PspA Family Distribution,Antimicrobial Resistance and Serotype of Streptococcus pneumoniae Isolated from Upper Respiratory Tract Infections in Japan

Background

The protection against pneumococcal infections provided by currently available pneumococcal polysaccharide conjugate vaccines are restricted to the limited number of the serotypes included in the vaccine. In the present study, we evaluated the distribution of the pneumococcal capsular type and surface protein A (PspA) family of pneumococcal isolates from upper respiratory tract infections in Japan.

Methods

A total of 251 S. pneumoniae isolates from patients seeking treatment for upper respiratory tract infections were characterized for PspA family, antibiotic resistance and capsular type.

Results

Among the 251 pneumococci studied, the majority (49.4%) was identified as belonging to PspA family 2, while most of the remaining isolates (44.6%) belonged to family 1. There were no significant differences between the distributions of PspA1 versus PspA2 isolates based on the age or gender of the patient, source of the isolates or the isolates’ susceptibilities to penicillin G. In contrast, the frequency of the mefA gene presence and of serotypes 15B and 19F were statistically more common among PspA2 strains.

Conclusion

The vast majority of pneumococci isolated from the middle ear fluids, nasal discharges/sinus aspirates or pharyngeal secretions represented PspA families 1 and 2. Capsular serotypes were generally not exclusively associated with certain PspA families, although some capsular types showed a much higher proportion of either PspA1 or PspA2. A PspA-containing vaccine would potentially provide high coverage against pneumococcal infectious diseases because it would be cross-protective versus invasive disease with the majority of pneumococci infecting children and adults.     

Molecular Characterization of the Recently Emerged Poultry Pathogen Ornithobacterium rhinotracheale by Multilocus Sequence Typing

Ornithobacterium rhinotracheale (ORT) is an economically important bacterial pathogen of turkeys and chickens worldwide. Since its first detection, a variety of typing methods have been used to gain basic knowledge about the bacterial population structure, an issue that still needs to be addressed. Serological characterization revealed at least 18 different serotypes (A-R) with ORT of serotype A to be predominate among poultry. This study aimed to establish a multilocus sequence typing (MLST) scheme for ORT that could easily be used by other laboratories and allows for worldwide comparison of sequence data. For this purpose, 87 ORT strains from different poultry hosts, geographical origins, years of isolation and serotypes were included in the analysis to identify correlations. Fourteen different sequence types (ST) were found. The most common ST1 was identified in 40 ORT strains from turkeys and chickens on 4 continents and in 3 different European countries. Together with ST9, both STs represented over three quarters (77%) of ORT strains used in the MLST analysis and included strains of frequently cross-reacting ORT serotypes A, E and I. Nine STs were only represented by one ORT strain and might indicate possible avian host, disease or serotype-specific relationships. In contrast, discrepancies between serotype and phylogenetic relatedness were clearly demonstrated by ORT strains that belonged to identical serotypes but differed in their ST. The overall identified low genetic diversity among strains isolated from turkeys and chickens independent of host and geographical origins suggests that ORT has only recently been introduced into domestic poultry and dispersed worldwide.     

2009年云南省边境地区健康儿童肠道病毒测序定型和ECHO7、ECHO13病毒的基因特征分析

了解2009年缅甸入境健康儿童和云南省口岸地区健康儿童肠道病毒(enterovirus,EV)带毒情况并对埃柯病毒7型(ECHO7)和埃柯病毒13型(ECHO13)的基因特征进行了描述。采集9个边境口岸小于15岁的健康儿童粪便标本271份,进行病毒分离和基因测序定型。271份便标本中共检测到EV30株(带毒率为11.1%),其中脊髓灰质炎病毒(poliovirus,PV)6株(阳性率2.8%),均为疫苗株,未发现脊灰野病毒;检测到非脊灰病毒(NPV)24株(阳性率8.9%)。经VP1区核苷酸序列测定,24株NPV全部为人类肠道病毒B组(HEV-B,6个血清型),其中13株为埃柯病毒7型(echovirus 7,ECHO7,占54.17%),5株为ECHO13(占20.83%)。未分离到HEV-A组,HEV-C组和HEV-D组病毒。2009年缅甸入境健康儿童和云南省口岸地区健康儿童中肠道病毒携带率较高,且均为HEV-B组病毒,其中主要型别为ECHO7和ECHO13,这两种病毒存在基因多样性特点(即存在不同的基因型)。     

Serotypes and antibiotic resistance of Verotoxigenic (VTEC) and Necrotizing (NTEC) Escherichia coli strains isolated from calves with diarrhoea

Serotypes and antibiotic resistance of 51 Verotoxigenic (VTEC) and 33 Necrotizing (NTEC) bovine Escherichia coli strains were determined and compared with those shown by 205 non-VTEC non-NTEC strains isolated from the same batch of calves. E. coli untypable for O-antigen represented 47% of the VTEC, 12% of the NTEC and 8.8% of the non-VTEC non-NTEC. Typable VTEC belonged to serotypes 02:K?, 0103:K-, 0104:K?, 0128:K?, 0153:K- and O157:K-:H7, whereas typable NTEC were of serotypes 08:K87, 015:K14, 015:K-, 054:K?, 076:K-, 078:K(80), 088:K?, 0123:K-, 0139:K- and 0153:K-. Non-VTEC non-NTEC showed a wide variety of serotypes which were generally unrelated to those found in VTEC and NTEC. VTEC were resistant to antibiotics at higher rates than NTEC and non-VTEC non-NTEC, and showed also the highest multidrug-resistant pattern. Our results show that bovine VTEC strains belonged to O-groups usually found in human VTEC causing sporadic diarrhoea, haemorrhagic colitis and/or haemolytic uraemic syndrome, such as 02, 0103, 0104, 0153 and especially 0128 and O157. In contrast, bovine NTEC strains belonged to serotypes different from those previously found in necrotizing E. coli strains of human origin.     

Streptococcus pneumoniae serotypes in children with chronic inflammatory diseases of the respiratory organs

During the 7-year period of observation (1982-1988) the serotypes of 276 pneumococcal strains isolated from children with chronic bronchopulmonary diseases were studied. Among the serotypes of pneumococci under study, serotypes 6, 19 and 15 held the leading place and included a half of all typed pneumococci. Dynamic observation on the serotype composition of pneumococci revealed periodic fluctuations in the occurrence of some types/groups. The regional analysis of different serotypes of pneumococci showed the common occurrence of serogroups 6 and 19, as well as some regional features in the circulation of serotypes 6, 10, 3 and rarely occurring serotypes. The study revealed that any new exacerbation of the chronic bronchopulmonary process is caused by pneumococci of some other serotype. Pneumococcal strains, resistant (3.4%) and sensitive (1.8%) to penicillin, were detected; most of them belonged to serogroup 19.     

An adhesive factor found in strains ofEscherichia coli belonging to the traditional infantile enteropathogenic serotypes

Escherichia coli strains isolated from outbreaks of diarrheal disease were tested for the presence of adhesive factors. Fifty-one of these strains belonged to traditional infantile entero-pathogenic serotypes (EPEC) and 17 belonged to other serotypes. None of these strains were enterotoxigenic and none possessed colonization factors CFA/I or CFA/II, which have been described among strains of enterotoxigenicE. coli (ETEC). EnterotoxigenicE. coli strains from patients with diarrhea and strains which were neither EPEC nor ETEC from subjects without diarrhea were also examined. By means of a tissue culture technique using HEp-2 cells, a new adhesive factor was found to occur with greater frequency in EPEC strains. The adhesive factor was found less frequently in the other groups ofE. coli studied. It was distinct from type 1 pili and was not inhibited by the presence ofD-mannose.     

Pneumococcal serotypes in various diseases of children

The serotyping of pneumococci isolated from different material obtained from children aged 0 to 11 years was carried out. Out of 156 patients with different diseases, hospitalized in two clinics in Moscow during February-May 1983, pneumococci were isolated from 67 patients (43%). The isolated pneumococcal strains belonged to 11 serotypes. Pneumococci of serotypes 3, 6, 9 and 19 were shown to occur most frequently in different diseases and constituted 50% of the isolated strains. The inoculation of the material by the quantitative method permitted the authors to find out the role of pneumococci as the etiological factor in the pathogenesis of some diseases. A certain dependence of diversity in the types of isolated pneumococci on the age of sick children was noted. Almost all isolated strains were found to be sensitive to penicillin, ampicillin and benzylpenicillin. But a few individual strains were sensitive only to one of these antibiotics. The data on some biological properties of pneumococci cultivated on solid culture media are presented.     

Diversity of staphylocoagulase and identification of novel variants of staphylocoagulase gene in Staphylococcus aureus

Staphylocoagulase (SC) is a major phenotypic determinant of Staphylococcus aureus. Serotype of SC (coagulase type) is used as an epidemiological marker and 10 types (I-X) have been discriminated so far. To clarify genetic diversity of SC within a single and among different serotype(s), we determined approximately 1500 bp-nucleotide sequences of SC gene encoding D1, D2, and central regions (N-terminal half and central regions of SC; SC(NC)) for a total of 33 S. aureus strains comprising two to three strains from individual coagulase types (I-VIII, X) and 10 strains which were not determined as previously known SC serotypes (ND-strains). Amino acid sequence identities of SC(NC) among strains with a single coagulase type of II, III, IV, V, VI and X were extremely high (more than 99%), whereas lower identity (56-87%) was observed among different types. In contrast, within a single coagulase type of I, VII, or VIII, sequence divergence was found (lowest identity; 82%). SC(NC) sequences from the ND-strains were discriminated into two genetic groups with an identity of 71% to each other (tentatively assigned to genotypes [XI] and [XII]), and exhibited less than 86% sequence identities to those of most known coagulase types. All the types [XI] and [XII] strains were methicillin susceptible and belonged to different sequence types from those of coagulase types I-X strains reported so far by multilocus sequence typing. These findings indicated genetic heterogeneity of SC in coagulase types I, VII, and VIII strains, and the presence of two novel SC genotypes related to antigenicity of SC serotypes.     

Genetic diversity of heat-labile toxin expressed by enterotoxigenic Escherichia coli strains isolated from humans

The natural diversity of the elt operons, encoding the heat-labile toxin LT-I (LT), carried by enterotoxigenic Escherichia coli (ETEC) strains isolated from humans was investigated. For many years, LT was supposed to be represented by a rather conserved toxin, and one derivative, produced by the reference H10407 strain, was intensively studied either as a virulence factor or as a vaccine adjuvant. Amplicons encompassing the two LT-encoding genes (eltA and eltB) of 51 human-derived ETEC strains, either LT(+) (25 strains) only or LT(+)/ST(+) (26 strains), isolated from asymptomatic (24 strains) or diarrheic (27 strains) subjects, were subjected to restriction fragment length polymorphism (RFLP) analysis and DNA sequencing. Seven polymorphic RFLP types of the H10407 strain were detected with six (BsaI, DdeI, HhaI, HincII, HphI, and MspI) restriction enzymes. Additionally, the single-nucleotide polymorphic analysis revealed 50 base changes in the elt operon, including 21 polymorphic sites at eltA and 9 at eltB. Based on the deduced amino acid sequences, 16 LT types were identified, including LT1, expressed by the H10407 strain and 23 other strains belonging to seven different serotypes, and LT2, expressed by 11 strains of six different serotypes. In vitro experiments carried out with purified toxins indicated that no significant differences in GM1-binding affinity could be detected among LT1, LT2, and LT4. However, LT4, but not other toxin types, showed reduced toxic activities measured either in vitro with cultured cells (Y-1 cells) or in vivo in rabbit ligated ileal loops. Collectively, these results indicate that the natural diversity of LTs produced by wild-type ETEC strains isolated from human hosts is considerably larger than previously assumed and may impact the pathogeneses of the strains and the epidemiology of the disease.     

Identification of two new intimin types in atypical enteropathogenic Escherichia coli.

Stool specimens of patients with diarrhea or other gastrointestinal alterations who were admitted to Xeral-Calde Hospital (Lugo, Spain) were analyzed for the prevalence of typical and atypical enteropathogenic Escherichia coli (EPEC). Atypical EPEC strains (eae+ bfp-) were detected in 105 (5.2%) of 2015 patients, whereas typical EPEC strains (eae+ bfp+) were identified in only five (0.2%) patients. Atypical EPEC strains were (after Salmonella) the second most frequently recovered enteropathogenic bacteria. In this study, 110 EPEC strains were characterized. The strains belonged to 43 O serogroups and 69 O:H serotypes, including 44 new serotypes not previously reported among human EPEC. However, 29% were of one of three serogroups (O26, O51, and O145) and 33% belonged to eight serotypes (O10:H-, O26:H11, O26:H-, O51:H49, O123:H19, O128:H2, O145:H28, and O145:H-). Only 14 (13%) could be assigned to classical EPEC serotypes. Fifteen intimin types, namely, alpha1 (6 strains), alpha2 (4 strains), beta1 (34 strains), xiR/b2 (6 strains), gamma1 (13 strains), gamma2/q (16 strains), delta/k (5 strains), epsilon1 (9 strains), nuR/e2 (5 strains), zeta (6 strains), iota1 (1 strain), muR/iota2 (1 strain), nuB (1 strain), xiB (1 strain), and o (2 strains), were detected among the 110 EPEC strains, but none of the strains was positive for intimin types mu1, mu2, lambda, or muB. In addition, in atypical EPEC strains of serotypes O10:H-, O84:H-, and O129:H-, two new intimin genes (eae-nuB and eae-o) were identified. These genes showed less than 95% nucleotide sequence identity with existing intimin types. Phylogenetic analysis revealed six groups of closely related intimin genes: (i) alpha1, alpha2, zeta, nuB, and o; (ii) iota1 and muR/iota2; (iii) beta1, xiR/beta2B, delta/beta2O, and kappa; (iv) epsilon1, xiB, eta1,eta2, and nuR/epsilon2; (v) gamma1, muB, gamma2, and theta; and (vi) lambda. These results indicate that atypical EPEC strains belonging to large number of serotypes and with different intimin types might be frequently isolated from human clinical stool samples in Spain.     

Serotypes among Neisseria meningitidis serogroups B and C strains isolated in Canada

Antisera made to prototype serogroup B strains of Neisseria meningitidis were used to serotype, by agar gel double diffusion, 262 meningococcal serogroups B and C strains isolated in Canada. The strains included 93 from patients and 169 from carriers. Serotype 2 was associated with 39 of 75 (52%) of group B strains and 14 of 18 (77.8%) of group C strains isolated from patients. The group B strains were mainly (87.2%) serotype 2b, while the majority (92.2%) of group C strains was serotype 2a. Other serotypes (including a new provisional serotype) represented 25.3 and 5.5% of groups B and C strains, respectively. The new serotype accounted for 13% of the group B strains. Approximately 23% of the strains isolated from patients were nontypable. The distribution of serotype 2, nontype 2 (other serotypes), and nontypable strains isolated from carriers was 2.1, 36.6, and 61.3%, respectively, for group B meningococci and 22.2, 29.6, and 48.25, respectively, for group C meningococci. Serotype 11 was the most prominent of the strains isolated from carriers. Approximately 7% of all the strains were multiple serotypes. Serotype 2 is an important virulence marker associated with meningococcal groups B and C disease in Canada, with serotypes 2a and 2b being markedly associated with groups C and B meningococcal disease, respectively.     

Evolution of poliovirus since introduction of attenuated vaccine.

Genetic marker tests were performed on 997 strains of poliovirus isolated from patients with neurological disease and from healthy people in England and Wales. Before the introduction of live attenuated vaccine most strains could multiply at raised temperatures. Now, however, many strains isolated from cases of poliomyelitis or from healthy persons with no known contact with vaccine cannot grow above 37 degrees C, and in this respect resemble the vaccine strains. The three serotypes are also much more evenly represented. Hence probably to a limited extent the vaccine-like strains have established themselves in the community.     

Population pattern of pneumococci with lower susceptibility to penicillin and prospects of antipneumococcal vaccination to control antibiotic resistance distribution

Large-scale antipneumococcal vaccination is followed by changes in the serotype composition and level of antibiotic resistance in pneumococci. The aim of the study was to evaluate the serotype composition and population pattern of pneumococci with lower susceptibility to penicillin before large-scale antipneumococcal vaccination. Among 260 Streptococcus pneumoniae strains isolated in the Russian Federation within 2003-2007, serotypes 23F (37.2%) and 19F (13.9%) were the most frequent ones. 19.3% of the isolates belonged to serogroup 6, 3.6% of the isolates each belonged to serotype 3 and serogroup 18, 4.9% of the isolates belonged to serotype 14 and 2.2% of the isolates belonged to serotype 19A. 66.8% of the isolates belonged to serotypes of the 7-valent conjugated pneumococcal vaccine, 67.3 and 82.1% of the isolates belonged to the 10- and 13-valent conjugated pneumococcal vaccines respectively. The isolates with lower susceptibility to penicillin were characterized by significant clonality and 56.9% of them belonged to 4 global clonal complexes (CC81, CC156, CC320 and CC315). Inclusion of the conjugated antipneumococcal vaccine to the National Vaccination Time-Table of the Russian Federation could promote lower levels of antibiotic resistance in pneumococci.     

Biochemical typing as a method of differentiating group B streptococcus]

In epidemiological studies on the group B streptococcus the serological typing is used. The paper present the results of a study on usefulness of biochemical typing for differentiation of the group B streptococcus. For that purpose, 210 strains descended from colonized infants and pregnant women were put to typing with both of mentioned methods. We showed that each of the method distinguishes similar number of biotypes and serotypes. However, ought to be marked that significant number of strains (93.8%) belonged to the three out of eight biochemical types. Similar results were achieved in serological typing, three of the most numerous serotypes contained 81.4% strains. Analysis of the relationship between serological and biochemical types did not reveal statistical association because the strains belonged to various serotypes. Obtained results show that both methods of typing--biochemical and serological, have similar value in differentiation of the strains. The method of biochemical typing is quite simple and can be used in laboratory conditions.     

Is Bordetella pertussis clonal?

OBJECTIVE--To establish whether Bordetella pertussis is essentially clonal. DESIGN--Analysis of restriction fragments of XbaI digests of DNA from clinical and control isolates of B pertussis by pulse field gel electrophoresis. MATERIALS--105 isolates of B pertussis: 67 clinical isolates from throughout the United Kingdom and 23 from Germany (collected during the previous 18 months); vaccine strains 2991 and 3700; and 13 control isolates from Manchester University''s culture collection. MAIN OUTCOME MEASURES--Frequency of DNA types according to country of origin and classical serotyping. RESULTS--17 DNA types were identified on the basis of the variation in 11 fragments, banding at 200-412 kilobases; 15 types were found in the clinical and control isolates from the United Kingdom and seven in those from Germany. There was no correlation with serotype. DNA type 1 was the commonest overall (22/105 strains, 22%), predominating in serotypes 1,2 and 1,2,3 and including the vaccine strains but not the isolates from Germany. CONCLUSIONS--Current infections due to B pertussis are not caused by a clonal pathogen as multiple strains are circulating in a given population at one time. There is also considerable epidemiological variation in the pathogen population between countries. These findings may have implications for the design of acellular vaccines.     

Serotype distribution of Streptococcus pneumoniae in north-western Greece and implications for a vaccination programme

Serotypes and antibiotic sensitivities were determined for 338 strains of Streptococcus pneumoniae from children of north-western Greece with invasive pneumococcal disease (IPD), acute otitis media (AOM) and nasopharyngeal carriage. The most common serotypes among the isolates from IPD were 14 and 19F, while 3, 19F, 9V and 14 were the major cause of AOM. In these groups, the heptavalent conjugate vaccine for pneumococci (7vPCV) seems to cover 90.5% of the serotypes isolated from children less than 2 years old. Serotypes 23F and 6B were the most prevalent in carrier strains. Overall, 23.7% of the isolates were penicillin nonsusceptible (PNS), 97% were fully susceptible to cefotaxime, 29% were resistant to erythromycin, 11.2% to co-trimoxazole and 1.2% to clindamycin.     

Incidence of non-cholera vibrios in Hungary.

In the period 1971 to 1976, 200 non-cholera vibrio (NCV) strains were isolated in Hungary; 18 of the cultures were derived from 34 729 faecal and 182 from 237 surface water samples. Ninety-two strains belonged to the Heiberg-Smith group I and 108 to group II. Two strains failed to give the string test and 3 were pteridine resistant. The strains were classified into 48 serotypes according to Smith's system. Faecal NCV strains belonged to serotypes 46 and 328; these serotypes did not occur in water. Of the 18 faecal strains 13 were isolated from 18 048 persons who had travelled in cholera-infected areas, and 5 strains from persons who had never left Hungary (2 from 4559 patients with diarrhoea and 3 from 6061 healthy individuals). These data indicate that although NCV are present in the environment, they play an insignificant role in enteric infections in Hungary.     

Serotyping of Dutch Staphylococcus aureus strains from carriage and infection

International epidemiological studies have shown that clinical isolates of Staphylococcus aureus are usually capsulated with either type 5 or 8 capsular polysaccharides (CPs). Because all noncapsulated strains were found to be cross-reactive with polysaccharide 336 (336PS) antibodies, the noncapsulated strains were denoted as type 336PS. The capsular types of 162 Dutch methicillin-susceptible S. aureus strains derived from individuals living in the Rotterdam area were determined. The serotype distribution was 28.4% serotype 5, 53.7% type 8, and 17.9% type 336PS. Serotyping was in agreement with genotyping by amplified fragment length polymorphism (AFLP) and multi locus sequence typing (MLST). Among 49 nasal carriage isolates from healthy children 24.5% belonged to serotype 5, 67.3% were type 8 and 8.2% were type 336PS. For 28 adult patients on chronic ambulatory peritoneal dialysis (CAPD) the serotype incidences among carriage isolates obtained from the nose, catheter exit-site, and abdominal skin were 45.1%, 41.2% and 13.7%, respectively. Among S. aureus strains deriving from blood cultures, the serotype incidences were 17.7% serotype 5, 53.2% type 8, and 29.0% type 336PS. Apparently, type 336PS strains are more prevalent (P=0.017) among bacteraemia isolates as compared with the nasal carriage isolates obtained from healthy children and CAPD patients. In conclusion, all Dutch S. aureus isolates belonged to types 5, 8, or 336PS, which is in agreement with data from other countries. Thus, addition of the 336PS conjugate to a type 5- and type 8-CP protein conjugate vaccine would significantly extend the vaccine coverage.     

2012–2015年江淮地区猪丹毒杆菌分离株血清型、spaA基因遗传进化及PFGE基因型分析

【目的】了解2012–2015年江淮地区猪丹毒杆菌分离株血清型分布、spaA基因遗传进化关系和基因分型特征。【方法】收集临床分离鉴定的42株猪丹毒杆菌,应用琼脂扩散沉淀实验、PCR扩增和序列分析技术、脉冲场凝胶电泳分型技术(PFGE)分别测定分离株的血清型、spaA基因遗传变异性及PFGE基因型。【结果】42株猪丹毒杆菌分离株血清型均为1a型;spaA基因与猪丹毒杆菌国内外参考株核苷酸序列相似性为98.5%–100%,分离株在第609 bp处出现T突变为G、769 bp处C突变为A,对应的氨基酸第203位Ile突变为Met、第257位Leu突变为Ile,为Met-203、Ile-257型;分离株形成8个PFGE基因型,相似度达88.8%–100%,优势基因型为ER2 (54.8%),弱毒疫苗G4T10和GC42株独立为同一个基因型。【结论】江淮地区致病猪丹毒杆菌流行血清型为1a型,spaA基因相似性高,分离株变异小、源于同一克隆系,Met-203、Ile-257型菌株致病力强,是江淮地区猪丹毒发生与流行的主要致病菌型。     

Endemic occurrence of infections by multidrug-resistant Escherichia coli of four unique serotypes in the elderly population of Israel

During a period of four years, multidrug-resistant Escherichia coli of particular serotypes have been isolated from 255 elderly (>65 years) patients from four hospitals in central Israel. 83% of the isolates belonged to one of four predominant serotypes (O153:H31, O101:H-, O2:H42, and O102:H6). All isolates were producers of extended spectrum beta-lactamases and resistant to ciprofloxacin. To our knowledge, the involved serotypes have hitherto not been reported as etiological agents of extraintestinal human infections (MEDLINE). Pulsed-field gel electrophoresis of isolates from one of the most frequent serotypes indicated a clonal relationship between them. Further investigation of these strains and analysis of their virulence factors may help to confine their spread.