Secondary Angle Closure Caused by Anterior Displacement of Capsular Tension Ring and Intraocular Lens Due to Aqueous Misdirection.

A capsular tension ring (CTR) is used for support to stabilize the capsular bag and intraocular lens (IOL) during and after cataract surgery. Although complications involving the CTR-IOL complex are not uncommon, cases of anterior displacement leading to complications are rare. This report presents a case of secondary angle closure caused by anterior displacement of the CTR-IOL complex due to aqueous misdirection and reports unique findings noted on anterior segment optical coherence tomography (AS-OCT). The patient, a 69-year-old woman, developed an acute angle closure crisis (AACC) and underwent cataract surgery with the implantation of a CTR and IOL. Post-surgery, there was an improvement in the central depth of the anterior chamber, but the patient experienced intermittent spikes in intraocular pressure. AS-OCT revealed a flat center of the iris and a closed anterior chamber angle which are plateau-iris-like findings. Secondary angle closure was caused by the CTR-IOL complex which was anteriorly displaced and pushed the peripheral iris owing to aqueous misdirection syndrome. Three weeks after the initial surgery, the patient underwent CTR removal, anterior vitrectomy, and intrascleral lens fixation. After the second surgery, intraocular pressure was normalized without any medications, and the anterior chamber angle was enlarged. This case provides a better understanding of secondary angle closure caused by the anterior displacement of the CTR-IOL complex and highlights the importance of AS-OCT in the detection of such complications.

Disease-specific variant interpretation highlighted the genetic findings in 2325 Japanese patients with retinitis pigmentosa and allied diseases.

BACKGROUND: As gene-specific therapy for inherited retinal dystrophy (IRD) advances, unified variant interpretation across institutes is becoming increasingly important. This study aims to update the genetic findings of 86 retinitis pigmentosa (RP)-related genes in a large number of Japanese patients with RP by applying the standardised variant interpretation guidelines for Japanese patients with IRD (J-IRD-VI guidelines) built upon the American College of Medical Genetics and Genomics and the Association for Molecular Pathology rules, and assess the contribution of these genes in RP-allied diseases. METHODS: We assessed 2325 probands with RP (n=2155, including n=1204 sequenced previously with the same sequencing panel) and allied diseases (n=170, newly analysed), including Usher syndrome, Leber congenital amaurosis and cone-rod dystrophy (CRD). Target sequencing using a panel of 86 genes was performed. The variants were interpreted according to the J-IRD-VI guidelines. RESULTS: A total of 3564 variants were detected, of which 524 variants were interpreted as pathogenic or likely pathogenic. Among these 524 variants, 280 (53.4%) had been either undetected or interpreted as variants of unknown significance or benign variants in our earlier study of 1204 patients with RP. This led to a genetic diagnostic rate in 38.6% of patients with RP, with EYS accounting for 46.7% of the genetically solved patients, showing a 9% increase in diagnostic rate from our earlier study. The genetic diagnostic rate for patients with CRD was 28.2%, with RP-related genes significantly contributing over other allied diseases. CONCLUSION: A large-scale genetic analysis using the J-IRD-VI guidelines highlighted the population-specific genetic findings for Japanese patients with IRD; these findings serve as a foundation for the clinical application of gene-specific therapies.

Myth or truth: investigation of the jumping ability of Tunga penetrans (Siphonaptera: Tungidae).

Female sand fleas (Tunga penetrans Linnaeus, 1758, Siphonaptera: Tungidae) cause a severe parasitic skin disease known as tungiasis. T. penetrans is a small flea, measuring less than 1 mm in length. The females of this species burrow into the skin of human and animal hosts and mostly affect the feet. This has led to the anecdotal assumption that T. penetrans, unlike its relatives in the Siphonaptera family, would have a limited jumping ability potentially not reaching higher body parts. However, there is no data supporting this. This study evaluated the jumping capabilities of T. penetrans for height and distance using sticky tapes. The vertical jump of the female T. penetrans ranged from 4.5 to 100 mm with a mean of 40 mm whereas the vertical jump of the male T. penetrans ranged from 1.2 to 138 mm with a mean of 46 mm. The horizontal jump of the female T. penetrans ranged from 18 to 138 mm with a mean of 64 mm and that of the male ranged from 9 to 251 mm with a mean of 80 mm. Based on the literature, fleas of various species have been described as jumping vertically 50-100 times their size and horizontally 5-100 times their size. In this respect, sand fleas appear to have equal expert jumping abilities to their relatives. Their aggregation on people's feet is not likely a result of their poor jumping ability but might be an adaptation to the host's behavior which would require further investigations.

Narrowing Ratio of Retinal Veins at Arteriovenous Crossing in Patients With Branch Retinal Vein Occlusion Versus That in Healthy Individuals.

Purpose: This cross-sectional study aimed to clarify the differences in the retinal venous narrowing ratio (VNR) at retinal arteriovenous crossing by optical coherence tomography (OCT) among the eyes with branch retinal vein occlusion (BRVO), fellow eyes of patients with BRVO, and eyes of individuals without BRVO and to determine factors that influence the VNR. Methods: We studied 31 eyes of young participants, 54 eyes of an older control group, 56 fellow eyes of patients with BRVO, and 48 eyes with BRVO. Cross-sectional OCT images were used to determine the VNR at two arteriovenous crossings per eye. Results: Overall, 378 arteriovenous crossings were analyzed. The VNR of arterial overcrossings of fellow eyes (27.7% ± 11.1%) and BRVO eyes (27.3% ± 9.76%) were significantly higher than those in the young (16.0% ± 7.9%, all P < 0.001) and control (22.0% ± 8.81%, P < 0.001, P = 0.003, respectively) groups. The VNR of arterial overcrossings was significantly larger than that of venous overcrossings (24.0% ± 10.5% vs. 20.6% ± 13.0%, P = 0.021). A linear mixed-effects model showed that the VNR was significantly higher in arterial overcrossings, crossings with larger arterial internal diameters, smaller venous internal diameters, and participants with older age and a BRVO history. Conclusions: The VNR in arterial overcrossings was higher in BRVO eyes and even in the fellow eyes. Thus, a higher VNR in arterial overcrossings may contribute to BRVO development, and crossings with factors contributing to higher VNR might be associated with a risk of BRVO.

Relationship between tinnitus and olfactory dysfunction: audiovisual, olfactory, and medical examinations.

Introduction: Sensory dysfunctions and cognitive impairments are related to each other. Although a relationship between tinnitus and subjective olfactory dysfunction has been reported, there have been no reports investigating the relationship between tinnitus and olfactory test results. Methods: To investigate the relationship between tinnitus and olfactory test results, we conducted sensory tests, including hearing and visual examinations. The subjects included 510 community-dwelling individuals (295 women and 215 men) who attended a health checkup in Yakumo, Japan. The age of the subjects ranged from 40 to 91 years (mean ± standard deviation, 63.8 ± 9.9 years). The participants completed a self-reported questionnaire on subjective tinnitus, olfactory function, and hearing function, as well as their lifestyle. The health checkup included smell, hearing, vision, and blood examinations. Results: After adjusting for age and sex, the presence of tinnitus was significantly associated with subjective olfactory dysfunction, poor olfactory test results, hearing deterioration, vertigo, and headache. Additionally, high serum calcium levels and a low albumin/globulin ratio were significantly associated with low physical activity and nutrition. Women scored higher than men in olfactory and hearing examinations, but there was no gender difference in vision examinations. Conclusion: Subjective smell dysfunction and poor smell test results were significantly associated with tinnitus complaints. Hearing and vision were associated even after adjusting for age and sex. These findings suggest that evaluating the mutual relationships among sensory organs is important when evaluating the influence of sensory dysfunctions on cognitive function.

Snakebite victim profiles and treatment-seeking behaviors in two regions of Kenya: results from a health demographic surveillance system.

INTRODUCTION: Snakebites are a major cause of permanent injury and death among poor, rural populations in developing countries, including those in East Africa. This research characterizes snakebite incidence, risk factors, and subsequent health-seeking behaviors in two regions of Kenya using a mixed methods approach. METHODS: As a part of regular activities of a health demographic surveillance system, household-level survey on snakebite incidence was conducted in two areas of Kenya: Kwale along the Kenyan Coast and Mbita on Lake Victoria. If someone in the home was reported to have been bitten in the 5 years previous to the visit, a survey instrument was administered. The survey gathered contextual information on the bite, treatment-seeking behavior and clinical manifestations. To obtain deeper, contextual information, respondents were also asked to narrate the bite incident, subsequent behavior and outcomes. RESULTS: 8775 and 9206 households were surveyed in Kwale and Mbita, respectively. Out of these, 453 (5.17%) and 92 (1.00%) households reported that at least one person had been bitten by a snake in the past 5 years. Deaths from snakebites were rare (4.04%), but patterns of treatment seeking varied. Treatment at formal care facilities were sought for 50.8% and at traditional healers for 53.3%. 18.4% sought treatment from both sources. Victims who delayed receiving treatment from a formal facility were more likely to have consulted a traditional healer (OR 8.8995% CI [3.83, 20.64]). Delays in treatment seeking were associated with significantly increased odds of having a severe outcome, including death, paralysis or loss of consciousness (OR 3.47 95% CI [1.56; 7.70]). CONCLUSION: Snakebite incidence and outcomes vary by region in Kenya, and treatment-seeking behaviors are complex. Work needs to be done to better characterize the spatial distribution of snakebite incidence in Kenya and efforts need to be made to ensure that victims have sufficient access to effective treatments to prevent death and serious injury.

Elevated retinal artery vascular resistance determined by novel visualized technique of laser speckle flowgraphy in branch retinal vein occlusion.

We aimed to investigate the increase in resistivity of the retinal artery in the branch retinal vein occlusion (BRVO)-affected area, and to visualize it. Thirty-two eyes of 32 patients with BRVO were measured by laser speckle flowgraphy (LSFG). The retinal artery and vein running to the BRVO-affected area and vertically symmetrical vessels in the unaffected area were examined. We applied the LSFG parameter beat strength over mean blur rate (BOM), calculated using a similar method to the pulsatility index used in Doppler flowmetry to evaluate resistivity of the vessels. Our results showed that the BOM map could clearly visualize the increase of resistivity in the retinal artery as a two-dimensional map. The BOM of the arteries in the affected area was significantly higher than that of the unaffected area (P = 0.001). Multiple regression analysis showed that the ratio of BOM in retinal arteries of the affected area to the unaffected was significantly associated with the extent of retinal hemorrhage (ß = 0.447, P = 0.009). In conclusion, the index of resistivity of the retinal artery in the BRVO-affected area was higher and could be visualized in a two-dimensional map. These findings and techniques would contribute to elucidate the pathophysiology of BRVO.

Presence of dogs and proximity to a wildlife reserve increase household level risk of tungiasis in Kwale, Kenya.

INTRODUCTION: Tungiasis is a ectopic skin disease caused by some species of fleas in the Tunga genus, most notably T. penetrans. The disease afflicts poor and marginalized communities in developing countries. Transmission of tungiasis comprises a complex web of factors including domesticated animals and wildlife. This research explores animal and environmental risk factors for tungiasis in an area adjacent to a wildlife reserve in Kwale, Kenya. METHODS: A two-stage complex sampling strategy was used. Households were selected from three areas in and around Kwale Town, Kenya, an area close to the Kenyan Coast. Households were listed as positive if at least one member had tungiasis. Each household was administered a questionnaire regarding tungiasis behaviors, domesticated animal assets, and wild animal species that frequent the peridomiciliary area. Associations of household tungiasis were tests with household and environmental variables using regression methods. RESULTS: The study included 319 households. Of these, 41 (12.85%) were found to have at least one person who had signs of tungiasis. There were 295 (92.48%) households that possessed at least one species of domesticated animal. It was reported that wildlife regularly come into the vicinity of the home 90.59% of households. Presence of dogs around the home (OR 3.85; 95% CI 1.84; 8.11) and proximity to the park were associated with increased risk for tungiasis infestation in humans in a multivariate regression model. CONCLUSIONS: Human tungiasis is a complex disease associated with domesticated and wild animals. Canines in particular appear to be important determinants of household level risk.

Association of changes of retinal vessels diameter with ocular blood flow in eyes with diabetic retinopathy.

We investigated morphological changes of retinal arteries to determine their association with the blood flow and systemic variables in type 2 diabetes patients. The patients included 47 non-diabetic retinopathy eyes, 36 mild or moderate nonproliferative diabetic retinopathy (M-NPDR) eyes, 22 severe NPDR (S-NPDR) eyes, 32 PDR eyes, and 24 normal eyes as controls. The mean wall to lumen ratio (WLR) measured by adaptive optics camera was significantly higher in the PDR groups than in all of the other groups (all P < 0.001). However, the external diameter of the retinal vessels was not significantly different among the groups. The mean blur rate (MBR)-vessel determined by laser speckle flowgraphy was significantly lower in the PDR group than in the other groups (P < 0.001). The WLR was correlated with MBR-vessel (r = - 0.337, P < 0.001), duration of disease (r = 0.191, P = 0.042), stage of DM (r = 0.643, P < 0.001), systolic blood pressure (r = 0.166, P < 0.037), and presence of systemic hypertension (r = 0.443, P < 0.001). Multiple regression analysis demonstrated that MBR-vessel (ß = - 0.389, P < 0.001), presence of systemic hypertension (ß = 0.334, P = 0.001), and LDL (ß = 0.199, P = 0.045) were independent factors significantly associated with the WLR. The increased retinal vessel wall thickness led to a narrowing of lumen diameter and a decrease in the blood flow in the PDR group.

Environmental and Household-Based Spatial Risks for Tungiasis in an Endemic Area of Coastal Kenya.

Tungiasis is a cutaneous parasitosis caused by an embedded female sand flea. The distribution of cases can be spatially heterogeneous even in areas with similar risk profiles. This study assesses household and remotely sensed environmental factors that contribute to the geographic distribution of tungiasis cases in a rural area along the Southern Kenyan Coast. Data on household tungiasis case status, demographic and socioeconomic information, and geographic locations were recorded during regular survey activities of the Health and Demographic Surveillance System, mainly during 2011. Data were joined with other spatial data sources using latitude/longitude coordinates. Generalized additive models were used to predict and visualize spatial risks for tungiasis. The household-level prevalence of tungiasis was 3.4% (272/7925). There was a 1.1% (461/41,135) prevalence of infection among all participants. A significant spatial variability was observed in the unadjusted model (p-value < 0.001). The number of children per household, earthen floor, organic roof, elevation, aluminum content in the soil, and distance to the nearest animal reserve attenuated the odds ratios and partially explained the spatial variation of tungiasis. Spatial heterogeneity in tungiasis risk remained even after a factor adjustment. This suggests that there are possible unmeasured factors associated with the complex ecology of sand fleas that may contribute to the disease's uneven distribution.

Association between displacement and thickness of macula after vitrectomy in eyes with epiretinal membrane.

The purpose of this cross-sectional retrospective study was to determine the relationship between the retinal displacements and the retinal thickness in eyes with epiretinal membrane (ERM) after vitrectomy with internal limiting membrane (ILM) peeling. To accomplish this, we measured the retinal thickness using optical coherence tomography (OCT) and the retinal displacement using OCT angiography to obtain 3 mm × 3 mm en face images before, and 2, 4, and 8 weeks following the surgery from 20 eyes of 20 patients. The distance between the retinal vessel bifurcations and the fovea was significantly displaced centrifugally and asymmetrically in the 4 quadrants postoperatively (P < 0.001). The foveal avascular zone (FAZ) was significantly enlarged, and the central foveal thickness (CFT) and the inner nuclear layer (INL) thickness were significantly thinner postoperatively. The displacements were significantly correlated with the changes in the FAZ area (r = 0.717, P < 0.001), the CFT (r = - 0.702, P < 0.001), and the INL thickness (r = - 0.702, P < 0.001). In conclusion, the distance between the retinal bifurcations and the fovea was asymmetrically expanded after the surgery and was significantly correlated with the morphological changes. These results indicate that a horizontal macular contraction is correlated with vertical retinal contraction in the eyes with an ERM.

Differences in Blood Flow Between Superior and Inferior Retinal Hemispheres.

Purpose: To determine whether the blood flow in the superior retina is significantly different from that in the inferior retina, and to determine whether the posture affects the blood flow in the superior and inferior retina. Methods: The blood flow in the vessels around the optic nerve head was measured by laser speckle flowgraphy in the sitting position in 68 healthy subjects. The blood flow in the superior peripapillary retina was compared with that in the inferior peripapillary retina. The measurements of the blood flow were performed in the sitting position, and the effect of switching to a supine position was determined at 2, 4, 6, 8, 10, and 30 minutes after the switch. Results: The total relative flow volume (RFV)-all, RFV-artery, and RFV-vein were significantly greater in the superior retina than in the inferior retina (all P < 0.001). The mean diameter-all and mean diameter-artery in the superior retina were significantly larger than that in the inferior retina (all P < 0.05). The mean blur rate (MBR)-all, MBR-artery, and MBR-vein in the superior retina were also greater than that in the inferior retina (P < 0.001, P < 0.01, and P < 0.001, respectively). Although the ocular perfusion pressure was significantly changed with the postural alteration, the total RFV-all remained greater in the superior retina than in the inferior retina after the postural change. Conclusions: Clinicians need to be aware of the differences in the blood flow between the superior and inferior retinal peripapillary area when considering the mechanisms of retinochoroidal diseases.

Correlations between intraretinal cystoid cavities and pre- and postoperative characteristics of eyes after closure of idiopathic macular hole.

Intraretinal cystoid cavities have been detected at the edges of macular holes (MHs) but their clinical characteristics and their relationship to the MH variables have not been determined. We measured the areas of the intraretinal cystoid cavity in 111 eyes with MHs in the OCT images preoperatively. Our results showed that the intraretinal cystoid cavities were located in the Henle fiber layer-outer nuclear layer (HFL-ONL) complex in 106 eyes and in the inner nuclear layer (INL) in 89 eyes. All were resolved after the initial vitrectomy to close the MH. The mean area of the cystoid cavity was greater in the HFL-ONL complex (55.9 ± 42.7 × 103 µm2) than in the INL (9.1 ± 9.8 × 103 µm2; P < 0.001). The area of the cystoid cavities was significantly correlated with the basal MH size (r = 0.465,P < 0.001), the external limiting membrane height (r = 0.793, P < 0.001), and the maximum retinal thickness (r = 0.757, P < 0.001). The area of the cystoid cavities was significantly correlated with the preoperative best-corrected visual acuity (BCVA; r = 0.361, P < 0.001), but not with the postoperative BCVA or the integrity of any of the outer retinal microstructural bands. The presence of intraretinal cystoid cavities was related to some morphological characteristics, but not to the postoperative BCVA or the restoration of the outer retinal bands.

Choroidal and retinal displacements after vitrectomy with internal limiting membrane peeling in eyes with idiopathic macular hole.

It has been reported that the macular region of the retina is displaced after vitrectomy with internal limiting membrane (ILM) peeling in eyes with macular hole (MH), but the displacements of the deeper layers of the eye, e.g. RPE and choroid are unclear following the surgery. We used optical coherence tomography (OCT) and OCT angiography (OCTA) to obtain 3 mm × 3 mm en face images before, and 2, 4, and 8 weeks following the vitrectomy with internal limiting membrane (ILM) peeling from 22 eyes of 22 patients with a MH. The OCT and OCTA images showed displacements of the fovea and choroidal intermediate vessels postoperatively. The degree of displacement of the choroid was significantly less than that of the retina (P < 0.001). The displacements of the choroidal bifurcations were significantly correlated to their preoperative distance from the optic disc (r = -0.467, P < 0.001) and they were significantly correlated with the retinal displacements (r = 0.535, P < 0.001). The retina was displaced inferiorly and centripetally, but these localized displacements were not observed in the choroid. In conclusion, clinicians need to be aware of these displacements when evaluating the subfoveal choroid following the surgery because the displacement is different between the retina and the choroid.

Correlation between macular vessel density and number of intravitreal anti-VEGF agents for macular edema associated with branch retinal vein occlusion.

We evaluated whether the reduction of macular vessel density was correlated with the number of intravitreal injections of anti-vascular endothelial growth factor (VEGF) agents in eyes with a branch retinal vein occlusion (BRVO). The mean vessel density was determined by optical coherence tomography angiography in 29 eyes with macular edema associated with a BRVO. Our results showed that the mean vessel density in the group that had a resolution of the macular edema after one anti-VEGF injection was significantly higher than group that had a recurrence of the macular edema (P = 0.028). Single regression analysis showed that the number of intravitreal injections was significantly correlated with the reduction of the modified vessel density (r = -0.421, P = 0.023) and systemic hypertension (r = 0.377, P = 0.044). Multiple stepwise regression analysis showed that the reduction of the modified vessel density (ß = -0.442, P = 0.009) and hypertension (ß = 0.403, P = 0.016) were independent factors associated with the number of intravitreal injections. We conclude that the vessel density reduction can be used to predict whether recurrences of the macular edema will develop after the initial anti-VEGF injection in eyes with macular edema associated with a BRVO.

Spatial Distributions of HIV Infection in an Endemic Area of Western Kenya: Guiding Information for Localized HIV Control and Prevention.

HIV is still a major health problem in developing countries. Even though high HIV-risk-taking behaviors have been reported in African fishing villages, local distribution patterns of HIV infection in the communities surrounding these villages have not been thoroughly analyzed. The objective of this study was to investigate the geographical distribution patterns of HIV infection in communities surrounding African fishing villages. In 2011, we applied age- and sex-stratified random sampling to collect 1,957 blood samples from 42,617 individuals registered in the Health and Demographic Surveillance System in Mbita, which is located on the shore of Lake Victoria in western Kenya. We used these samples to evaluate existing antibody detection assays for several infectious diseases, including HIV antibody titers. Based on the results of the assays, we evaluated the prevalence of HIV infection according to sex, age, and altitude of participating households. We also used Kulldorff's spatial scan statistic to test for HIV clustering in the study area. The prevalence of HIV at our study site was 25.3%. Compared with the younger age group (15-19 years), adults aged 30-34 years were 6.71 times more likely to be HIV-positive, and the estimated HIV-positive population among women was 1.43 times larger than among men. Kulldorff's spatial scan statistic detected one marginally significant (P = 0.055) HIV-positive and one significant HIV-negative cluster (P = 0.047) in the study area. These results suggest a homogeneous HIV distribution in the communities surrounding fishing villages. In addition to individual behavior, more complex and diverse factors related to the social and cultural environment can contribute to a homogeneous distribution pattern of HIV infection outside of African fishing villages. To reduce rates of transmission in HIV-endemic areas, HIV prevention and control programs optimized for the local environment need to be developed.

Long-Term Colonization by bla(CTX-M)-Harboring Escherichia coli in Healthy Japanese People Engaged in Food Handling.

The actual state of intestinal long-term colonization by extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli in healthy Japanese people remains unclear. Therefore, a total of 4,314 fecal samples were collected from 2,563 food handlers from January 2010 to December 2011. Approximately 0.1 g of each fecal sample was inoculated onto a MacConkey agar plate containing cefotaxime (1 µg/ml). The bacterial colonies that grew on each plate were checked for ESBL production by the double-disk synergy test, as recommended by the Clinical and Laboratory Standards Institute. The bacterial serotype, antimicrobial susceptibility, pulsotype, sequence type (ST), and ESBL genotype were checked, and the replicon types of plasmids harboring the ESBL gene were also determined after conjugation experiments. ESBL producers were recovered from 70 (3.1%) of 2,230 participants who were checked only once. On the other hand, ESBL producers were isolated at least once from 52 (15.6%) of 333 participants who were checked more than twice, and 13 of the 52 participants carried ESBL producers for from more than 3 months to up to 2 years. Fluoroquinolone (FQ)-resistant E. coli strains harboring bla(CTX-M) were repeatedly recovered from 11 of the 13 carriers of bla(CTX-M)-harboring E. coli. A genetically related FQ-resistant E. coli O25b:H4-ST131 isolate harboring bla(CTX-M)-27 was recovered from 4 of the 13 carriers for more than 6 months. Three FQ-resistant E. coli O1:H6-ST648 isolates that harbored bla(CTX-M-15) or bla(CTX-M)-14 were recovered from 3 carriers. Moreover, multiple CTX-M-14- or CTX-M-15-producing E. coli isolates with different serotypes were recovered from 2 respective carriers. These findings predict a provable further spread of ESBL producers in both community and clinical settings.

Contribution of QnrA, a Plasmid-Mediated Quinolone Resistance Peptide, to Survival of Escherichia coli Exposed to a Lethal Ciprofloxacin Concentration.

We evaluated the effects of qnrA on survival of bacteria exposed to a lethal ciprofloxacin (CIP) concentration and development of quinolone resistance through the accumulation of amino acid substitutions in quinolone resistance-determining regions (QRDRs) of GyrA and ParC, targets of quinolones, in Escherichia coli. CIP-susceptible E. coli strains of different O-serotypes (O1, O6, O18, O25b, O74, and O78) were transformed by a recombinant plasmid harboring qnrA, and the parent strains and their transformants were subjected to killing curve assays and adaptation tests. In the killing curve assay at 2 × the minimum inhibitory concentration of CIP, the viable bacterial cell numbers of strains O1, O6, and O25b were maintained at 10(5)-10(8) CFU/mL after 24-h incubation, while the remaining strains showed a 10(5)-fold reduction in viable cell numbers. In the adaptation test, a Ser83-Leu substitution in the QRDR of GyrA was identified earlier in the parent strains of O25b and O1 than in their transformants, suggesting that the acquisition of qnrA did not necessarily accelerate the rate of accumulation of amino acid substitutions in the QRDR. We confirmed that the presence of qnrA contributed to increased survival of the E. coli strains displaying certain O-serotypes. Further studies are necessary to evaluate the precise effects of qnrA on quinolone resistance acquisition by Enterobacteriaceae.

Molecular epidemiology of extended-spectrum ß-lactamases and Escherichia coli isolated from retail foods including chicken meat in Japan.

Contamination of retail meat with extended-spectrum ß-lactamase (ESBL)-producing Escherichia coli has been reported, but only limited data have been documented in Japan. One hundred fifty-three retail foods including chicken meat, beef, pork, and vegetables were purchased from 29 supermarkets between January and October in 2010. ESBL producers were recovered from each food sample using McConkey agar plate supplemented with 1 mg/L of cefotaxime. ESBL type was identified by DNA sequencing analysis after polymerase chain reaction amplification. Antibiogram, O serotype, plasmid replicon type, pulsotype, and multilocus sequence type were also determined. Fifty-two epidemiologically unrelated Escherichia coli isolates producing ESBL were recovered from 35 (22.9%) of 153 samples, all of which were chicken meat. ESBL types were mainly CTX-M-2 group followed by CTX-M-1 group and CTX-M-8 group. The numbers of bacterial isolates (8 of 21, 38.1%) harboring bla(CTX-M-8) recovered from imported meat samples were significantly larger than those of domestic ones (one of 31, 3.2%) (p<0.05). Nine O serotypes (mainly O8, O25, and O1) were found, together with O-antigen untypable (OUT). Four E. coli belonging to the O25b:H4-ST131 clone were recovered from domestic (n=1) and imported meat samples (n=3), respectively. These four isolates were susceptible to fluoroquinolones, although the E. coli O25b:H4-ST131 clone producing CTX-M-15, which is predominant in human isolates, is usually resistant to fluoroquinolones. By contrast, five CTX-M-15-producing E. coli strains were recovered only from domestic meat samples, and their serotypes were O8 or OUT instead of predominant serotype O25b. Our results showed that ESBL-producing E. coli isolates recovered from retail chicken meat samples in Japan are generally divergent in both genetic and serological aspects. Further comparative analyses of bla(CTX-M)-mediating genetic elements would be continued in the next step to characterize the ESBL producers from retail foods in Japan.

Analysis of effects of meteorological factors on dengue incidence in Sri Lanka using time series data.

In tropical and subtropical regions of eastern and South-eastern Asia, dengue fever (DF) and dengue hemorrhagic fever (DHF) outbreaks occur frequently. Previous studies indicate an association between meteorological variables and dengue incidence using time series analyses. The impacts of meteorological changes can affect dengue outbreak. However, difficulties in collecting detailed time series data in developing countries have led to common use of monthly data in most previous studies. In addition, time series analyses are often limited to one area because of the difficulty in collecting meteorological and dengue incidence data in multiple areas. To gain better understanding, we examined the effects of meteorological factors on dengue incidence in three geographically distinct areas (Ratnapura, Colombo, and Anuradhapura) of Sri Lanka by time series analysis of weekly data. The weekly average maximum temperature and total rainfall and the total number of dengue cases from 2005 to 2011 (7 years) were used as time series data in this study. Subsequently, time series analyses were performed on the basis of ordinary least squares regression analysis followed by the vector autoregressive model (VAR). In conclusion, weekly average maximum temperatures and the weekly total rainfall did not significantly affect dengue incidence in three geographically different areas of Sri Lanka. However, the weekly total rainfall slightly influenced dengue incidence in the cities of Colombo and Anuradhapura.