusarium and Aspergillus keratitis in this study. One hundred forty-six corneal scrapes obtained from one hundred forty-six subjects impressed with clinically suspected FK were used to evaluate the performance of the DHA. Among these patients, 107 (73.3%) patients had actual FK confirmed by culture and DNA sequencing. We found that the DHA had 93.5% sensitivity and 97.4% specificity in diagnosing FK. In addition, this array had 93.2% sensitivity and 93.8% specificity in diagnosing Fusarium keratitis, as well as 83.3% sensitivity and 100% specificity in diagnosing Aspergillus keratitis. Furthermore, it had 83.9% sensitivity and 100% specificity in identifying Fusarium solani keratitis. Thus, this newly developed DHA will be beneficial to earlier diagnosis, more precise treatment, and improve prognosis of FK, by minimizing medical refractory events and surgical needs.

Tear Proteomics Study of Dry Eye Disease: Which Eye Do You Adopt as the Representative Eye for the Study?

Most studies about dry eye disease (DED) chose unilateral eye for investigation and drew conclusions based on monocular results, whereas most studies involving tear proteomics were based on the results of pooling tears from a group of DED patients. Patients with DED were consecutively enrolled for binocular clinical tests, tear biochemical markers of DED, and tear proteome. We found that bilateral eyes of DED patients may have similar but different ocular surface performance and tear proteome. Most ocular surface homeostatic markers and tear biomarkers were not significantly different in the bilateral eyes of DED subjects, and most clinical parameters and tear biomarkers were correlated significantly between bilateral eyes. However, discrepant binocular presentation in the markers of ocular surface homeostasis and the associations with tear proteins suggested that one eye's performance cannot represent that of the other eye or both eyes. Therefore, in studies for elucidating tear film homeostasis of DED, we may lose some important messages hidden in the fellow eye if we collected clinical and proteomic data only from a unilateral eye. For mechanistic studies, it is recommended that researchers collect tear samples from the eye with more severe DED under sensitive criteria for identifying the more severe eye and evaluating the tear biochemical and proteomic markers with binocular concordance drawn in prior binocular studies.

A Genomic Approach to Investigating Ocular Surface Microorganisms: Monitoring Core Microbiota on Eyelid Margin with a Dot hybridization Assay.

A sound ocular surface microbiota has been recognized as a part of ocular surface health following a growing body of evidence from next-generation sequencing technique and metagenomic analysis. However, even from the perspective of contemporary precision medicine, it is difficult to directly apply these new technologies to clinical practice. Therefore, we proposed a model based on dot hybridization assay (DHA) to bridge conventional culture with a metagenomic approach in investigating and monitoring ocular surface microbiota. Endophthalmitis, mostly caused by bacterial infection, is the most severe complication of many intraocular surgeries, such as cataract surgery. Hazardous microorganisms hiding and proliferating in the ocular surface microbiota not only increase the risk of endophthalmitis but also jeopardize the effectiveness of the preoperative aseptic procedure and postoperative topical antibiotics. The DHA model enables the simultaneous assessment of bacterial bioburden, detection of target pathogens and microorganisms, and surveillance of methicillin/oxacillin resistance gene mecA in the ocular surface microbiota. This assay revealed heavier bacterial bioburden in men, compatible with a higher risk of endophthalmitis in male patients who underwent cataract surgery. No occurrence of endophthalmitis for these patients was compatible with non-hazardous microorganisms identified by specific dots for target pathogens. Moreover, the mecA dot detected oxacillin-resistant strains, of which culture failed to isolate. Therefore, the DHA model could provide an alternative genomic approach to investigate and monitor ocular surface microorganisms in clinical practice nowadays.

Azole resistance in Aspergillus species in Southern Taiwan: An epidemiological surveillance study.

Poor clinical outcomes for invasive aspergillosis are associated with antifungal resistance. Performing antifungal susceptibility tests on clinically relevant Aspergillus isolates from patients and environmental regions with known azole resistance is recommended. The aim of the study was to assess the presence of azole resistance in clinical Aspergillus spp. isolates and those from hospital environments and farmlands within a 40 km radius of the hospital. Clinical Aspergillus spp. isolates were cultured, as well as environmental Aspergillus spp. isolates obtained from air samples. Samples were subcultured in azole-containing agar plates. Isolates with a positive screening test were subjected to YeastOne methods to determine their minimum inhibitory concentrations of antifungals. Resistance mechanisms were investigated in the azole-resistant Aspergillus spp. isolates. No azole-resistant clinical or environmental A flavus, A oryaze, A niger or A terreus isolates were found in the present study. All A fumigatus clinical isolates were azole-susceptible. Seven A fumigatus environmental isolates were associated with cyp51A mutations, including two that harboured TR34 /L98H mutations with S297T/F495I substitutions, two with TR34 /L98H mutations and three with TR46 /Y121F/T289A mutations. One of these isolates was collected from farmland, one was from A ward and five were from B ward. The proportion of azole-resistant A fumigatus was 10.2% (6/59) and 3.2% (1/31) in the hospital environments and the farmlands near the hospital, respectively. The results showed that azole-resistant A fumigatus existed within hospital environments. This emphasises the importance of periodic surveillance in hospital environments and monitoring for the emergence of azole-resistant A fumigatus clinical isolates.

The Impact of Biofilm Formation on the Persistence of Candidemia.

This study aimed to determine the predictors of persistent candidemia and examine the impact of biofilm formation by Candida isolates in adult patients with candidemia. Of the adult patients with candidemia in Kaohsiung Chang Gung Memorial Hospital between January 2007 and December 2012, 68 case patients with persistent candidemia (repeated candidemia after a 3-day systemic antifungal therapy) and 68 control patients with non-persistent candidemia (Candida clearance from the bloodstream after a 3-day systemic antifungal therapy) were included based on propensity score matching and matching for the Candida species isolated. Biofilm formation by the Candida species was assessed in vitro using standard biomass assays. Presence of central venous catheters (CVCs) at diagnosis (adjusted odd ratio [AOR], 3.77; 95% confidence interval [CI], 1.09-13.00, p = 0.04), infection with higher biofilm forming strains of Candida species (AOR, 8.03; 95% CI, 2.50-25.81; p < 0.01), and receipt of suboptimal fluconazole doses as initial therapy (AOR, 5.54; 95% CI, 1.53-20.10; p < 0.01) were independently associated with persistent candidemia. Biofilm formation by Candida albicans, C. tropicalis, and C. glabrata strains was significantly higher in the case patients than in the controls. There were no significant differences in the overall mortality and duration of hospitalization between the two groups. Our data suggest that, other than presence of retained CVCs and use of suboptimal doses of fluconazole, biofilm formation was highly associated with development of persistent candidemia.

Antimicrobial Susceptibility and Virulence Surveillance of Campylobacter spp. Isolated From Patients in Two Tertiary Medical Centers in Taiwan.

Campylobacter spp. may cause fever, vomiting, and diarrhea in humans. Antibiotic treatment is suggested for patients with severe campylobacteriosis. However, the interpretative criteria for antibiotic susceptibility are inconsistent between Clinical and Laboratory Standards Institute and European Committee on Antimicrobial Susceptibility Testing guidelines. The aim of the study is to investigate the antibiotic susceptibility and prevalence of cytolethal distending toxin genes and to evaluate antibiotic susceptibility testing methods in the clinical laboratories of two tertiary medical centers in Taiwan. In total, 236 bacterial isolates were collected between 2001 and 2014. The disk diffusion and E-test methods were used to evaluate the antibiotic susceptibility, and broth dilution results were used as a reference. The virulence genes cdtA, cdtB, cdtC, and ceuE were detected through polymerase chain reaction. The antimicrobial sensitivity rates for erythromycin, ciprofloxacin, and tetracycline using the broth dilution assay were 80.4, 5.4, and 3.4%, respectively. No significant differences were observed in the antibiotic susceptibility of the isolates obtained from southern and northern Taiwan. However, some differences were observed between species. The susceptibility test for erythromycin (disk diffusion) showed that the isolates with small inhibition zone diameters were all resistant, and five isolates (4.0%) with large IZDs were non-sensitive. The error rate of the disk diffusion method according to the CLSI M45-A3 guideline was 5.4% (8/148). The incompatibility rates between the E-test and broth dilution methods for erythromycin, ciprofloxacin, and tetracycline were 8.0, 5.3, and 1.3%, respectively. The positive rates of the genes cdtA and cdtC were considerably higher in Campylobacter jejuni than in C. coli. Erythromycin is recommended as the first choice of treatment for campylobacteriosis. The disk diffusion method is suitable for prescreening Campylobacter susceptibility by using the CLSI M45-A2 and EUCAST criteria (low error rate of 3.4%). If antibiotic treatment fails or IZDs are between 6 and 20 mm, minimum inhibitory concentration testing by using the E-test method is highly recommended because the results of the E-test and broth dilution methods exhibit high agreement. The error rate of disk diffusion method using CLSI M45-A3 criteria is only slightly higher than B, which is also a suitable criteria.

Antifungal susceptibility of Candida species isolated from patients with candidemia in southern Taiwan, 2007-2012: impact of new antifungal breakpoints.

The Clinical and Laboratory Standard Institute (CLSI) revised the clinical breakpoints (CBPs) for the azoles and echinocandins against Candida species in 2012. We aimed to report the epidemiology of candidemia and antifungal susceptibility of Candida species and evaluate the impact of new CBPs on antifungal susceptibility in our region. All blood isolates of Candida species were obtained from 2007 to 2012. The minimum inhibitory concentrations of fluconazole, voriconazole, echinocandins and flucytosine against Candida isolates were determined by Sensititre YeastOne system. Differences in susceptibility rates between the CBPs of previous and revised versions of CLSI were examined. Of 709 Candida isolates, the fluconazole-susceptible rate was 96.5% in Candida albicans, 85.8% in Candida tropicalis and 92.1% in Candida parapsilosis by the revised CBPs. Compared with the susceptibility results by previous CBPs, the marked reductions in susceptibility of C. albicans, C. tropicalis and C. parapsilosis to fluconazole, that of C. tropicalis and C. parapsilosis to voriconazole, that of C. tropicalis and Candida glabrata to anidulafungin and that of C. tropicalis, C. glabrata and Candida krusei to caspofungin by revised CBPs were found. In conclusion, Candida albicans and C. parapsilosis remain highly susceptible to fluconazole. The non-susceptible rates of Candida species to azoles and echinocandins increase with interpretation by the revised CBPs.

Accurate detection of binary toxin producer from Clostridium difficile by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

Thirsty-six binary toxin producers were detected with 2 genotypes (cdtA(+) and cdtB(+)) among 265 Clostridium difficile isolates by multiplex PCR. The rate of accurate differentiation between these 2 genotypes was 100% by 6-peak cluster analysis of spectra generated by Bruker Biotyper matrix-assisted laser desorption ionization/time-of-flight mass spectrometry.