Yueh Ren Ho

Emergence of Fluoroquinolone Resistance in Group B Streptococcal Isolates in Taiwan

ABSTRACT Of 1,994 group B streptococcal isolates collected, 26 (1.3%) of the isolates were resistant to levofloxacin, and cross-resistance to other fluoroquinolones was observed. The emergence and prevalence of high-level fluoroquinolone resistance in genetically unrelated isolates were linked to the presence of gyrA, parC, and parE triple mutations in each isolate.

The Prevalence of Erythromycin Resistance in Group B Streptococcal Isolates at a University Hospital in Taiwan

Due to reduced antibiotic consumption in Taiwan, erythromycin resistance rate had decreased in Streptococcus pyogenes, but it increased in Streptococcus pneumoniae. The objectives of the present study were (1) to determine the erythromycin and clindamycin resistance rate and minimum inhibitory concentration (MIC) of the group B streptococcus (GBS) clinical isolates, and (2) to investigate the mechanism responsible for the macrolide, lincosamide, and group B streptogramin (MLS(B)) resistance. A total of 1,395 GBS isolates were collected from June 2001 to April 2007. Forty-four percent of the GBS isolates were resistant to erythromycin, and 39% were resistant to clindamycin. The annual erythromycin resistance rate increased from 32% in 2001 to 51% in 2004; a significant decrease was observed in 2005 (47%), 2006 (42%), and 2007 (38%). Percentage of erythromycin-resistant isolates with erm(B) gene significantly increased from 72% in 2001 to 90% in 2007. We found that the plasmid encoded zeta gene was present in 13% of the resistant isolates, along with erm(B). When compared to our previous study (1991 to May 2001), the overall erythromycin resistance rate increased from 30% to 44%. erm(B) was the major resistant determinant, and zeta toxin encoding plasmid has a limited role in mediating erythromycin resistance unlike in GAS isolates as reported earlier.

Synchronizing chaotification with support vector machine and wolf pack search algorithm for estimation of peripheral vascular occlusion in diabetes mellitus

Abstract This study proposes a method for the estimation of peripheral vascular occlusion (PVO) in diabetic foot using a support vector machine (SVM) classifier with the wolf pack search (WPS) algorithm. The long-term presence of elevated blood sugar levels commonly results in peripheral neuropathy, peripheral vascular disease, nephropathy, and retinopathy in patients with Type 2 diabetes mellitus. Patients with PVO disease have decreased walking capability and life quality in diabetes mellitus and poor peripheral circulation of PVO causes morbidity like infection and amputation of the legs or feet of diabetics. This progressively vascular occlusion is often ignored by the patients and primary care physicians in early stage. Therefore, a reliable method of diagnostic assistance is crucial for early diagnosis and monitoring of PVO and prevention of amputation. Photoplethysmography (PPG) is a non-invasive technique for detecting blood volume changes in peripheral vascular bed. Literature indicates that the pulse transit time increases and waveform shape changes increase in PPG of the vascular occlusion. PPG pulses of feet gradually become asynchronous due to the different speed of deteriorating patency and collateral circulation in the peripheral arteries. We utilized synchronizing chaotification to compare the bilateral similarity and asymmetry of PPG signals, and applied SVM to estimate three degrees of PVO. Among 33 subjects tested, this classification technique could recognize various butterfly motion patterns representing severities successfully including normal condition, lower-degree disease, and higher-degree disease. The proposed method has potential for providing diagnostic assistance for PVO of diabetics and other high-risk populations, with efficiency and higher accuracy.

Variation in the Number of Tandem Repeats and Profile of Surface Protein Genes among Invasive Group B Streptococci Correlates with Patient Age

ABSTRACT The average number of tandem repeats of the rib gene (which encodes the Rib surface protein) in invasive group B streptococci from 29 neonates was smaller than that from 20 adults (6.8 and 8.6, respectively; P < 0.05), implying a distinct contribution of immunity toward this age-related variation.

emm1/Sequence Type 28 Strains of Group A Streptococci That Express covR at Early Stationary Phase Are Associated with Increased Growth and Earlier SpeB Secretion

ABSTRACT Streptococcus pyogenes (group A streptococcus [GAS]) is a versatile human pathogen, and emm1/sequence type 28 (ST28) is the most frequently isolated type from GAS infections. The emm1/ST28 strain is associated with necrotizing fasciitis and streptococcal toxic shock syndrome. Growth-phase regulation is one of the important regulatory mechanisms in GAS, which controls gene expression at restricted phases of growth. CovRS, a two-component regulatory system, is considered the regulator of streptococcal pyrogenic exotoxin B (SpeB) and is thought to be activated in the exponential phase of growth. In the present study, Northern hybridization analysis showed that 52% of the analyzed GAS strains expressed covR at the exponential phase, but 48% of the strains expressed covR at the early stationary phase of growth. Strains transcribing covR at the early stationary phase showed better growth and earlier SpeB expression than the other group of strains. Multilocus sequence typing and pulsed-field gel electrophoresis analysis showed only emm1/ST28 strains (which comprise a clonal cluster) were expressing covR at the early stationary phase of growth, indicating that emm1/ST28 strains have special characteristics which may be related to their worldwide distribution.

Epidemiology of and prenatal molecular distinction between invasive and colonizing group B streptococci in The Netherlands and Taiwan

The identification of markers for virulent group B streptococci (GBS) could guide prenatal prevention and intervention strategies. We compared the distribution of serotypes and potential pathogenicity islands (PPIs) between invasive and colonizing GBS. Colonizing and invasive strains from The Netherlands and Taiwan were serotyped. We used polymerase chain reaction (PCR) for the amplification of several new PPI markers. Several combinations of PPI-specific markers and serotypes were associated with invasiveness. For Dutch neonatal strains, a receiver operating characteristic (ROC) curve with serotype and five PPI markers showed an area under the curve (AUC) of 0.963 (95% confidence interval [CI] 0.935–0.99). For Taiwanese neonatal strains, serotype and four different PPI markers resulted in an ROC curve with an AUC of 0.894 (95% CI 0.826–0.963). PPI-specific and serological markers can distinguish local neonatal invasive GBS strains from colonizing ones. Apparently, there are clear regional differences in the GBS epidemiology and infection potential of clones.

Dynamic analysis with a fractional-order chaotic system for estimation of peripheral arterial disease in diabetic foot

Lower-extremity peripheral arterial disease (PAD) is caused by narrowing or occlusion of vessels in patients like type 2 diabetes mellitus, the elderly and smokers. Patients with PAD are mostly asymptomatic; typical early symptoms of this limb-threatening disorder are intermittent claudication and leg pain, suggesting the necessity for accurate diagnosis by invasive angiography and ankle-brachial pressure index. This index acts as a gold standard reference for PAD diagnosis and categorizes its severity into normal, low-grade and high-grade, with respective cut-off points of ≥0.9, 0.9–0.5 and <0.5. PAD can be assessed using photoplethysmography as a diagnostic screening tool, displaying changes in pulse transit time and shape, and dissimilarities of these changes between lower limbs. The present report proposed photoplethysmogram with fractional-order chaotic system to assess PAD in 14 diabetics and 11 healthy adults, with analysis of dynamic errors based on various butterfly motion patterns, and color relational analysis as classifier for pattern recognition. The results show that the classification of PAD severity among these testees was achieved with high accuracy and efficiency. This noninvasive methodology potentially provides timing and accessible feedback to patients with asymptomatic PAD and their physicians for further invasive diagnosis or strict management of risk factors to intervene in the disease progression.

Non-clostridial gas gangrene caused by Klebsiella pneumoniae: a case report.

A 45-y-old man was hospitalized due to pain and swelling of the right leg for 3 d. Bullae developed with gas formation involving multiple compartments of the entire limb 46 h later. Klebsiella pneumoniae was recovered from blood and surgical specimens. The patient died on Day 8 despite amputation and antibiotic therapy.A 45-y-old man was hospitalized due to pain and swelling of the right leg for 3 d. Bullae developed with gas formation involving multiple compartments of the entire limb 46 h later. Klebsiella pneumoniae was recovered from blood and surgical specimens. The patient died on Day 8 despite amputation and antibiotic therapy.

Case-Holding Investigation of a Cohort with Newly-Diagnosed Tuberculosis

Background: Tuberculosis (TB) is a historical and re-emergent infectious disease worldwide. Failure to control is often due to noncompliance with anti-TB treatment. With the prevalence of TB in Taiwan, a considerable level of noncompliance is highly suspected. The aim of study was to estimate both abscondence and non-compliance rate among a cohort of patients with newly diagnosed TB. Method: a historical cohort study was conducted at a private medical center serving two million people in Tainan county. In the year 2000, four hundred and two cases of definite or probable TB were notified to the health authority; 13% (53) absconded or died; the case holding rate was only 87% (349). Forty-five percent (157) was notified as definite diagnosis of tuberculosis; 55% as probable case, among them, 31% (59/192) was subsequently diagnosed with tuberculosis. Following the diagnosis of TB was made, 64%(139) stayed in the original hospital, and 27% shifted to the Chronic Diseases Control Center, Department of Health for completing the management; yet 3.2% (7) received no anti-TB treatment at all and refused to take any medications. Conclusion: There was approximately 13% of abscondence and 3.2% of non-compliance among the patients with newly diagnose TB; these patients can jeopardize the effectiveness of any TB control program, because case holding and compliance is the only method that can be expected to have short-term impact on transmission of TB. Control measures such as incentive and compulsory execution can be supplemented to enhance the effectiveness of TB control.