Objective: To identify a suspected clustered Typhoid fever by whole genome sequencing(WGS) and pulsed field gel electrophoresis (PFGE) subtyping. Methods: The nature of the epidemic was determined by combination of subtyping results of isolates and epidemiological information. Results: Five S. typhimurium isolates showed identical PFGE patterns and almost the same whole genome sequence. Epidemiological survey showed that five cases had dined in the same restaurant on the same day. Conclusion: Combined with the longest incubation period of typhoid fever, molecular subtyping of pathogenic bacteria and the field epidemiological survey, it can be preliminarily determined that the five cases have common infection sources.
Electrophoresis, Gel, Pulsed-Field ; Epidemics ; Humans ; Typhoid Fever/microbiology*

We report a case of hemophagocytic syndrome (HPS) secondary to brucellosis, in which typhoidal cells were found in bone marrow, suggesting typhoidal cells present not only in Salmonella typhi infections but also in other bacterial infections. Typhoidal cells in bone marrow can be used to quickly identify the presence of bacterial infection pending the results of bone marrow and/or blood cultures.
Female ; Humans ; Typhoid Fever/microbiology* ; Lymphohistiocytosis, Hemophagocytic/etiology* ; Brucellosis/complications*

The authors analysed bone marrow findings of sixteen cases of culture proven typhoid fever to reveal the pathologic changes according to the disease stage. The most frequent finding was chronic granulomatous inflammation (eight cases). Infection (bacteria) associated hemophagocytic syndrome (four cases), reactive marrow (two cases), and non specific findings (two cases) were also encountered. Granulocytic hyperplasia with hemophagocytosis appeared at the early stage and was followed by infection (bacteria) associated hemophagocytosis and granuloma in proliferative stage. In lysis (late) stage, granulomatous inflammation was noted. However, resolution of granulomatous inflammation was not distinct. Some nuclear debris and phagocytosis were remarkable in well-formed granulomas. Thrombocytopenia was the most remarkable peripheral blood finding at the time of biopsy. Anemia, leukopenia, and pancytopenia were also observed in descending order.
Adult ; Bone Marrow/microbiology/*pathology ; Female ; Humans ; Male ; Middle Aged ; Salmonella typhi/isolation & purification ; Thrombocytopenia/pathology ; Typhoid Fever/microbiology/*pathology

Seventy-seven Streptococcus pyogenes strains isolated of children of three elementary schools located in Kangwon-do in spring, 1992 were serotyped with M, opacity factor (OF) and T typing antisera. In the M/OF typing results, M-78 (46.8%) and M-28 (22.1%) were most frequently encountered, while M-4 (6.5%), M-12 (5.2%), M-3 (1.3%), M-5 (1.3%) and M-6 (1.3%) were rarely observed. Twelve strains (15.6%) were not typable with M or OF typing system. In the T typing results, T-11 (35.1%) and T-28 (27.3%) were most common. We were able to identify 77.9% of S. pyogenes strains by T typing, 94.8% with T typing and OF typing. With the addition of M typing, 97.4% were typable. Through the serotypings, we could know the basic distribution of serotypes of S. pyogenes of healthy children which could be comparable to those of rheumatic fever, poststreptococcal glomerulonephritis and other severe streptococcal disease.
Adolescent ; Bacterial Typing Techniques ; Child ; Female ; Humans ; Korea ; Male ; Pharynx/microbiology ; Rheumatic Fever/microbiology ; Serotyping ; Streptococcus pyogenes/*classification/isolation & purification

OBJECTIVETo study the existence of natural foci of Spotted Fever in Ninghua, Fujian province.

METHODSUsing DNA polymerase chain reaction and restriction endonuclease fragment length polymorphism analysis (PCR/RFLP) to detect spotted fever group rickettsiae (SFGR) in ticks and rodents.

RESULTSIt was found that H. wellingtoni, H. yeni, and Dermacentor auratus were infected with Rickettsia sibirica; the DNA fragments were cloned, the PCR products from isolated strain NH-97 were antigenically and genotypically identical to Rickettsia sibirica. Rattus flavipectus were found infected with R. conorii. One of the sequeuce analysis showed that the DNA sequence was different from other SFGR and close to R. japanic.

CONCLUSIONNatural foci of R. sibirica, R. sibrica, R. japanic and R.conorii are found in Ninghua, Fujian province of China.

Animals ; Boutonneuse Fever ; microbiology ; China ; Polymerase Chain Reaction ; methods ; Polymorphism, Restriction Fragment Length ; Rats ; Rickettsia ; genetics ; isolation & purification ; Rodentia ; microbiology ; Ticks ; microbiology

Humans ; Pharyngitis ; complications ; microbiology ; Rheumatic Fever ; etiology ; Streptococcal Infections ; complications ; Streptococcus pyogenes

Objective: To understand the epidemiological and molecular characteristics of typhoid and paratyphoid in China from 2009 to 2013, and provide evidence for the prevention and control of typhoid and paratyphoid, the development and improvement of surveillance strategies. Methods: Epidemiological analysis was conducted on the incidence data of typhoid and paratyphoid, and related public health emergencies in China during 2009-2013. Pathogen isolation and culture, serologic test were conducted for the typhoid and paratyphoid cases from 13 national surveillance sites. The isolates were subjected to antimicrobial susceptibility testing. Pulsed-field gel electrophoresis (PFGE) was performed for the molecular typing of these isolates. Results: The average incidence of typhoid and paratyphoid in China during this period was 1.03/100 000. The reported case number and incidence decreased with year. The provinces reporting high case numbers were Yunnan, Guizhou, Guangxi, Hunan, Zhejiang, Guangdong and Xinjiang. The incidence of age group 0-4 years was highest. The proportion of farmers and children outside child care settings showed an increasing tendency over time. The annual incidence peak was during July-August. Twenty five outbreaks occurred during 2009-2013. The results of pathogen isolation and culture showed that the positive rate was 3.00% (940/31 322), among the positive isolates, the proportion of Salmonella paratyphi A accounted for higher proportion (68.19%, 641/940) compared with Salmonella typhi (31.60%, 297/940). The drug resistances of Salmonella typhi and Salmonella paratyphi varied, but their resistances to nalidixic acid were highest (50.22% and 85.33%) respectively. A certain amount of Salmonella typhi isolates showed the resistance to the 3rd generation cephalosporins. PFGE analysis showed divergent patterns of Salmonella typhi compared with limited patterns of Salmonella paratyphi A. Conclusion: The epidemic level of typhoid and paratyphoid in China was relatively low, but the outbreak occurred occasionally. It is necessary to enhance the laboratory-based surveillance, particularly the capability of etiological diagnosis, outbreak investigation, response and antibiotic resistance monitoring, and conduct risk factor investigation in provinces with high incidences in recent years.
Child ; Child, Preschool ; China/epidemiology* ; Disease Outbreaks ; Drug Resistance, Bacterial/genetics* ; Electrophoresis, Gel, Pulsed-Field ; Epidemics ; Farmers ; Humans ; Incidence ; Infant ; Molecular Typing ; Paratyphoid Fever/microbiology* ; Population Surveillance ; Salmonella paratyphi A/isolation & purification* ; Salmonella typhi/isolation & purification* ; Typhoid Fever/microbiology*

OBJECTIVETo explore the existence of spotted fever group Rickettsiae (SFGR) in Guangdong province.

METHODSSera were tested to find the SFGR in population and host animals. The target samples were screened by polymerase chain reaction (PCR), and Rickettsiae was isolated with embryonated hen eggs and identified by serological tests.

RESULTSEight hundred and sixty people in natural condition and 321 of mice were determined. The mean positive rate of healthy population was 3.84%. To compare results among elected places, Fisher's exact test was applied. The difference was suggestive (P < 0.01), and there was no significant difference between mountain and plain areas. There was also no significant difference between mountain and plain areas (P > 0.05). Positive rate of mice was 4.67%, with Rattus fulvescens, Rattus edwardsi, Bandicota indica 11.59%, 12.90%, 3.13% respectively. It was the first time that SFGR antibodies in Rattus fulvescens, Rattus edwardsi, Bandicota indica were reported. A total number of 321 mice spleens and 394 ticks from the surface of mice body were collected. Two strains of SFGR, GDFK58-2000 and GDFK59-2000, were isolated in the ticks from the body surface of 2 Rattus fulvescens. They were identified as Rickettsia sibirica by serological tests. Five hundred thirty-three bp OmpA gene fragments of the two strains were cloned and sequenced. Compared with other relevant strains in Genbank, the rates of homology of nucleotide sequences of GDFK58-2000 and GDFK59-2000 and other Rickettsia sibirica strains were from 99.6% to 100%, and the homology of amino acid speculated was 100%.

CONCLUSIONIt has been proved that epidemic areas of north Asia tick-transmitted SFGR, did exist in Guangdong province confirmed by hostanimals, transmission vectors and aetiology.

Adolescent ; Adult ; Aged ; Animals ; Child ; China ; epidemiology ; Disease Reservoirs ; Female ; Humans ; Male ; Mice ; Middle Aged ; Rats ; Rickettsia rickettsii ; classification ; genetics ; isolation & purification ; Rocky Mountain Spotted Fever ; epidemiology ; microbiology ; Rodentia ; microbiology ; Sequence Homology, Amino Acid ; Ticks ; microbiology

Objective: To analyze the characteristics of super-antigen (SAg) of group A Streptococcus pyogenes (GAS), isolated from patients with scarlet fever or pharyngeal infections in Beijing between 2015-2017. Methods: Throat swab specimens from patients with scarlet fever or pharyngeal infections were collected and tested for GAS. Eleven currently known SAg genes including SpeA, speC, speG, speH, speI, speJ, speK, speL, speM, smeZ and ssa were tested by real-time PCR while M protein genes (emm genes) were amplified and sequenced by PCR. Results: A total of 377 GAS were isolated from 6 801 throat swab specimens, with the positive rate as 5.5%. There were obvious changes noticed among speC, speG, speH and speK in three years. A total of 45 SAg genes profiles were observed, according to the SAgs inclusion. There were significant differences appeared in the frequencies among two of the highest SAg genes profiles between emm1 and emm12 strains (χ(2)=38.196, P<0.001; χ(2)=72.310, P<0.001). There also appeared significant differences in the frequencies of speA, speH, speI and speJ between emm1 and emm12 strains (χ(2)=146.154, P<0.001; χ(2)=52.31, P<0.001; χ(2)=58.43, P<0.001; χ(2)=144.70, P<0.001). Conclusions: Obvious changes were noticed among SAg genes including speC, speG, speH and speK from patients with scarlet fever or pharyngeal infections in Beijing between 2015-2017. SAg genes including speA, speH, speI and speJ appeared to be associated with the emm 1 and emm 12 strains. More kinds of SAg genes profiles were isolated form GAS but with no significant differences seen in the main SAg genes profiles, during the epidemic period.
Antigens, Bacterial/genetics* ; Bacterial Outer Membrane Proteins ; Bacterial Proteins ; Beijing/epidemiology* ; China/epidemiology* ; Exotoxins ; Female ; Humans ; Membrane Proteins ; Pharyngitis/microbiology* ; Pharynx/microbiology* ; Pregnancy ; Pregnancy Complications, Infectious/microbiology* ; Real-Time Polymerase Chain Reaction ; Scarlet Fever/microbiology* ; Streptococcal Infections ; Streptococcus pyogenes/isolation & purification* ; Superantigens/genetics*

OBJECTIVEClostridium difficile is an obligate anaerobic Gram-positive bacillus, it can cause Clostridium difficile-associated diarrhea (CDAD). This study aimed to investigate the virulence genes and clinical features of CDAD in children by gene detection.

METHODFrom May 2012 to January 2013, the 121 inpatients in Beijing Children's Hospital who suffered from diarrhea after antibiotics treatment were detected for Clostridium difficile virulence genes including the five genes for pathogenic loci (tcdA, tcdB, tcdC, tcdD, tcdE) and the genes for binary toxin CDT (cdtA and cdtB) using polymerase chain reaction (PCR) in order to research the clinical features of CDAD, and analyze target products by sequencing.

RESULTSIn the 121 children with diarrhea, 60 (49.6%) were toxin B-positive,including 12 toxin A-positive and toxin B-positive (A+B+), 48 toxin A-negative but toxin B-positive (A-B+). The toxin A-positive but toxin B-negative (A+B-) specimens or binary toxin (cdtA and cdtB)-positive specimens were not detected. Of 60 tcdB-positive specimens, tcdC, tcdD and tcdE positive specimens were 24 (40%), 25 (42%), 24 (40%), respectively. The sequencing results of tcdA, tcdB, tcdC, tcdD, and tcdE gene were consistent with the reference sequence. In the 60 children with CDAD, infants (≤3 years) accounted for 62% (37/60). The duration of diarrhea was 3-77 days, and 42 (70%) cases had acute diarrhea; 39 (65%) patients had fever, 40 (67%) had anemia, 36 (60%) had abnormal white blood cell count, 30 (50%) had hypoalbuminemia, 25 (42%) had elevated C-reactive protein (CRP). The level of CRP in positive group was significantly higher compared to the negative group (45.0(16.0,89.0) mg/L vs. 19.0(14.5,41.5) mg/L, Z=-2.008, P=0.045). The level of plasma albumin in positive group was significantly lower compared to the negative group (35.3(29.7,39.8) g/L vs. 38.5(33.9,41.5) g/L, Z=-2.610, P=0.009). There were no significant differences in gender, age, duration of diarrhea, hospital staytime, time of using antibiotics and laboratory test between A+B+ group and A-B+ group (all P>0.05).

CONCLUSIONThe main virulence genotype of Clostridium difficile was toxin A-negative but toxin B-positive in this research. The clinical features of CDAD in children were acute diarrhea with fever. Laboratory examination showed that white blood cell count was abnormal, CRP was increased, hemoglobin and plasma albumin were reduced.

Anti-Bacterial Agents ; Bacterial Toxins ; genetics ; Beijing ; C-Reactive Protein ; Child ; Clostridium Infections ; microbiology ; Clostridium difficile ; genetics ; pathogenicity ; Diarrhea ; microbiology ; Fever ; Genes, Bacterial ; Genotype ; Humans ; Infant ; Leukocyte Count ; Polymerase Chain Reaction ; Virulence ; genetics