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Parasitology Research Aug 2021Acanthamoeba spp. have always caused disease in immunosuppressed patients, but since 1986, they have become a worldwide public health issue by causing infection in... (Review)
Review
Acanthamoeba spp. have always caused disease in immunosuppressed patients, but since 1986, they have become a worldwide public health issue by causing infection in healthy contact lens wearers. Amoebae of the Acanthamoeba genus are broadly distributed in nature, living either freely or as parasites, and are frequently associated with biofilms throughout the environment. These biofilms provide the parasite with protection against external aggression, thus favoring its increased pathogeny. This review aims to assess observational studies on the association between Acanthamoeba spp. and biofilms, opening potential lines of research on this severe ocular infection. A systematic literature search was conducted in May 2020 in the following databases: PubMed Central/Medline, LILACS, The Cochrane Library, and EMBASE. The studies were selected following the inclusion and exclusion criteria specifically defined for this review. Electronic research recovered 353 publications in the literature. However, none of the studies met the inclusion criterion of biofilm-producing Acanthamoeba spp., inferring that the parasite does not produce biofilms. Nonetheless, 78 studies were classified as potentially included regarding any association of Acanthamoeba spp. and biofilms. These studies were allocated across six different locations (hospital, aquatic, ophthalmic and dental environments, biofilms produced by bacteria, and other places). Acanthamoeba species use biofilms produced by other microorganisms for their benefit, in addition to them providing protection to and facilitating the dissemination of pathogens residing in them.
Topics: Acanthamoeba; Bacteria; Biofilms; Contact Lenses; Hospitals; Humans; Observational Studies as Topic
PubMed: 34292376
DOI: 10.1007/s00436-021-07240-6 -
Parasitology Research Sep 2021Acanthamoeba spp. are among the most worldwide prevalent protozoa. It is the causative agent of a disease known as Acanthamoeba keratitis, a painful and severe... (Review)
Review
Acanthamoeba spp. are among the most worldwide prevalent protozoa. It is the causative agent of a disease known as Acanthamoeba keratitis, a painful and severe sight-threatening corneal infection that can lead to blindness. In recent years, the prevalence of Acanthamoeba keratitis has rapidly increased, growing its importance to human health. This systematic review aims to assess the distribution of Acanthamoeba sp. genotypes causing keratitis around the world, considering the sample collected type and the used identification method. Most of the cases were found in Asia and Europe. Not surprisingly, the T4 genotype was the most prevalent worldwide, followed by T3, T15, T11, and T5. Furthermore, the T4 genotype contains a higher number of species. Given the differences in pathology, susceptibility to treatment, and clinical outcome between distinct genotypes, it is essential to genotype isolates from Acanthamoeba keratitis cases to help to establish a better correlation between in vitro and in vivo activities, resulting in better drug therapies and successful treatment in cases of this important ocular infection.
Topics: Acanthamoeba; Acanthamoeba Keratitis; Cornea; Genotype; Humans
PubMed: 34351492
DOI: 10.1007/s00436-021-07261-1 -
The Cochrane Database of Systematic... Feb 2015Acanthamoeba are microscopic, free-living, single-celled organisms which can infect the eye and lead to Acanthamoeba keratitis (AK). AK can result in loss of vision in... (Review)
Review
BACKGROUND
Acanthamoeba are microscopic, free-living, single-celled organisms which can infect the eye and lead to Acanthamoeba keratitis (AK). AK can result in loss of vision in the infected eye or loss of eye itself; however, there are no formal guidelines or standards of care for the treatment of AK.
OBJECTIVES
To evaluate the relative effectiveness and safety of medical therapy for the treatment of AK.
SEARCH METHODS
We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2015, Issue 1), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to January 2015), EMBASE (January 1980 to January 2015), PubMed (1948 to January 2015), Latin American and Caribbean Health Sciences Literature Database (LILACS) (1982 to January 2015), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic search for trials. We last searched the electronic databases on 9 January 2015.
SELECTION CRITERIA
We included randomized controlled trials (RCTs) of medical therapy for AK, regardless of the participants' age, sex, or etiology of disease. We included studies that compared either anti-amoeba therapy (drugs used alone or in combination with other medical therapies) with no anti-amoeba therapy or one anti-amoeba therapy with another anti-amoeba therapy.
DATA COLLECTION AND ANALYSIS
Two authors independently screened search results and full-text reports, assessed risk of bias, and abstracted data. We used standard methodological procedures as set forth by the Cochrane Collaboration.
MAIN RESULTS
We included one RCT (56 eyes of 55 participants) in this review. The study compared two types of topical biguanides for the treatment of AK: chlorhexidine 0.02% and polyhexamethylene biguanide (PHMB) 0.02%. All participants were contact lens wearers with a median age of 31 years. Treatment duration ranged from 51 to 145 days. The study, conducted in the UK, was well-designed and had low risk of bias overall.Outcome data were available for 51 (91%) of 56 eyes. Follow-up times for outcome measurements in the study were not reported. Resolution of infection, defined as control of ocular inflammation, relief of pain and photosensitivity, and recovery of vision, was 86% in the chlorhexidine group compared with 78% in the PHMB group (relative risk (RR) 1.10, 95% confidence intervals (CI) 0.84 to 1.42). In the chlorhexidine group, 20 of 28 eyes (71%) had better visual acuity compared with 13 of 23 eyes (57%) in the PHMB group at final follow-up (RR 1.26, 95% CI 0.82 to 1.94). Five participants required therapeutic keratoplasty: 2 in the chlorhexidine group compared with 3 in the PHMB group (RR 0.55, 95% CI 0.10 to 3.00). No serious adverse event related to drug toxicity was observed in the study.
AUTHORS' CONCLUSIONS
There is insufficient evidence to evaluate the relative effectiveness and safety of medical therapy for the treatment of AK. Results from the one included study yielded no difference with respect to outcomes reported between chlorhexidine and PHMB. However, the sample size was inadequate to detect clinically meaningful differences between the two groups as indicated by the wide confidence intervals of effect estimates.
Topics: Acanthamoeba Keratitis; Anti-Infective Agents, Local; Biguanides; Chlorhexidine; Humans; Randomized Controlled Trials as Topic
PubMed: 25710134
DOI: 10.1002/14651858.CD010792.pub2 -
Pathogens (Basel, Switzerland) Feb 2021, an opportunistic pathogen is known to cause an infection of the cornea, central nervous system, and skin. feeds different microorganisms, including potentially... (Review)
Review
, an opportunistic pathogen is known to cause an infection of the cornea, central nervous system, and skin. feeds different microorganisms, including potentially pathogenic prokaryotes; some of microbes have developed ways of surviving intracellularly and this may mean that acts as incubator of important pathogens. A systematic review of the literature was performed in order to capture a comprehensive picture of the variety of microbial species identified within following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Forty-three studies met the inclusion criteria, 26 studies (60.5%) examined environmental samples, eight (18.6%) studies examined clinical specimens, and another nine (20.9%) studies analysed both types of samples. Polymerase chain reaction (PCR) followed by gene sequencing was the most common technique used to identify the intracellular microorganisms. Important pathogenic bacteria, such as , spp. and were observed in clinical isolates of , whereas , adenovirus, mimivirus, and unidentified bacteria () were often identified in environmental . Increasing resistance of associated intracellular pathogens to antimicrobials is an increased risk to public health. Molecular-based future studies are needed in order to assess the microbiome residing in , as a research on the hypotheses that intracellular microbes can affect the pathogenicity of infections.
PubMed: 33670718
DOI: 10.3390/pathogens10020225 -
Graefe's Archive For Clinical and... Sep 2023The success of corneal collagen cross-linking in altering keratoconus' clinical course has driven a search for further uses of this procedure. This literature review...
PURPOSE
The success of corneal collagen cross-linking in altering keratoconus' clinical course has driven a search for further uses of this procedure. This literature review aims to analyze the scientific evidence available for the benefit of cross-linking in the management of ophthalmic diseases other than progressive keratoconus or ectasia induced by corneal refractive procedures.
METHODS
A systemic literature review.
RESULTS
We reviewed 97 studies. We found that collagen cross-linking can limit the progression of several other corneal ectasias, thus reducing and limiting the need for keratoplasty. Collagen cross-linking also can reduce the refractive power of the cornea and can be considered for a moderate degree of bacterial keratitis or when the organism is unidentified, which is refractive to antibiotics alone. However, the comparative rarity of these procedures has limited the extent of evidence. In fungal, Acanthamoeba, and herpes virus keratitis, the evidence is inconclusive of the safety and efficacy of cross-linking.
CONCLUSION
Current clinical data is limited, and laboratory data has not fully correlated with published clinical data.
Topics: Humans; Collagen; Corneal Cross-Linking; Cross-Linking Reagents; Keratitis, Herpetic; Keratoconus; Photochemotherapy; Photosensitizing Agents; Riboflavin; Ultraviolet Rays
PubMed: 36881260
DOI: 10.1007/s00417-023-05994-6 -
Parasitology Research Nov 2022Free-living amoebae (FLA) are cosmopolitan microorganisms known to be pathogenic to humans who often have a history of contact with contaminated water. Swimming pools... (Meta-Analysis)
Meta-Analysis Review
Free-living amoebae (FLA) are cosmopolitan microorganisms known to be pathogenic to humans who often have a history of contact with contaminated water. Swimming pools and recreational waters are among the environments where the greatest human exposure to FLA occurs. This study aimed to determine the prevalence of FLA in swimming pools and recreational waters, through a systematic review and meta-analysis that included studies published between 1977 and 2022. A total of 106 studies were included and an overall prevalence of FLA in swimming pools and recreational waters of 44.34% (95% CI = 38.57-50.18) was found. Considering the studies published up to 2010 (1977-2010), between 2010 and 2015, and those published after 2010 (> 2010-2022), the prevalence was 53.09% (95% CI = 43.33-62.73) and 37.07% (95% CI = 28.87-45.66) and 45.40% (95% CI = 35.48-55.51), respectively. The highest prevalence was found in the American continent (63.99%), in Mexico (98.35%), and in indoor hot swimming pools (52.27%). The prevalence varied with the variation of FLA detection methods, morphology (57.21%), PCR (25.78%), and simultaneously morphology and PCR (43.16%). The global prevalence by genera was Vahlkampfia spp. (54.20%), Acanthamoeba spp. (33.47%), Naegleria spp. (30.95%), Hartmannella spp./Vermamoeba spp. (20.73%), Stenamoeba spp. (12.05%), and Vannella spp. (10.75%). There is considerable risk of FLA infection in swimming pools and recreational waters. Recreational water safety needs to be routinely monitored and, in case of risk, locations need to be identified with warning signs and users need to be educated. Swimming pools and artificial recreational water should be properly disinfected. Photolysis of NaOCl or NaCl in water by UV-C radiation is a promising alternative to disinfect swimming pools and artificial recreational waters.
Topics: Amoeba; Humans; Prevalence; Sodium Chloride; Swimming Pools; Water
PubMed: 36040629
DOI: 10.1007/s00436-022-07631-3 -
Annals of Parasitology 2018Acanthamoeba, an opportunistic protozoan parasite, is distributed in the environment globally, causes serious human infections, including a fatal encephalitis and... (Meta-Analysis)
Meta-Analysis
Acanthamoeba, an opportunistic protozoan parasite, is distributed in the environment globally, causes serious human infections, including a fatal encephalitis and keratitis. The purpose of this study was to evaluate the prevalence and genotyping of Acanthamoeba spp. from different water and soil sources in Iran. Six English language and four Persian language databases were searched to identify studies published from March 2005 to October 2016. Random effect model and Stats Direct statistical software was used for the meta-analysis. This review resulted in a total 34 articles meeting the including criteria. The overall prevalence rate of Acanthamoeba spp. among the 1850 water and soil samples in Iran with using random-effect model was estimated 42.7%. The genotyping results of the Acanthamoeba isolates showed that T4 (81.2%) was a predominant strain in Iran. In addition, other genotypes, T2, T3, T4, T5, T6, T11, T13, T15, mixed T3/T4 and mixed T2/T6, were obtained in the environmental samples of Iran. This study may be the first systematic review and meta-analysis of Acanthamoeba prevalence and genotyping in different environmental sources of Iran. Knowledge about wide distribution of Acanthamoeba T4 in the environmental sources may help physicians to manage the patients and susceptible persons in Iran.
Topics: Acanthamoeba; Acanthamoeba Keratitis; Genotype; Humans; Iran; Soil; Water
PubMed: 30710471
DOI: 10.17420/ap6404.163 -
International Ophthalmology Aug 2023Acanthamoeba keratitis (AK) and fungal keratitis (FK) are two microbial keratitis that cause serious damage and, without early accurate diagnosis and treatment, may lead... (Meta-Analysis)
Meta-Analysis Review
PURPOSE
Acanthamoeba keratitis (AK) and fungal keratitis (FK) are two microbial keratitis that cause serious damage and, without early accurate diagnosis and treatment, may lead to blindness. In vivo corneal confocal scan, as an emerging ocular diagnostic method in comparison with microbiological smears and cultures as the gold standard, may assist in accelerating appropriate diagnosis.
OBJECTIVE
To determine the diagnostic accuracy of confocal scan for the diagnosis of AK and FK.
METHODS
Data were collected via a comprehensive literature search of PubMed, Web of Science, Cochrane Library, Embase and Scopus using keywords related to diagnostic accuracy of confocal scan in AK and FK up to October 2022. Pooled data underwent meta-analysis in terms of sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall diagnostic odds ratio (DOR) of confocal scan for the diagnosis of AK and FK.
RESULTS
The final 14 relevant studies were identified, including 1950 eyes. Meta-analysis in AK group revealed 94% sensitivity, 87% specificity, 89% PPV, 92% NPV, and DOR of 143.32, and in FK group disclosed 88% sensitivity, 85% specificity, 85% PPV, 88% NPV, and DOR of 75.98.
CONCLUSION
The accuracy of confocal scan for the diagnosis of AK was significantly more than that for detecting FK; despite the limitations such as limited numbers of available retrospective studies for the detection of FK, confocal scan had an acceptable performance in detecting FK eyes. The overall performance of NCS was similar with that of HRT-RCM for the detection of both types of keratitis.
Topics: Humans; Acanthamoeba Keratitis; Retrospective Studies; Microscopy, Confocal; Corneal Ulcer; Cornea; Eye Infections, Fungal
PubMed: 36977847
DOI: 10.1007/s10792-023-02689-z -
Expert Review of Anti-infective Therapy Nov 2021: encompasses several species of free-living ameba encountered commonly throughout the environment. Unfortunately, these species of ameba can cause opportunistic...
: encompasses several species of free-living ameba encountered commonly throughout the environment. Unfortunately, these species of ameba can cause opportunistic infections that result in keratitis, granulomatous amebic encephalitis, and occasionally systemic infection.: This review discusses relevant literature found through PubMed and Google scholar published as of January 2021. The review summarizes current common keratitis treatments, drug discovery methodologies available for screening potential anti- compounds, and the anti- activity of various azole antifungal agents.: While several biguanide and diamidine antimicrobial agents are available to clinicians to effectively treat keratitis, no singular treatment can effectively treat every keratitis case.Efforts to identify new anti-Acanthamoeba agents include trophozoite cell viability assays, which are amenable to high-throughput screening. Cysticidal assays remain largely manual and would benefit from further automation development. Additionally, the existing literature on the effectiveness of various azole antifungal agents for treating keratitis is incomplete or contradictory, suggesting the need for a systematic review of all azoles against different pathogenic strains.
Topics: Acanthamoeba; Acanthamoeba Keratitis; Amebicides; Azoles; Drug Evaluation, Preclinical; Humans
PubMed: 33929276
DOI: 10.1080/14787210.2021.1924673 -
Infection Dec 2017Myopia is a prevalent condition among Asians. Orthokeratology lens has gained popularity as a method of myopia control. This systematic review is to summarize the... (Review)
Review
PURPOSE
Myopia is a prevalent condition among Asians. Orthokeratology lens has gained popularity as a method of myopia control. This systematic review is to summarize the clinical profile of infectious keratitis in association with orthokeratology lens wear.
METHODS
We searched in the PubMed and EMBASE for articles adopting the search strategy "(orthokeratology lens OR orthokeratology) AND (bacterial eye infection OR keratitis OR cornea ulcer OR microbial keratitis OR bacterial keratitis)", from the start date of the databases to August 23, 2016. Articles reporting infectious keratitis in orthokeratology lens users with data of individual cases were considered eligible for this systematic review. We recorded the outcome measures including method of diagnosis, etiological agents, duration and mode of treatment and treatment outcomes.
RESULTS
Our literature search yielded 172 papers. After removing duplicated and irrelevant reports, we included 29 articles for data analysis, involving 173 eyes. Among all reported cases, the mean age at presentation was 15.4 ± 6.2 years, with a female preponderance (male-to-female ratio 1:1.7). Positive microbiological cultures were reported in 69.4% of cases, with Pseudomonas aeruginosa and Acanthamoeba being the most common etiological agents. The mean duration of hospitalization was 7.7 ± 6.7 days. Mean LogMAR visual acuity at presentation was 1.17 ± 0.78, increased to 0.33 ± 0.41 at final visit (p < 0.001).
CONCLUSIONS
Despite early intervention and treatment, the majority of infections resulted in the formation of corneal scars and almost 10% of eyes needed surgical treatment. Timely awareness and treatment of keratitis should be emphasized to the users.
Topics: Corneal Ulcer; Eye Infections, Bacterial; Humans; Keratitis; Orthokeratologic Procedures
PubMed: 28534320
DOI: 10.1007/s15010-017-1023-2