Molecular characterization and antibiotic resistance of Streptococcus dysgalactiae subspecies equisimilis isolated from patients with streptococcal toxic shock syndrome.

Streptococcal toxic shock syndrome (STSS) is a severe invasive infection characterized by the sudden onset of shock, multiorgan failure, and high mortality. Although STSS is mainly caused by Streptococcus pyogenes, group G streptococcus identified as S. dysgalactiae subsp. equisimilis (SDSE) causing STSS has also been reported; however, no study has analyzed >100 isolates of SDSE causing STSS. Therefore, we characterized the emm genotype of 173 SDSE isolates obtained from STSS patients in Japan during 2014-2016 and performed antimicrobial susceptibility testing using the broth microdilution method and emm gene typing. The predominant emm genotype was found to be stG6792, followed by stG485, stG245, stG10, stG6, and stG2078. These six genotypes constituted more than 75% of the STSS isolates. The proportion of each emm genotype in STSS isolates correlated with that in invasive isolates previously reported. We found that 16.2% of the isolates showed clindamycin resistance. The proportion of clindamycin-resistant SDSE isolates was significantly higher than that of S. pyogenes isolates. Thus, while treating STSS caused by SDSE, it is necessary to consider the possibility of clindamycin resistance and to ensure judicious use of the drug.

Increased prevalence of group A streptococcus isolates in streptococcal toxic shock syndrome cases in Japan from 2010 to 2012.

Streptococcal toxic shock syndrome (STSS) is a severe invasive infection characterized by the sudden onset of shock, multi-organ failure, and high mortality. In Japan, appropriate notification measures based on the Infectious Disease Control law are mandatory for cases of STSS caused by ß-haemolytic streptococcus. STSS is mainly caused by group A streptococcus (GAS). Although an average of 60-70 cases of GAS-induced STSS are reported annually, 143 cases were recorded in 2011. To determine the reason behind this marked increase, we characterized the emm genotype of 249 GAS isolates from STSS patients in Japan from 2010 to 2012 and performed antimicrobial susceptibility testing. The predominant genotype was found to be emm1, followed by emm89, emm12, emm28, emm3, and emm90. These six genotypes constituted more than 90% of the STSS isolates. The number of emm1, emm89, emm12, and emm28 isolates increased concomitantly with the increase in the total number of STSS cases. In particular, the number of mefA-positive emm1 isolates has escalated since 2011. Thus, the increase in the incidence of STSS can be attributed to an increase in the number of cases associated with specific genotypes.

Opening velocity, a novel parameter, for finger tapping test in patients with Parkinson's disease.

OBJECTIVES: A new system consisting of an accelerometer and touch sensor was developed to find objective parameters for the finger tapping (FT) test in patients with Parkinson's disease (PD). METHODS: We recruited sixteen patients with PD and thirty-two age-matched healthy volunteers (HVs). By using this new system, various parameters related to velocity, amplitude, rhythm and number in the FT test were measured in patients with PD and examined in comparison with those of HVs on the basis of the Unified Parkinson's Disease Rating Scale (UPDRS) FT score. RESULTS: The new system allowed us to measure fourteen parameters of FT movement very easily, and a radar chart showed obvious differences in most of these parameters between HVs and patients with PD. Principal component analysis showed that fourteen parameters were classified into three components: (1) both mean and standard deviation (SD) of both amplitude and velocity, (2) number of FT for 60s and mean FT interval, and (3) SD of FT interval. The first (velocity- and amplitude-related parameters) and third (rhythm-related parameters) components contributed to discrimination of PD from HVs. Maximum opening velocity (MoV) was the best of these parameters because of its sensitivity and association with the UPDRS FT score. CONCLUSIONS: A novel system for the FT test, which is compact, simple and efficient, has been developed. Velocity- and amplitude-related parameters were indicated to be valuable for evaluation of the FT test in patients with PD. In particular, we first propose that MoV is a novel marker for the FT test.

Distribution of emm genotypes among group A streptococcus isolates from patients with severe invasive streptococcal infections in Japan, 2001-2005.

We surveyed emm genotypes of group A streptococcus (GAS) isolates from patients with severe invasive streptococcal infections during 2001-2005 and compared their prevalence with that of the preceding 5 years. Genotype emm1 remained dominant throughout 2001 to 2005, but the frequency rate of this type decreased compared with the earlier period. Various other emm types have appeared in recent years indicating alterations in the prevalent strains causing severe invasive streptococcal infections. The cover of the new 26-valent GAS vaccine fell from 93.5% for genotypes of isolates from 1996-2000 to 81.8% in 2001-2005.

Tactile substitution system for transmitting a few words to a prosthetic hand user.

This paper describes an efficient system for transmitting a few words (verbal information) to a prosthetic hand user by using a two-channel electrotactile stimulation capable of generating apparent movements, which is applied to the upper arm area of the left hand via surface concentric electrodes. If the prosthetic hand user gets verbal information about interaction between the prosthesis and the environment, e.g., the prosthetic hand just touched a doorknob, he/she will be able to open or close the door even in the darkness, and also to handle an object on the top of a shelf out of his/her view. In this study, verbal information was provided regarding which finger touches the object (three states), and the fingers angle (two states). Consequently, six states of verbal information could be sent. We therefore designed five stimulation patterns (duration 600 - 800 ms) comprising several burst profiles in which each burst was composed of several pulses (interval of biphasic pulses, 2.85 ms) modulated in amplitude. The recognition experiments using 10 healthy subjects showed that the mean percentage of recognition was about 94% (standard deviation: 3.9). These results suggested the possible applicability of the proposed system to assist prosthetic hand users.

Sensory substitution system of two-channel electrotactile stimulation for transmitting verbal information.

We have aimed at developing a sensory substitution system for transmitting verbal information. In this work, we propose a basic two-channel electrotactile stimulation system and examine the usefulness of the system. The verbal information to be provided consists of two items: one is the object and another is the location (direction) of the object in the surrounding of the subject Three objects and three directions are utilized in this work. Each of the nine possibilities was transmitted to the subject as a skin stimulus consisting of two consecutive stimulation patterns; the first pattern represents the direction and the second the object. Stimulation pattern for each item was generated by two-channel voltage-pulse trains, which elicited a movement impression on the subject's skin. The electrical stimulus was delivered on the dorsal carpal area of the left hand. High percentage of recognition (average: 92%, standard deviation: 4.2) was obtained. Recognition percentages were improved by giving the subject a prior explanation about each stimulation pattern and increasing the stimulus intensity up to 95 % of the pain threshold.

Changing prevalent T serotypes and emm genotypes of Streptococcus pyogenes isolates from streptococcal toxic shock-like syndrome (TSLS) patients in Japan.

We surveyed T serotypes and emm genotypes of Streptococcus pyogenes isolates from streptococcal toxic shock-like syndrome (TSLS) patients. T1 (emm1) remained dominant through 1992 to 2000, but the dominant T3 (emm3.1) strains from 1992 to 1995 disappeared during 1996-2000. Strains of several emm genotypes emerged during 1996-2000, indicating alterations in the prevalent strains causing TSLS.

Sarcomere lengths of thick skeletal muscle specimens measured under an epi-illumination-type polarization microscope.

The purpose of this study was to measure sarcomere lengths of thick muscle fiber bundles at resting and at isometric tetanic contractions. We developed a novel measurement system using an epi-illumination-type polarization microscope and an image processing algorithm using an ellipse-type Gabor filter. Images with striation patterns of frog skeletal muscle were obtained by the microscope and the image processing algorithm. Individual lengths of 10 consecutive sarcomeres of a single muscle fiber were measured by gauging each width of the striation pattern, which was proved to be derived from striation structures of the single fiber by performing experiments using different polarization lights and different focus depths. At the resting state, each sarcomere length was identical at the fixed muscle length and in proportion to the length ranging over 91-123% of the natural length. Each sarcomere length was unchanged at the steady state during isometric tetanic contractions. Individual sarcomere lengths in the central part of the skeletal muscle were identical at resting and at isometric tetanic contractions even in the thick muscle fiber specimen.

[Epidemiological survey for hemolytic streptococci isolated from children in Tokyo].

During the 20-year period between 1979-1998, a total of 4,176 strains of hemolytic streptococci have been isolated from 20,118 healthy primary school children and little children in Tokyo Metropolitan (Tokubetsuku, Tama and Tosho). Culture of throat swabs every November and the following February during the 20-year period were made and serological grouping and typing for isolates were done by T agglutination method. The results were as follows. 1) Serological group of hemolytic streptococci isolated from children were 3,188 strains (76.3%) for isolates of group A out of total strains of 4,176, 569 strains (13.6%) for isolates group B, 63 strains (1.5%) for isolates of group C and 356 strains (8.5%) for isolates of group G. 2) The most dominant was T12 during 1979-1998, and other relatively frequent serotypes were T28, T1, T4, T6 in that order. These ranks of and the main epidemic serotypes showed a similar trend in the 3 areas. 3) The isolation rates of group A streptococci were 15.9% in Tokubetsuku, 17.1% in Tama and 14.9% in Tosho. The average of 3 areas were 15.8%. 4) The epidemic cases seemed to be caused by group A streptococci were 20 cases, their isolated serotype were 7 cases by T28, 5 cases by T12, 4 cases by T6, 2 cases by T4, each 1 case by T1 and T25. 5) A total of 2,927 strains of group A streptococci were examined for drug sensitivity. All strains were sensitive to beta-lactam group of antibiotics (benzylpenicillin and cephaloridine). Resistant (MIC > or = 25 micrograms/ml) to TC, CP and EM etc. were 740 strains (25.3%) in this study. The incidence of resistant strains were to TC 493 strains (66.6%) out of 740 strains, 81 strains (10.9%) for TC.CP, 72 strains (9.7%) for EM and 66 strains (8.9%) for TC.CP.EM.OL.LCM. TC resistant strains have not varied much through the whole period, but CP and EM resistant strains were very variable by year. Many resistant strains to TC were T4, to EM and multiple drug resistant were T12. 6) The rates of isolates of the same type of group A streptococci in school child individual during for the tests taken twice a year were 12.3%, indicating group A streptococci, according to the duration of the carrier state, seems to be a short period.

Biomimetic myoelectric hand with voluntary control of finger angle and compliance.

The purpose of this study was to develop a new type of myoelectrically controlled biomimetic prosthetic hand which has almost the same dynamics as that of the neuromuscular control system of the finger muscles, and in mechanical properties of the muscles and of the stretch reflex. One of the characteristic features of the neuromuscular control system in man is the increase in the compliance around the joint with decreasing activity of the muscle. Our prosthetic hand consisted of two surface EMG signal processing units, a digital servo system for a DC motor and 1 d.o.f. mechanical hand with three fingers. The dynamics of the neuromuscular control system including variation of the compliance around the joint was realized by using a position control system of the finger movement, force feedback and a variable gain which was modulated by the amplitude of IEMGs (rectified and smoothed EMG signals). EMG signals recorded from a pair of antagonistic muscles used to flex or to extend the wrist were used as control signals. It was shown that the finger angle and the compliance of the prosthetic hand could be controlled voluntarily with EMG signals, and that an amputee could grasp a soft object easily with the prosthetic hand. Utility of the biomimetic prosthetic hand was shown by executing myoelectric control experiments in one healthy subject and one amputee.

Relation between intrinsic viscoelasticity and activation level of the human finger muscle during voluntary isometric contraction.

The purpose of the present study was to isolate the length perturbation-evoked force attributed to intrinsic muscle viscoelasticity, and to investigate the relation between muscle viscoelasticity and the level of muscle activation during isometric contraction in five healthy male subjects. A small length perturbation (stretching or contraction) was applied to the flexor pollicis longus muscle while the subject maintained constant isometric force; the time courses of the length perturbation was found to be almost identical in all the experiments. The force (Fv) induced by the muscle viscoelasticity was calculated using the equation Fv = F - Fc - Fp over an interval of 35 ms after the onset of perturbation, where F is the measured force, Fc is the tonic isometric force before the onset of perturbation and Fp is the force at rest obtained from the same length perturbation. The force response attributed to the stretch reflex is not included during this interval. These experiments were repeated at varying levels of isometric force. An almost linear relationship was obtained between the muscle viscoelasticity-induced force and the tonic isometric force during both the stretching and contraction of the muscle, i.e. the intrinsic muscle viscoelasticity varied almost linearly with the level of isometric contraction.

[Human fibrinogen binding activities in culture supernates of group A streptococci. Streptococcal Diseases Study Group].

Fibrinogen binding activities in culture supernates of group A streptococci were detected by dot blot assay using horseradish peroxidase conjugated human fibrinogen. Various intensities in colored dots were seen in 63 of 70 strains isolated from pharyngitis patients in 1992. Strong binding activities in all of 16 strains were partially sensitive to trypsin digestion. The binding activities in the concentrated culture supernate of M-type 4 strain SS91 were analysed by SDS-PAGE and Western blotting. Intense colored bands and faint ones were seen in the position corresponding to 89K, 66K, 59K, 49K, 42KDa and 77K, 53K, 51K, 44KDa, respectively. Only one band at 42KDa remained after trypsin digestion.

[Antibiotic sensitivity and serotypes of group A hemolytic streptococci isolated from clinical specimens and healthy pupils in Japan, 1986-1988].

As an epidemiological survey for streptococcal infection, antibiotic sensitivity test and T-serotyping were made on 2,735 strains of group A hemolytic streptococci isolated from clinical specimens and healthy pupils between 1986 through 1988 in Japan. Most dominant serotype in clinical isolates was T-4 (26.8%) and it was followed T-12 (25.5%), T-1 (11.2%) and T-3 (8.5%), on the other hand, dominant serotypes of the isolates from healthy pupils were T-12 (30.4%), T-1 (19.3%), T-4 (15.3%) and T-28 (13.4%). All of the isolates tested were sensitive to the beta-lactam antibiotics which was found as same as consequence of the previous surveys. However 36.4% to tetracycline, 2.1% to chloramphenicol and 1.4% to oleandomycin of the clinical isolates were resistant. Similarly, 16.2% to tetracycline, 2.3% to chloramphenicol 1.7% to oleandomycin, of the isolates from healthy pupils were resistant. Multi-resistant strains were found 1.4% in clinical isolates and 1.7% in the isolates from healthy pupils. Relation between distribution of multiresistant strain and T-serotypes was found. In T-12, multiresistant strains were encountered at a relatively high rate compared with other serotypes, representing 3.5% in clinical isolates and 5.6% in the isolates from healthy pupils. However this tendency was decreased than previous surveys, while incidence of tetracycline resistant strains in T-4 remained at high level, representing about 94% as same as in the past.