Comparison of clinical characteristics and antibiotic susceptibility between Pseudomonas aeruginosa and P. putida keratitis at a tertiary referral center: a retrospective study

Optimizing Systems for Robust Heterologous Production of Biosurfactants Rhamnolipid and Lyso-Ornithine Lipid in Pseudomonas putida KT2440

Surfactants are amphiphilic molecules that are capable of mixing water and oil. Biosurfactants are eco-friendly, low-toxicity, and stable to a variety of environmental factors. Optimizing conditions for microorganisms to produce biosurfactants can lead to improved production suitable for scaling up. In this study, we compared heterologous expression levels of the luminescence system luxCDABE operon controlled by regulatable promoters araC-PBAD and its strong version araC-PBAD-SD in Escherichia coli K12, Pseudomonas aeruginosa PAO1, and P. putida KT2440. Real-time monitoring of luminescence levels in the three strains indicated that luxCDABE controlled by araC-PBAD-SD promoter with 0.2% arabinose supplementation in P. putida produced the highest level of luminescence. By using the araC-PBAD-SD promoter-controlled rhlAB expression in P. putida, we were able to produce mono-rhamnolipid at a level of 1.5 g L-1 when 0.02% arabinose was supplemented. With the same system to express olsB, lyso-ornithine lipid was produced at a level of 10 mg L-1 when 0.2% arabinose was supplemented. To our knowledge, this is the first report about optimizing conditions for lyso-ornithine lipid production at a level up to 10 mg L-1. Taken together, our results demonstrate that regulatable araC-PBAD-SD promoter in P. putida KT2440 is a useful system for heterologous production of biosurfactants.

Ocular microbiome changes in dry eye disease and meibomian gland dysfunction

The most common and chronic ocular problem of aging is dry eye disease (DED) and the associated condition of meibomian gland dysfunction (MGD). The resident ocular surface bacteria may have a role in maintaining homeostasis and perturbation may contribute to disease development. The aim of this study was to compare the microbiomes of the conjunctiva and eyelid margin in humans with mild and moderate DED and controls using 16 S rRNA gene sequencing. The conjunctiva and lid margin of three cohorts (N = 60; MGD, MGD with lacrimal dysfunction [MGD + LD] and controls) were swabbed bilaterally three times over three months. Microbial communities were analysed by extracting DNA and sequencing the V3-V4 region of the 16 S ribosomal RNA gene using the Illumina MiSeq platform. Sequences were quality filtered, clustered into amplicon sequence variants (ASVs) using UNOISE algorithm and taxonomically classified using a Bayesian Last Common Ancestor (BCLA) algorithm against the GTDB 2207 database. The overall microbial communities of the MGD, MGD + LD and control groups were significantly different from each other (P = 0.001). The MGD and MGD + LD dry eye groups showed greater variability between individuals compared to the control (PERMDISP, P < 0.01). There was decreased richness and diversity in females compared to males for the conjunctiva (P < 0.04) and eyelid margin (P < 0.018). The conjunctiva in the MGD + LD group had more abundant Pseudomonas azotoformans, P. oleovorans and Caballeronia zhejiangensis compared to MGD and control (P < 0.05), while the MGD group had more abundant Corynebacterium macginleyi and C. kroppenstedtii compared to control (P < 0.05). The lid margin in MGD was more abundant in C. macginleyi, C. accolens, and C. simulans compared to the MGD + LD and control (P < 0.05). There were differences in the overall microbial community composition and certain taxa, including increased levels of lipophilic bacteria, on the conjunctiva and eyelid margin in mild to moderate DED/MGD compared to controls. DED/MGD was also associated with a reduced bacterial richness and diversity in females.

Incidence, Clinical Profile, and Management of Keratitis Caused by Uncommon Species of Pseudomonas at a Tertiary Eye Care Center

PURPOSE

The purpose of this study was to study the incidence, demographic features, clinical course, profiling, and management of uncommon species of Pseudomonas keratitis (other than Pseudomonas aeruginosa ) at a tertiary eye care center.

METHODS

Thirty cases of culture-proven uncommon species of Pseudomonas keratitis between January 2017 and December 2021 were retrospectively studied. The incidence, demographic and clinical profile, predisposing factors, microbial results, treatment, and visual outcomes were analyzed. We evaluated the risk factors for poor treatment outcomes.

RESULTS

Among bacterial keratitis cases, uncommon species of Pseudomonas keratitis occurred at a rate of 2.2%. The mean age at presentation was 51.37 years, and the most common predisposing factor was corneal trauma (36.7%). The mean best corrected visual acuity (BCVA) [in log of minimum angle of resolution (logMAR)] at presentation was 1.99, and the mean ulcer size was 5.75 mm. On culture, 56.7% of the cases were identified as Pseudomonas putida , 26.7% as Pseudomonas stutzeri , 10% as Pseudomonas mendocina, and 3.3% each of Pseudomonas oryzihabitans and Pseudomonas alcaligenes . We recorded good treatment responses in 66.7% of cases with the medical therapy of a combination of broad-spectrum antibiotics, whereas 33.3% of cases required surgical intervention. The risk factors for poor clinical outcome were older age, ocular trauma, previous ocular surgeries, poor BCVA at presentation, large ulcer size, delayed treatment, hypopyon, and early complications such as perforation, limbal involvement, and total ulcer.

CONCLUSIONS

Uncommon species of pseudomonas keratitis was more closely related to predisposing factors such as corneal trauma and other factors such as previous ocular surgeries, older age, large ulcers, longer duration of treatment, early surgical intervention in complicated cases, and poor visual outcome.

Clinical features, risk factors, and antimicrobial resistance of pseudomonas putida isolates

Pseudomonas putida rarely results in infection, primarily in patients undergoing invasive procedures or immunocompromised hosts. We aimed to investigate the characteristics of Pseudomonas putida infections. This is a retrospectively designed cross-sectional observational study. We retrospectively scanned the data from our hospital for the 10 years before February 15, 2022. The patients with Pseudomonas putida growth in the microbiological cultures and with antibiotic susceptibility tests were included in the study. We recorded culture isolates types, age, gender, comorbidities, immunosuppressive factors, symptoms, invasive medical procedures, length of hospital stay, and radiological findings. The mean age of the patients was 66.2 ± 14.5 years, and the male patients predominated (76.3%, n = 58/76). There was growth in bronchial lavage in 33 patients, sputum in 28, pleural effusion fluid in 12, and tracheal aspirate in 3 patients. The rate of antibiotic-resistant strains was 56.6% (n = 43). All strains were sensitive to colistin (100%), and carbapenem, amikacin, and gentamicin sensitivity rates were high. We observed that the risk of antibiotic resistance increased 4.29 times in the patients in the intensive care unit (Cl:1.27-14.47, P = .01). The patients with Diabetes Mellitus had a higher risk (OR 4.33, Cl:1.11-16.77, P = .03), and in cancer cases, the risk was 3.31 times higher (Cl:1.06-10.32, P = .03). The risk of Pseudomonas putida infection should be considered, particularly in patients with comorbid disorders causing immunosuppression, including Diabetes Mellitus and Cancer.

Clinical characteristics of external bacterial ocular and periocular infections and their antimicrobial treatment patterns among a Ghanaian ophthalmic population

Empirical antimicrobial therapy is linked to a surge in antimicrobial resistant infections. However, an insight on the bacteria etiology of ocular infections is essential in the appropriation of choice of antimicrobial among clinicians, yet there remains a dearth of data from Ghana. We investigated the bacteria etiology of external ocular and periocular infections and antimicrobial treatment patterns among a Ghanaian ophthalmic population. A multicenter study design with purposive sampling approach was employed. Patients demographics and clinical data were collated using a pretested structure questionnaire. Cornea specimens and conjunctival swabs were obtained for bacterial isolation following standard protocols. About 95% (98/103) of ocular samples were positive for bacteria culture. The proportion of Gram-negative bacteria was 58.2%, and the predominant bacteria species were Pseudomonas aeruginosa 38.8% and Staphylococcus aureus 27.6%. Conjunctivitis 40.0% and keratitis 75.0% were mostly caused by Pseudomonas aeruginosa. The routinely administered antimicrobial therapy were polymyxin B 41.2%, neomycin 35.1% and ciprofloxacin 31.6%. Participants demographic and clinical characteristics were unrelated with positive bacteria culture (p > 0.05). Our results showed a markedly high burden of ocular bacterial infections and variations in etiology. Bacterial infection-control and antimicrobial agent management programs should be urgently institutionalized to prevent the emergence of resistant infections.

Wedelolactone ameliorates Pseudomonas aeruginosa-induced inflammation and corneal injury by suppressing caspase-4/5/11/GSDMD-mediated non-canonical pyroptosis

Pseudomonas aeruginosa (P. aeruginosa) keratitis, a worldwide leading cause of corneal perforation and blindness, which is associated with contact lens usage. Increasing evidence has indicated that pyroptosis, a novel proinflammatory programmed cell death, is linked with ocular diseases, little is known about the role of noncanonical pyroptosis in microbial keratitis. Here, we first indicated the involvement of noncanonical pyroptosis in P. aeruginosa keratitis and investigated whether wedelolactone (WDL), a major active component of Eclipta prostrate known to target caspase-11, could alleviate P. aeruginosa keratitis development. We found the expression of caspase-4/5/11 and cleaved GSDMD in corneas of P. aeruginosa keratitis patients, animal models and lipopolysaccharide (LPS)-induced primary cultured human corneal keratocytes (piHCKs) were increased. Combining ciprofloxacin with WDL significantly ameliorated the severity of P. aeruginosa keratitis, as manifested by decreased inflammatory responses and reduced corneal epithelial defects. Consistent with these findings, WDL also dose-dependently alleviated LPS-induced noncanonical pyroptosis by reversing the increased expression of caspase-4/5 and GSDMD in piHCKs. In summary, our results demonstrated that by targeting the activation of caspase-4/5/11, wedelolactone inhibited the development of P. aeruginosa keratitis and suppressed the release of proinflammatory cytokines. Wedelolactone may be a promising anti-inflammatory candidate to combat P. aeruginosa keratitis.

Comparative Analysis of the Clinical Aspects and Treatment Outcomes of Stenotrophomonas maltophilia Keratitis and Pseudomonas aeruginosa Keratitis

OBJECTIVES

We analyzed the clinical aspects and treatment outcomes of Stenotrophomonas maltophilia (SM) keratitis and Pseudomonas aeruginosa (PA) keratitis.

METHODS

Medical records of 55 inpatients with culture-proven SM (n=21) and PA (n=34) keratitis were retrospectively reviewed. Predisposing factors, clinical characteristics, and treatment outcomes were compared between the SM and PA groups.

RESULTS

The mean symptom duration was longer in the SM group than in the PA group (10.4:4.3 days; P=0.012). The most common predisposing factor was corneal trauma (47.6%) in the SM group and contact-lens wear (38.2%) in the PA group. There were no differences in the mean epithelial defect size (12.7:11.9 mm2; P=0.861), hypopyon (33.3%:44.1%; P=0.428), surgical treatment (4.8%:14.7%; P=0.390), or poor clinical outcomes (26.8%:30.3%; P=0.760) between the SM and PA groups. In multivariate logistic regression, risk factors for poor clinical outcomes were hypopyon (odds ratio [OR], 52.00; P=0.010) in the SM group and symptom duration≥7 days (OR, 44.32; P=0.015), age≥60 years (OR, 21.13; P=0.019), and hypopyon (OR, 15.20; P=0.038) in the PA group.

CONCLUSION

Compared with PA keratitis, SM keratitis had slower progression, and its clinical characteristics and treatment results were not worse. In both groups, hypopyon was the risk factor for a poor clinical outcome.

An 18-Year Overview of Serratia marcescens Ocular Infection

PURPOSE

Serratia marcescens is a frequent ocular bacterial pathogen implicated in keratitis, endophthalmitis, and conjunctivitis. We evaluated the risk factors and treatment outcomes of ocular infections due to S. marcescens.

METHODS

In this retrospective observational study, all S. marcescens-positive cases between February 2002 and February 2020 were reviewed for ocular risk factors that included log of minimal angle of resolution visual acuity (VA), medical management, and time to epithelial defect closure.

RESULTS

Fifty-one patients were identified (72.5% females, 46.8±23.3 years). Forty-six patients had complete medical records, and 5 had microbiology data available. The most prevalent ocular risk factors were, contact lens (CL) use (68.6%), corneal disease (52.9%), and history of ocular surgery (41.2%). Mean presenting VA was 1.3±1.0. About half of the patients presented with a central ulcer (49%, 25), large infiltrate (20.4±31.8 mm2 mean), and hypopyon (43.1%, 22). All cases were reported to be susceptible to ciprofloxacin. Defect closure occurred in 52.3±117.1 days and final VA was 0.86±0.88. Adjunctive treatments were required in 14 cases (27.5%). One patient underwent surgical intervention. Features associated with poor VA outcomes included, history of glaucoma (P=0.038), older age at presentation (P<0.001), presence of hypopyon (0.045), poor VA at presentation (0.0086), time to epithelial defect closure (0.0196), and large infiltrate size (P=0.0345).

CONCLUSIONS

S. marcescens keratitis and conjunctivitis is associated with CL use and history of ocular surface disease. Worse outcomes were associated with older age, infiltrate size, presence of hypopyon, worse initial VA, longer time to epithelial defect closure, and history of glaucoma.

Efficacy of Voriconazole Corneal Intrastromal Injection for the Treatment of Fungal Keratitis

Purpose

To evaluate efficacy and safety of novel tricyclic corneal stroma injection (TCSI) voriconazole for the treatment of fungal keratitis.

Methods

This retrospective cohort study included data of 57 patients (57 eyes) with fungal keratitis. The TCSI group consisted of 27 patients (27 eyes) who were injected voriconazole once via TCSI procedure within one week after enrollment, in addition to conventional antifungal treatment. The control group consisted of 30 patients (30 eyes) who were treated using conventional antifungal treatment modalities. The outcome measures consist of the 3-week and 3-month best-corrected visual acuity (BCVA) values and size of infiltrate or scar, time to re-epithelialization, corneal perforation rate and/or therapeutic penetrating keratoplasty (TPK) requirement, the preoperative and post-TCSI corneal endothelial cell density (ECD), and the intraocular pressure (IOP) of the treated eye and the respective contralateral eye.

Results

There were no significant differences in the baseline demographic and clinical characteristics between the two groups. 3 weeks and 3 months after enrollment, the TCSI group exhibited an increase in visual acuity (P < 0.05), and there was no significant difference in the size of infiltrate or scar between two groups (P > 0.05). Time to re-epithelialization was shorter in the TCSI group than in the control group (P < 0.05). There was no statistically significant difference between corneal ECD on the day before and 7 days after TCSI and the IOP of treated and contralateral healthy eyes on the day before and 1 day, 3 days, 7 days, and 1 month after TCSI (P > 0.05). The difference in the risk of perforation and/or TPK requirement was not statistically significant between two groups (P > 0.05).

Conclusion

Localized injection of voriconazole using TCSI may be a minimally invasive, safe, and effective adjuvant treatment modality for fungal keratitis.

The Rcs Stress Response System Regulator GumB Modulates Serratia marcescens-Induced Inflammation and Bacterial Proliferation in a Rabbit Keratitis Model and Cytotoxicity In Vitro

In this study, we tested the hypothesis that the conserved bacterial IgaA-family protein, GumB, mediates microbial pathogenesis associated with Serratia marcescens ocular infections through regulation of the Rcs stress response system. The role of the Rcs system and bacterial stress response systems for microbial keratitis is not known, and the role of IgaA proteins in mammalian pathogenesis models has only been tested with partial-function allele variants of Salmonella. Here, we observed that an Rcs-activated gumB mutant had a >50-fold reduction in proliferation compared to the wild type within rabbit corneas at 48 h and demonstrated a notable reduction in inflammation based on inflammatory signs, including the absence of hypopyons, and proinflammatory markers measured at the RNA and protein levels. The gumB mutant phenotypes could be complemented by wild-type gumB on a plasmid. We observed that bacteria with an inactivated Rcs stress response system induced high levels of ocular inflammation and restored corneal virulence to the gumB mutant. The high virulence of the ΔrcsB mutant was dependent upon the ShlA cytolysin transporter ShlB. Similar results were found for testing the cytotoxic effects of wild-type and mutant bacteria on a human corneal epithelial cell line in vitro. Together, these data indicate that GumB regulates virulence factor production through the Rcs system, and this overall stress response system is a key mediator of a bacterium's ability to induce vision-threatening keratitis.

Hypopyon: Is-it Infective or Noninfective?

Hypopyon usually corresponds to the sedimentation of white blood cells, and it signifies severe intraocular inflammation. This key clinical sign may occur in association with a wide variety of infectious, inflammatory, and neoplastic conditions that may be sight- and, occasionally, life-threatening. A careful history and thorough clinical examination are the cornerstones for orienting the differential diagnosis, identifying the causative agent, and initiating prompt and appropriate treatment. This review outlines the clinical characteristics and management of hypopyon in relation with the underlying causative infectious or noninfectious ocular or systemic diseases.

Comparison of Clinical Features and Treatment Outcomes of Pseudomonas aeruginosa Keratitis in Contact Lens and Non-Contact Lens Wearers

PURPOSE

To compare the outcomes of Pseudomonas aeruginosa keratitis (PAK) in contact lens wearers (CLWs) and non-contact lens wearers (non-CLWs) and identify risk factors for poor visual acuity (VA) outcomes in each group.

DESIGN

Retrospective cohort study METHODS: Two hundred fourteen consecutive cases of PAK were included between January 2006 and December 2019. Clinical features, microbiologic results, and treatment course were compared between CLW and non-CLW groups. Analyses of clinical features predicting poor final VA were performed.

RESULTS

This study identified 214 infected eyes in 207 patients with PAK, including 163 eyes (76.2%) in CLWs and 51 eyes (23.8%) in non-CLWs. The average age was 39.2 years in CLWs and 71.9 years in non-CLWs (P < .0001). The average logMAR visual acuity (VA) at presentation was 1.39 in CLWs and 2.17 in non-CLWs (P < .0001); average final VA was 0.76 in CLWs and 1.82 in non-CLWs (P < .0001). Stromal necrosis required a procedural or surgical intervention in 13.5% of CLWs and 49.0% of non-CLWs (P < .0001). A machine learning-based analysis yielded a list of clinical features that most strongly predict a poor VA outcome (worse than 20/40), including worse initial VA, older age, larger size of infiltrate or epithelial defect at presentation, and greater maximal depth of stromal necrosis.

CONCLUSIONS

Non-CLWs have significantly worse VA outcomes and required a higher rate of surgical intervention, compared with CLWs. Our study elucidates risk factors for poor visual outcomes in non-CLWs with PAK.

Antibiotic Resistance in Pseudomonas spp. Through the Urban Water Cycle

Selection and dissemination of resistant bacteria and antibiotic resistance genes (ARGs) require a deeper understanding since antibiotics are permanently released to the environment. The objective of this paper was to evaluate the phenotypic resistance of 499 isolates of Pseudomonas spp. from urban water sources, and the prevalence of 20 ARGs within those isolates. Resistance to penicillins, cephalosporins, carbapenems, quinolones, macrolides, and tetracyclines was mainly observed in the hospital effluent, municipal wastewater and river water downstream the city. Resistant strains were frequently identified as P. aeruginosa and P. putida. P. aeruginosa isolates were mostly resistant to cefepime, ceftazidime, imipenem, and gentamycin, while P. putida strains were especially resistant to piperacillin-tazobactam. ARGs such as bla_TEM-1, bla_SHV-1, bla_PER-1, bla_AmpC, bla_VIM-1, PstS, qnrA, qnrB, ermB, tetA, tetB and tetC have been detected. The bla_AmpC gene was found in P. aeruginosa, while bla_TEM-1 and bla_PER-1 genes were found in P. putida. Class 1 integron integrase gene was found in 6.81% of the Pseudomonas isolates.

Bacterial and fungal causes of infectious keratitis among patients attending Research Institute of Ophthalmology

Background

Corneal ulcer is a potentially sight threatening ocular condition and the leading cause of monocular blindness in developing countries. Knowing the predisposing factors and etiologic microorganism can help prompt diagnosis and treatment to prevent devastating outcomes

The aim of this study was to detect the prevalence of bacteria and fungi in infectious keratitis. And to detect the antimicrobial susceptibility pattern against these causative bacterial and fungal pathogens using antibacterial and antifungal disces.

Results

Out of 50 cases (= 50 eyes), fungal growth was predominant 23/50 representing 46% with Aspergillus flavus being the most prevalent 14/23(61%). Bacterial growth was 7/50 (14%), 4/7 was gram-positive cocci (Staphylococcus aureus and Streptococcus pneumonie) and 3/7 was pseudomonas spp. While twenty out of 50 cases (40%) showed no growth.

Conclusion

Ocular trauma was the major cause of infectious keratitis, more in rural population. Fungal growth; mainly Aspergillus spp. was the most prevalent pathogen encountered in all cases. Voriconazole proved to be the first choice in the treatment of mould keratitis with 100% susceptibility. While alarmingly, fluconazole should no longer be used for the empirical therapy as it showed resistance to all the fungal isolates.

Bacterial Diversity and Antibiotic Susceptibility of Sparus aurata from Aquaculture

In a world where the population continues to increase and the volume of fishing catches stagnates or even falls, the aquaculture sector has great growth potential. This study aimed to contribute to the depth of knowledge of the diversity of bacterial species found in Sparus aurata collected from a fish farm and to understand which profiles of diminished susceptibility to antibiotics would be found in these bacteria that might be disseminated in the environment. One hundred thirty-six bacterial strains were recovered from the S. aurata samples. These strains belonged to Bacillaceae, Bacillales Family XII. Incertae Sedis, Comamonadaceae, Enterobacteriaceae, Enterococcaceae, Erwiniaceae, Micrococcaceae, Pseudomonadaceae and Staphylococcaceae families. Enterobacter sp. was more frequently found in gills, intestine and skin groups than in muscle groups (p ≤ 0.01). Antibiotic susceptibility tests found that non-susceptibility to phenicols was significantly higher in gills, intestine and skin samples (45%) than in muscle samples (24%) (p ≤ 0.01) and was the most frequently found non-susceptibility in both groups of samples. The group of Enterobacteriaceae from muscles presented less decreased susceptibility to florfenicol (44%) than in the group of gills, intestine and skin samples (76%). We found decreased susceptibilities to β-lactams and glycopeptides in the Bacillaceae family, to quinolones and mupirocin in the Staphylococcaceae family, and mostly to β-lactams, phenicols and quinolones in the Enterobacteriaceae and Pseudomonadaceae families. Seven Enterobacter spp. and five Pseudomonas spp. strains showed non-susceptibility to ertapenem and meropenem, respectively, which is of concern because they are antibiotics used as a last resort in serious clinical infections. To our knowledge, this is the first description of species Exiguobacterium acetylicum, Klebsiella michiganensis, Lelliottia sp. and Pantoea vagans associated with S. aurata (excluding cases where these bacteria are used as probiotics) and of plasmid-mediated quinolone resistance qnrB19-producing Leclercia adecarboxylata strain. The non-synonymous G385T and C402A mutations at parC gene (within quinolone resistance-determining regions) were also identified in a Klebsiella pneumoniae, revealing decreased susceptibility to ciprofloxacin. In this study, we found not only bacteria from the natural microbiota of fish but also pathogenic bacteria associated with fish and humans. Several antibiotics for which decreased susceptibility was found here are integrated into the World Health Organization list of "critically important antimicrobials" and "highly important antimicrobials" for human medicine.

Contact lens-related corneal infection: Intrinsic resistance and its compromise

Contact lenses represent a widely utilized form of vision correction with more than 140 million wearers worldwide. Although generally well-tolerated, contact lenses can cause corneal infection (microbial keratitis), with an approximate annualized incidence ranging from ~2 to ~20 cases per 10,000 wearers, and sometimes resulting in permanent vision loss. Research suggests that the pathogenesis of contact lens-associated microbial keratitis is complex and multifactorial, likely requiring multiple conspiring factors that compromise the intrinsic resistance of a healthy cornea to infection. Here, we outline our perspective of the mechanisms by which contact lens wear sometimes renders the cornea susceptible to infection, focusing primarily on our own research efforts during the past three decades. This has included studies of host factors underlying the constitutive barrier function of the healthy cornea, its response to bacterial challenge when intrinsic resistance is not compromised, pathogen virulence mechanisms, and the effects of contact lens wear that alter the outcome of host-microbe interactions. For almost all of this work, we have utilized the bacterium Pseudomonas aeruginosa because it is the leading cause of lens-related microbial keratitis. While not yet common among corneal isolates, clinical isolates of P. aeruginosa have emerged that are resistant to virtually all currently available antibiotics, leading the United States CDC (Centers for Disease Control) to add P. aeruginosa to its list of most serious threats. Compounding this concern, the development of advanced contact lenses for biosensing and augmented reality, together with the escalating incidence of myopia, could portent an epidemic of vision-threatening corneal infections in the future. Thankfully, technological advances in genomics, proteomics, metabolomics and imaging combined with emerging models of contact lens-associated P. aeruginosa infection hold promise for solving the problem - and possibly life-threatening infections impacting other tissues.

Risk factors and antimicrobial resistance profiles of Pseudomonas putida infection in Central China, 2010-2017

The aim of this study was to analyze the risk factors, clinical features, and antimicrobial resistance of Pseudomonas putida (P putida) isolated from Tongji Hospital in Wuhan, China.The data of 44 patients with P putida infections were retrospectively reviewed in this study. All cases of P putida strains were detected by the clinical laboratory of Tongji Hospital in the period of January 2010 to December 2017. Antimicrobial susceptibility testing was conducted using Kirby-Bauer method.Forty-four effective strains of P putida were isolated, including 32 inpatients and 12 outpatients. The 32 inpatients cases were obtained from various departments, which were urosurgery wards (n = 5, 15.6%), pediatrics wards (n = 4, 12.5%), hepatic surgery wards (n = 4, 12.5%), among others. The isolates had been discovered from urine specimens (28.2%), blood specimens (21.9%), sputum specimens (12.5%), and so on. Twenty-five patients had histories of catheterization before the isolation of P putida. Twenty-four patients were in immunocompromised states, 5 patients had undergone surgery, catheterization and were taking immunosuppressive therapy simultaneously. Polymicrobial infections were found in some P putida cases, especially Stenotrophomonas maltophilia, Pseudomonas aeruginosa, and Escherichia coli. All the patients had treated by antimicrobial before culture. Multi-drug-resistant strains were detected in 75% of P putida isolates. The P putida strains were resistant to trimethoprim/sulfamethoxazole (97.7%), aztreonam (88.6%), minocyline (74.3%), ticarcillin/clavulanic acid (72.7%), and sensitive to amikacin (86.4%), imipenem (62.8%), gentamicin (56.8%).Catheterization or other invasive procedures, immunocompromised states, and underlying diseases increased the risks of P putida infections. Moreover, the P putida strains were highly resistant to trimethoprim/sulfamethoxazole, aztreonam, minocyline, ticarcillin/clavulanic acid.