Whole-genome analysis to describe a human adenovirus D8 conjunctivitis outbreak in a tertiary hospital.

Conjunctivitis is a frequent ocular disorder caused by human adenoviruses (HAdVs). Only a few of the 45 HAdV-D species are associated with epidemic keratoconjunctivitis, including HAdV-D8. Nosocomial outbreaks due to HAdV-D8 have been rarely described, because keratoconjunctivitis cases are clinically diagnosed and treated without having to characterize the causative agent. Moreover, molecular typing is tedious when using classical techniques. In this study, a hospital outbreak of conjunctivitis caused by HAdV-D8 was characterized using the recently developed whole-genome sequencing (WGS) method. Of the 363 patients attending the Ophthalmology Department between July 13 and August 13, 2018, 36 may have acquired intrahospital conjunctivitis. Also, 11 of 22 samples sent to the Virology section were selected for WGS analysis. The WGS results revealed that 10 out of 11 HAdV-D8 strains were closely related. The remaining strain (Case 28) was more similar to a strain from an outbreak in Germany obtained from a public sequence database. WGS results showed that outbreak HAdV-D8 strains had a minimum percentage of identity of 94.3%. WGS is useful in a clinical setting, because it avoids carrying out viral culture or specific polymerase chain reaction sequencing. The public availability of sequence reads makes it easier to compare clusters in circulation. In conclusion, WGS can play an important role in standard routines to describe viral outbreaks.

Cross-transmission Is Not the Source of New Mycobacterium abscessus Infections in a Multicenter Cohort of Cystic Fibrosis Patients.

BACKGROUND: Mycobacterium abscessus is an extensively drug-resistant pathogen that causes pulmonary disease, particularly in cystic fibrosis (CF) patients. Identifying direct patient-to-patient transmission of M. abscessus is critically important in directing an infection control policy for the management of risk in CF patients. A variety of clinical labs have used molecular epidemiology to investigate transmission. However, there is still conflicting evidence as to how M. abscessus is acquired and whether cross-transmission occurs. Recently, labs have applied whole-genome sequencing (WGS) to investigate this further and, in this study, we investigated whether WGS can reliably identify cross-transmission in M. abscessus. METHODS: We retrospectively sequenced the whole genomes of 145 M. abscessus isolates from 62 patients, seen at 4 hospitals in 2 countries over 16 years. RESULTS: We have shown that a comparison of a fixed number of core single nucleotide variants alone cannot be used to infer cross-transmission in M. abscessus but does provide enough information to replace multiple existing molecular assays. We detected 1 episode of possible direct patient-to-patient transmission in a sibling pair. We found that patients acquired unique M. abscessus strains even after spending considerable time on the same wards with other M. abscessus-positive patients. CONCLUSIONS: This novel analysis has demonstrated that the majority of patients in this study have not acquired M. abscessus through direct patient-to-patient transmission or a common reservoir. Tracking transmission using WGS will only realize its full potential with proper environmental screening, as well as patient sampling.

Subthreshold transpupillary thermotherapy in management of foveal subretinal fluid in small pigmented choroidal lesions.

PURPOSE: To evaluate the effect of subthreshold transpupillary thermotherapy (sTTT) in foveal subretinal fluid of small pigmented choroidal lesions. METHODS: Retrospective, noncomparative, interventional case series. We reviewed patients with small pigmented choroidal lesions presenting foveal subretinal fluid and treated with sTTT to evaluate fluid regression. RESULTS: We treated 13 patients with small pigmented choroidal lesions with a mean height of 2.02 ± 0.54 mm (range, 1.4-2.9 mm) and a mean largest diameter of 7.60 ± 1.98 mm (range, 5-11 mm). In 11 cases, foveal subretinal fluid was completely resolved (84.6%), with a mean follow-up of 42.46 ± 26.29 months (range, 12-103 months). The mean number of sTTT sessions applied was 1.38 ± 0.77 (range, 1-3 sessions), at a mean spot size of 1,570.59 ± 795.1 µm (range, 500-3,000 µm), and overall exposure time of 2.32 ± 1.2 minutes (range, 1-6 minutes). Mean laser power applied was 370.63 ± 162.87 mW (range, 200 to 600 mW). Best-corrected visual acuity at the time of diagnosis was maintained or improved in 69.3% of patients after sTTT treatment. During follow-up, tumor progression was reported in 5 cases, regardless of the presence of subretinal fluid. These cases were treated promptly with brachytherapy. CONCLUSION: However, sTTT may be effective in solving foveal subretinal fluid in small pigmented choroidal lesions, attaining satisfactory visual acuity in most cases.

In Vitro Effect of Three-Antibiotic Combinations plus Potential Antibiofilm Agents against Biofilm-Producing Mycobacterium avium and Mycobacterium intracellulare Clinical Isolates.

Patients with chronic pulmonary diseases infected by Mycobacterium avium complex (MAC) often develop complications and suffer from treatment failure due to biofilm formation. There is a lack of correlation between in vitro susceptibility tests and the treatment of clinical isolates producing biofilm. We performed susceptibility tests of 10 different three-drug combinations, including two recommended in the guidelines, in biofilm forms of eight MAC clinical isolates. Biofilm developed in the eight isolates following incubation of the inoculum for 3 weeks. Then, the biofilm was treated with three-drug combinations with and without the addition of potential antibiofilm agents (PAAs). Biofilm bactericidal concentrations (BBCs) were determined using the Vizion lector system. All selected drug combinations showed synergistic activity, reducing BBC values compared to those treated with single drugs, but BBC values remained high enough to treat patients. However, with the addition of PAAs, the BBCs steadily decreased, achieving similar values to the combinations in planktonic forms and showing synergistic activity in all the combinations and in both species. In conclusion, three-drug combinations with PAAs showed synergistic activity in biofilm forms of MAC isolates. Our results suggest the need for clinical studies introducing PAAs combined with antibiotics for the treatment of patients with pulmonary diseases infected by MAC.

Activity of Antibiotics and Potential Antibiofilm Agents against Biofilm-Producing Mycobacterium avium-intracellulare Complex Causing Chronic Pulmonary Infections.

Nontuberculous mycobacteria (NTM) cause lung infections in patients with underlying pulmonary diseases (PD). The Mycobacteriumavium-intracellulare complex (MAC) is the most frequently involved NTM. The MAC-PD treatment is based on the administration of several antibiotics for long periods of time. Nonetheless, treatment outcomes remain very poor. Among the factors involved is the ability of MAC isolates to form biofilm. The aim of the study was to assess the in vitro activity of different antibiotics and potential antibiofilm agents (PAAs) against MAC biofilm. Four antibiotics and six PAAs, alone and/or in combination, were tested against planktonic forms of 11 MAC clinical isolates. Biofilm was produced after 4 weeks of incubation and analyzed with the crystal violet assay. The antibiotics and PAAs were tested by measuring the absorbance (minimum biofilm inhibition concentrations, MBICs) and by performing subcultures (minimum biofilm eradication concentrations, MBECs). The clarithromycin/amikacin and clarithromycin/ethambutol combinations were synergistic, decreasing the MBECs values compared to the individual antibiotics. The amikacin/moxifloxacin combination showed indifference. The MBIC values decreased significantly when PAAs were added to the antibiotic combinations. These results suggest that antibiotic combinations should be further studied to establish their antibiofilm activity. Moreover, PAAs could act against the biofilm matrix, facilitating the activity of antibiotics.

Taxonomic Identification of Different Species of the Genus Aeromonas by Whole-Genome Sequencing and Use of Their Species-Specific ß-Lactamases as Phylogenetic Markers.

Some Aeromonas species, potentially pathogenic for humans, are known to express up to three different classes of chromosomal ß-lactamases, which may become hyperproduced and cause treatment failure. The aim of this study was to assess the utility of these species-specific ß-lactamase genes as phylogenetic markers using whole-genome sequencing data. Core-genome alignments were generated for 36 Aeromonas genomes from seven different species and scanned for antimicrobial resistance genes. Core-genome alignment confirmed the MALDI-TOF identification of most of the isolates and re-identified an A. hydrophila isolate as A. dhakensis. Three (B, C and D) of the four Ambler classes of ß-lactamase genes were found in A. sobria, A. allosacharophila, A. hydrophila and A. dhakensis (blaCphA, blaAmpC and blaOXA). A. veronii only showed class-B- and class-D-like matches (blaCphA and blaOXA), whereas those for A. media, A. rivipollensis and A. caviae were class C and D (blaCMY, blaMOX and blaOXA427). The phylogenetic tree derived from concatenated sequences of ß-lactamase genes successfully clustered each species. Some isolates also had resistance to sulfonamides, quinolones and aminoglycosides. Whole-genome sequencing proved to be a useful method to identify Aeromonas at the species level, which led to the unexpected identification of A. dhakensis and A.rivipollensis and revealed the resistome of each isolate.

Tumor Volumes in Choroidal Melanoma: Agreement Between Three-Dimensional Ultrasound and Two Mathematical Models.

PURPOSE: To determine the degree of agreement between 2 mathematical models and 3-dimensional ultrasonography (3DUS) in estimating choroidal melanoma tumor volumes. DESIGN: Reliability analysis. METHODS: Tumor measurements estimated by 2 mathematical models (designated Formula 1 and Formula 2) were compared to those obtained by 3DUS in 45 consecutive patients with primary choroidal melanoma to determine the percentage agreement between the models and 3DUS. RESULTS: Both formulas tended to overestimate the tumor volume. Overall, the mean volume differences between 3DUS and Formula 1 and between 3DUS and Formula 2, respectively, were 51.7 mm(3) (95% confidence interval [CI], 187.6 to 84.3) and 23.8 mm(3) (95% CI, 122.5 to 74.8). Excluding mushroom-shaped tumors, the mean volume differences were 52.0 mm(3) (95% CI, 194.9 to 91.0) and 23.0 mm(3) (95% CI, 127.0 to 81.0), respectively. In mushroom-shaped tumors, mean volume differences were 49.9 mm(3) (95% CI, 135.7 to 35.9) and 29.3 mm(3) (95% CI, 87.6 to 29.0), respectively. CONCLUSIONS: The agreement between these mathematical models and the measured 3DUS volume was high. The data obtained in this study show that both formulas provide a simple, fast, and accurate method of estimating tumor volumes in the clinical setting, suggesting that these models could be used as a reliable and inexpensive alternative to time-consuming procedures such as 3DUS or magnetic resonance imaging. The accurate tumor volume values provided by these formulas may help to provide more reliable estimates of tumor regression or regrowth following globe-preserving treatment of choroidal melanomas, and may be a valuable prognostic indicator.

Inducible and Acquired Clarithromycin Resistance in the Mycobacterium abscessus Complex.

PURPOSE: Clarithromycin was considered the cornerstone for the treatment of Mycobacterium abscessus complex infections. Genetic resistance mechanisms have been described and many experts propose amikacin as an alternative. Nevertheless, clarithromycin has several advantages; therefore, it is necessary to identify the non-functional erm(41) allele to determine the most suitable treatment. The aims of this study were to characterize the molecular mechanisms of clarithromycin resistance in a collection of Mycobacterium abscessus complex isolates and to verify the relationship between these mechanisms and the antibiogram. MATERIALS AND METHODS: Clinical isolates of M. abscessus complex (n = 22) from 16 patients were identified using four housekeeping genes (rpoB, secA1, sodA and hsp65), and their genetic resistance was characterized by studying erm(41) and rrl genes. Nine strains were recovered from the clinical isolates and subjected to E-test and microdilution clarithromycin susceptibility tests, with readings at 3, 7 and 14 days. RESULTS: We classified 11/16 (68.8%) M. abscessus subsp. abscessus, 4/16 (25.0%) M. abscessus subsp. bolletii, and 1/16 (6.3%) M. abscessus subsp. massiliense. T28 erm(41) allele was observed in 8 Mycobacterium abscessus subps. abscessus and 3 Mycobacterium abscessus subsp. bolletii. One strain of M. abscessus subsp. bolletii had an erm(41) gene truncated and was susceptible to clarithromycin. No mutations were observed in rrl gene first isolates. In three patients, follow-up of initial rrl wild-type strains showed acquired resistance. CONCLUSIONS: Most clinical isolates of M. abscessus complex had inducible resistance to clarithromycin and total absence of constitutive resistance. Our findings showed that the acquisition of resistance mutations in rrl gene was associated with functional and non-functional erm(41) gene. Caution is needed when using erm(41) sequencing alone to identify M. abscessus subspecies. This study reports an acquired mutation at position 2057 of rrl gene, conferring medium-low clarithromycin constitutive resistance.

Corneal edema and intraocular pressure after cataract surgery: randomized comparison of Healon5 and Amvisc Plus.

PURPOSE: To compare the protective effect of Healon5 (sodium hyaluronate 2.3%) and Amvisc Plus (sodium hyaluronate 1.6%) against corneal edema and their association with postoperative intraocular pressure (IOP) spikes in patients having phacoemulsification and intraocular lens (IOL) implantation. SETTING: Ophthalmology department of a general hospital. METHODS: One hundred forty patients were randomly assigned to have surgery with Healon5 (n = 70) or Amvisc Plus (n = 70). One eye of each patient was analyzed. Data collected preoperatively included best corrected visual acuity (BCVA) and IOP. Central ultrasonic pachymetry was performed in all patients. The same ophthalmologist performed all surgeries. The IOP and central corneal thickness (CCT) were measured 1 and 4 days and 1 month after surgery. The BCVA was also assessed at 1 month. RESULTS: There were no significant preoperative differences between the Healon5 and Amvisc Plus groups in sex, age, ocular pathology, BCVA, IOP, or CCT. Intraoperative variables were similar between groups, but it took significantly longer to remove the Healon5. Postoperatively, there were no differences between groups in the evolution of CCT or of IOP. Intraocular pressure spikes over 30 mm Hg were detected at 1 day in 7 patients in the Healon5 group and 2 patients in the Amvisc Plus group (10.0% versus 2.9%; P = .165). CONCLUSIONS: Both OVDs were beneficial in a wide range of cataract patients. However, the results suggest a tendency toward a higher complication rate with Healon5.

Endoresection versus iodine-125 plaque brachytherapy for the treatment of choroidal melanoma.

PURPOSE: To compare the effectiveness of pars plana vitrectomy endoresection with iodine-125 brachytherapy in the treatment of choroidal melanoma. DESIGN: A nested case-control study (1:2) from a surgical cohort. METHODS: The study comprised 81 choroidal melanoma patients treated with either endoresection or iodine-125 brachytherapy. Twenty-seven patients who had undergone endoresection were matched according to tumor height and postequatorial tumor location with 54 cases treated with iodine-125 brachytherapy. Metastatic disease, overall survival, local tumor recurrence, visual acuity, and secondary enucleation rates were analyzed and compared between groups. RESULTS: Metastatic spread was observed in 11 patients in the iodine-125 brachytherapy group vs only 1 patient in the endoresection group (20.4% and 3.7%, respectively, P = .053). Fourteen patients died during follow-up: 11 in the brachytherapy arm vs 3 in the endoresection arm (20.4% and 11.1%, respectively, P = .238). For the iodine-125 brachytherapy and endoresection groups, respectively, the 5-year Kaplan-Meier estimates were as follows: overall survival, 81.5% vs 89.2% (log-rank test, P = .429;); relapse-free survival, 96.6% vs 92.4% (P = .2); visual acuity retention equal or superior to 20/200, 66.4% vs 59.9% (P = .083), and eye retention, 85.7% vs 87.8% (P = .942). CONCLUSIONS: Endoresection for choroidal melanoma is an effective treatment modality in selected cases of posterior choroidal melanomas, with outcomes similar to those obtained with iodine-125 brachytherapy.

Acute onset of retinal detachment after posterior chamber phakic intraocular lens implantation.

CASE REPORT: A 34-year-old man with severe myopia, presented with acute visual loss in his right eye. This occurred 3 hours after a posterior chamber phakic (PCP) intraocular lens (IOL) implantation, and was associated with a rhegmatogenous retinal detachment. Retinal retachment surgery was performed without complications, with the outcome showing good anatomical and functional results during a 2-year follow-up period. DISCUSSION: Despite the fact that several authors have described retinal detachments following PCP IOL implantation in highly myopic patients, there is no evidence that this procedure increases the risk of retinal detachment in these patients. The occurrence of the retinal detachment immediately after the phakic IOL implantation supports the hypothesis that the surgical procedure could induce iatrogenic changes in patients with high myopia, which could increase the incidence of retinal detachment. In contrast to other reports, the interval between the PCP IOL implantation and the retinal detachment was only 3 hours in our patient. We believe this demonstrates the importance of performing a complete preoperative vitreoretinal examination in patients with severe myopia.