Spatial distribution features of sequence types of moderate and strong earthquake in Chinese mainland

Based on 294 earthquake sequences with magnitude greater than or equal to 5.0 occurred in Chinese mainland since 1970, the spatial distribution features of sequence types have been studied. In southwestern China, it takes mainshock-aftershock sequence type （MAT） as the major in Chuan-Dian rhombic block and concerned Xianshuihe-Anninghe-Xiaojiang seismic belt, as well as in Jinshajiang-Honghe seismic belt. Multiple mainshock type （MMT） mainly distributes in western Yunnan, and Longlin and Lancang areas in Tengchong-Baoshan block in west of Nujiang-Lancangjiang fault zone. A few isolated earthquake type （IET） mainly occurred in northwestern Sichuan and there is no IET occurred in Yunnan region. In northwestern China, it takes mainshock-aftershock sequence type （MAT） as the major in west segment of South Tianshan in Xinjiang region. Some MMT also occurred in this area in the intersection of Kalpin block and the Puchang fault zone. It takes IET as the major in middle Tianshan in Xinjiang. Along the Qilianshan seismic belt, most of sequences are MAT. In Qinghai region, it takes MAT as the major, but the regional feature of the spatial distribution of sequence types is not very clear. In North China, it takes MAT as the major in Yinshan-Yanshan-Bohai seismic belt, north edge of North China, and in Hebei plain seismic belt, as well as in sub-plate of lower river area of Yangtze River. In intersection of north segment of Shanxi seismic belt and the NW-trending Yinshan-Yanshan-Bohai seismic belt, there are several moderate or strong MMT with magnitude from 5.0 to 6.0 occurred. In south of North China around the latitude line of 35°N, it takes IET as the major. The spatial distribution of sequence types is relevant to the patterns of tectonic movements. MAT is mostly produced by the ruptures of locked units or asperities or the neonatal separating segments inside the fault zones. MMT is generally relevant to the conjugate structures or intersection of many tectonic settings. Further extension of simple fault often produces IET. Spatial distribution of sequence types is also correlative to the regional and deep environment of crustal medium to some extent. MAT mainly distributes in high velocity area in upper crust or in the transition zone between high velocity area and low velocity area, MMT mostly occurred in the low velocity area in upper crust.

Emergence of Klebsiella pneumoniae carbapenemase-producing Escherichia coli sequence type 131 in Hangzhou, China

Background Klebsiella pneumoniae carbapenemase （KPC）-producing Escherichia （E.） coil has been reported in China since 2008.However,there is no information about the molecular epidemiology of KPC-producing E.coil in China.In this study,we aimed to investigate the sequence type （ST） and characteristics of KPC-producing E.coil isolates in China.Methods Three carbapenem-resistant isolates of E.coil （E1,E2,and E3） from one teaching hospital in Hangzhou covering a one year period were analyzed.Antibiotic susceptibility was determined by Etest.Pulsed-field gel electrophoresis （PFGE） and multilocus sequence typing （MLST） were used for epidemiological analysis.The genetic structure around blaKPC,the major plasmid incompatibility typing,and the identification of 3-lactamase gene types were performed by PCR and the positive products were subsequently sequenced.Plasmids were analyzed by transformation,restriction,and Southern blotting.Results PFGE demonstrated that patterns of isolates E1 and E2 were clonally-related and designated as patterns A1 and A2; pattern of isolate E3 was different and designated as pattern B.MLST analysis showed that the three isolates displayed one common sequence type ST131.The identification of bla gene types by PCR and sequencing showed that blaKPC-2,blaCTX-M-14,and blaTEM-1 were detected in all three isolates.All three isolates carried a KPC-2-encoding plasmid of the IncN replicon.Plasmid analysis and hybridization experiments showed that the isolates were found simultaneously to carry two or four plasmids.The blaKPc-2 gene in E1 and E2 was located in a plasmid with size of ca.50 kb.However,the blaKPC-2 gene in E3 was located in a plasmid with size of ca.130 kb.Conclusions E.coil ST131 with KPC-2 β-1actamase has emerged in China,which enlarges the geographical area where the ST131 KPC-oroducing E.coil strains have diffused.

ISHIKAWA TYPE ITERATIVE SEQUENCES WITH ERRORS FOR LIPSCHITZIAN φ-STRONGLY ACCRETIVE OPERATOR EQUATIONS IN ARBITRARY BANACH SPACES

In this paper, we investigate the problem of approximating solutions of the equations of Lipschitzian ψ-strongly accretive operators and fixed points of Lipschitzian ψ-hemicontractive operators by lshikawa type iterative sequences with errors. Our results unify, improve and extend the results obtained previously by several authors including Li and Liu (Acta Math. Sinica 41 (4)(1998), 845-850), and Osilike (Nonlinear Anal. TMA, 36(1)(1999), 1-9), and also answer completely the open problems mentioned by Chidume (J. Math. Anal. Appl. 151 (2)(1990), 453-461).

On complete convergence for Stout's type weighted sums of NOD sequence

In this paper, the complete convergence for the weighted sums of independent and identically distributed random variables in Stout [9] is improved and extended under NOD setup.The more optimal moment condition is given. The main results also hold for END sequence.

Method discussion for quick response grey prediction of stronger aftershocks of an earthquake sequence

In this paper, we take occurrence process of early strong aftershocks of a main after shock type′s earthquake sequence as a complex grey system, and introduce predicting method for its stronger aftershocks by grey predicting theory. Through inspection prediction for 1998 Zhangbei M S=6.2 earthquake sequence, it shows that the grey predicting method maybe has active significance for the investigation of quick response prediction problems of stronger aftershocks of an earthquake sequence.

ST of Streptococcus pneumonia Circulating in Burkina Faso before the Introduction of PCV-13, 2013

Introduction: Burkina Faso experiences regular cases of Streptococcus pneumoniae meningitis. As part of the strategy to reduce cases of meningitis, the 13-valent pneumococcal conjugate vaccine (PCV-13) has been introduced in the Expanded Programme on Immunisation (EPI). Despite these efforts, there are some cases of pneumococcal meningitis including both vaccine and non-vaccine serotypes. The objective of this study was to describe the pneumococcal sequence types (ST) circulating in Burkina Faso before the introduction of the 13-valent pneumococcal conjugate vaccine (PCV-13). Methods: It was a descriptive cross-sectional study that took place from 27th October 2013 to 7th January 2014. S. pneumoniae strains were collected in Burkina Faso and Multi Locus Sequence Typing (MLST) was performed at the Pneumococcal Laboratory at the Centers for Disease Control and Prevention (CDC) in the USA (United States of America). MLST consists of 4 steps: amplification, purification, sequencing and interpretative reading of the results. The amplification used 7 primers consisting of sequences of aroe, gdh, gki, recP, spi, xpt, ddl genes. Results: Of 37 strains tested, 10 serotypes were identified. Serotype 1 was prevalent in 48.7% (18/37) followed by serotype 25F in 10.8% (4/37). Serotypes 5 and 12F/12A/12B/44/46 were 8.1% (3/37) each. Serotype 1 contained 5 STs including ST303 24.3% (9/37), ST217 8.1% (3/37) and ST618 8.1% (3/37);followed by serotype 25F with ST105 10.8% (4/37), serotype 5 with ST289 8.1% (3/37) and serogroup 12F/12A/12B/44/46 with ST 989 8.1% (3/37). Conclusion: Pneumococci are characterised by their great variability both in number of serotypes and in ST within the same serotype. Thus, 10 serotypes have been identified. Also, within serotype 1, 5 different STs have been described. These data indicate the complexity of the pneumococcus which is strongly involved in purulent bacterial meningitis at national level. This requires continuous surveillance of pneumococcal meningitis through laboratory capacity building.

Disease burden,antimicrobial resistance and molecular characterization of invasive group B Streptococcus among non-pregnant adults in Malaysia:A protocol study

and pili genes are also investigated.Methods:This multicentre,prospective,observational study is conducted in seven major tertiary hospitals in Malaysia among non-pregnant adults.Simultaneously,a retrospective study is conducted in the selected hospitals with similar approaches.GBS isolates are subjected to phenotyping,serotyping by multiplex PCR,antimicrobial susceptibility testing and PCR-detection of GBS virulence and pilus genes.Seven housekeeping genes are amplified and sequenced for multi-locus sequence typing.Discussion:Findings from the study may contribute to the management of clinical practice to diagnose and prevent GBS related diseases in a timely manner.Prudent use of antibiotics is encouraged by monitoring antimicrobial resistance.

Characteristics of colistin-resistant Escherichia coli from pig farms in Central China

The emergence and dissemination of colistin resistance in Enterobacterioceae mediated by plasmid-borne mcr genes in recent years now pose a threat to public health.In this study,we isolated and characterized colistin-resistant and for mcr-positive£coli from pig farms in Central China.Between 2018 and 2019,594 samples were collected and recovered 445 E.coli isolates.Among them,33 with colistin resistance phenotypes and 37 that were positive for mcr genes were identified,including 34 positive for mcr-1,one positive for mcr-3,and two positive for both mcr-1 and mcr-3.An insertion of nine bases("CTGGATACG")into mcr-7 in four mcr-positive isolates led to gene dysfunction,and therefore did not confer the colistin resistance phenotype.Antimicrobial susceptibility testing revealed that 37 mcr-positive isolates showed severe drug resistance profiles,as 50% of them were resistant to 20 types of antibiotics.Multilocus sequence typing revealed a heterogeneous group of sequence types in mcr-positive isolates,among which ST10(5/37),ST156(5/37),and 5T617(4/37)were the predominant types.Plasmid conjugation assays showed that mcr-carrying plasmids of 25 mcr-positive isolates were conjugated with£coli recipient,with conjugation frequencies ranging from 1.7 × 10^(-6) to 4.1 × 10^(-3) per recipient.Conjugation of these mcr genes conferred a colistin resistance phenotype upon the recipient bacterium.PCR typing of plasmids harbored in the 25 transconjugants determined six types of plasmid replicons,including lncX4(14/25),FrepB(4/25),Incl2(3/25),lncHI2(2/25),FIB(1/25),and Inch(1/25).This study contributes to the current understanding of antibiotic resistance and molecular characteristics of colistin-resistant£coli in pig farms.

Molecular Characteristics of Neisseria meningitidis Isolated during an Outbreak in a Jail: Association with the Spread and Distribution of ST-4821 Complex Serogroup C Clone in China

Objective To characterize the meningococcal strains isolated from cases and close contacts with meningococcal disease associated with an outbreak in a jail in May 2010 by investigating the national distribution of hyperinvasive ST-4821 serogroup C clone associated with this outbreak. Methods The cases were described based on the clinical symptoms and laboratory results. Pharyngeal swabs were cultured for N. meningitidis from men in the jail. Meningococcal isolates were identified by serogrouping, pulsed-field gel electrophoresis （PFGE） and multilocus sequence typing （MLST）, respectively. Four hundred and sixteen serogroup C N. meningitidis strains were collected from 27 provinces between 2003 and 2010 for a nationwide survey and analyzed by PFGE and MLST. Results Three persons in a jail system were infected with invasive N. meningitidis serogroup C. All isolates tested had matching PFGE patterns and belonged to the multilocus sequence type （ST） 4821 clonal complex. All 47 N. meningitidis strains were identified from the pharyngeal swabs of 166 peoples in the jail, and 26 of them belonged to ST-4821 serogroup C clone, and 90.14% （375/416） serogroup C strains identified in the nationwide survey belonged to the ST-4821 complex. The ST-4821 serogroup C clone was spread nationwide, distributed in 24 provinces, especially in eastern provinces between 2003 and 2010. Conclusion Endemic transmission and carriage rate of ST-4821 serogroup C clone are high in this jail system. The ST-4821 serogroup C clone is spreading in China and nationwide distributed despite the existence of some effective vaccines.

Genetic Diversity, Antimicrobial Resistance, and Virulence Genes of Aeromonas Isolates from Clinical Patients, Tap Water Systems, and Food

Objective This study aimed to evaluate the genetic diversity,virulence,and antimicrobial resistance of Aeromonas isolates from clinical patients,tap water systems,and food.Methods Ninety Aeromonas isolates were obtained from Ma’anshan,Anhui province,China,and subjected to multi-locus sequence typing(MLST)with six housekeeping genes.Their taxonomy was investigated using concatenated gyr B-cpn60 sequences,while their resistance to 12 antibiotics was evaluated.Ten putative virulence factors and several resistance genes were identified by PCR and sequencing.Results The 90 Aeromonas isolates were divided into 84 sequence types,80 of which were novel,indicating high genetic diversity.The Aeromonas isolates were classified into eight different species.PCR assays identified virulence genes in the isolates,with the enterotoxin and hemolysin genes act,aer A,alt,and ast found in 47(52.2%),13(14.4%),22(24.4%),and 12(13.3%)of the isolates,respectively.The majority of the isolates(≥90%)were susceptible to aztreonam,imipenem,cefepime,chloramphenicol,gentamicin,tetracycline,and ciprofloxacin.However,several resistance genes were detected in the isolates,as well as a new mcr-3 variant.Conclusions Sequence type,virulence properties,and antibiotic resistance vary in Aeromonas isolates from clinical patients,tap water systems,and food.

Genetic and Antibiotic Resistance Characteristics ofCampylobacterjejuni Isolated from Diarrheal Patients,Poultry and Cattle in Shenzhen

Objective To investigate genetic and antibiotic resistance characteristics of Campylobacter jejuni(C. jejuni) isolated from Shenzhen. Methods Multilocs sequence typing and agar dilution methods were used to define the genotype and antibiotic resistance of C. jejuni, respectively. Results In total, 126 C. jejuni strains were isolated. The prevalence of C. jejuni was 5.3% in diarrheal patients. The prevalence in poultry meat(36.5%) was higher than that in cattle meat(1.1%). However, the prevalence in poultry cloacal swabs(27.0%) was lower than that in cattle stool(57.3%). Sixty-two sequence types were obtained, among which 27 of the STs and 10 alleles were previously unreported. The most frequently observed clonal complexes were ST-21(11.9%), ST-22(10.3%), and ST-403(7.1%). ST-21, ST-45, ST-354, ST-403, and ST-443 complexes overlapped between isolates from patients and cattle, whereas ST-45 and ST-574 complexes overlapped between isolates from patients and poultry. All C. jejuni were resistant to at least one antibiotic. The highest resistance rate was toward ciprofloxacin(89.7%), followed by tetracycline(74.6%), and nalidixic acid(69.0%). Conclusion This is the first report of the genotypes and antibiotic resistance of C. jejuni in Shenzhen. Overlapping clonal complexes were found between isolates from patients and cattle, and between patients and poultry.

Statistical features of aftershock distribution size for moderate and large earthquakes in Chinese mainland

Based on data of earthquake sequences with Ms≥5.0 in Chinese mainland from 1970 to 2004, for different sequence types and different rupture modes of the main shock, the relationship between aftershock distribution size R and the magnitude of the main shock Mo has been studied statistically. Considering the rupture mode of the main shock, we give the quantitative statistical relationships between R and Mo under 95% confidence level for different sequence typos. Qualitatively, lgR, the logarithm of the aftershock distribution size, is positively correlative to the M0, but the data distribution is dispersed. Viewing from different sequence typos, the correlation between R and M0 is very weak for isolated earthquake type （lET） sequence, R distributes in the range from 5 to 60 km; For mainshock-aftershock type （MAT）, lgR is positively correlative to M0; For multiple main shock type （MMT）, the corelation between lgR and M0 is not very obvious when M0≤6.2 and R distributes in the range from 5 to 70 km, while it shows a linear correlation when M0≥6.3. The statistical results also show that the occupational ratios of different sequence types for strike-slip and oblique slip are almost the same. But for dip-slip （mostly are thrust mechanisms）, the ratio of MAT is higher than that of IET and MMT. Comparing with previous results, it indicates that, when M0 is large enough, R is mainly determined by M0 and there is almost no relationship with the rupture mode of the main shock.

MLST analysis of genetic diversity of Bacillus coagulans strains to evaluate effects on constipation model

Bacillus coagulans can help ameliorate or prevent gastrointestinal diseases, but the genetic relationships among B. coagulans isolates are not well studied. Multilocus sequence typing analysis was conducted on 57 isolates of B. coagulans from 22 provinces or autonomous regions in China. B. coagulans isolates were highly diverse and a total of 33(sequence typings) STs were found. These isolates had a weak clonal population structure and strong indications of intraspecies recombination. The evolution direction of B. coagulans was not correlated with geography or isolation source. Fifteen strains were selected for further analysis based on proximity relationships from the phylogenetic tree. Five isolates(B. coagulans-1, B. coagulans-10, B. coagulans-39, B. coagulans-70 and B. coagulans-71) with good spore-forming ability relative to the rest of the isolates were evaluated for constipation relief. B. coagulans-39 significantly relieved constipation symptoms in mice by regulating intestinal flora, increasing the production of short-chain fatty acids and restoring the level of gastrointestinal regulatory peptides. Comparative genomic analysis showed the beneficial effects of B. coagulans-39 might be associated with specific functional genes that are involved in the utilization of various carbohydrates as primary substrates and short-chain fatty acid production.

Prevalence and fuoroquinolone resistance of Campylobacter spp.isolated from beef cattle in Japan

Beef is a source of human Campylobacter infections.Antimicrobial treatment is needed when patients are immuno‑compromised or have other comorbidities.Therefore,we investigated the prevalence and antimicrobial resistance of Campylobacter spp.in beef cattle in Japan.Rectal swab samples were collected from 164 beef cattle at an abattoir between March 2021 and August 2021,and Campylobacter spp.were isolated from 94(57.3%)cattle.C.jejuni and C.coli were isolated from 68 and 26 cattle,respectively.For Campylobacter jejuni,the resistant rates against ampicillin,tetracycline and ciprofoxacin were 20.6,75.0 and 64.7%,respectively.For C.coli,the resistant rates against ampicil‑lin,tetracycline and ciprofoxacin were 53.8,76.9 and 88.5%,respectively.No Campylobacter isolates were resistant to erythromycin.By multilocus sequence typing,C.jejuni and C.coli isolates were classifed into 22 and 2 sequence types(STs).The top three STs of C.jejuni were ST806(12 isolates),ST21(nine isolates),and ST459(eight isolates).The most frequent ST of C.coli was ST1068(23 isolates).The results suggest that Campylobacter spp.are prevalent in the gastrointestinal tract of beef cattle slaughtered at abattoirs.Furthermore,the administration of erythromycin is efec‑tive against human campylobacteriosis caused by beef consumption.Monitoring the prevalence and antimicrobial resistance of Campylobacter spp.in beef cattle could be useful for managing the risk of human campylobacteriosis.

Dismantling Marchandiomphalina into Agonimia(Verrucariaceae)and Lawreymyces gen.nov.(Corticiaceae):setting a precedent to the formal recognition of thousands of voucherless fungi based on type sequences

Based on an unexpected result of obtaining molecular sequence data from tropical representatives of the genus Normandina,we revised the biological concept of the neotropical taxon Marchandiomphalina foliacea.The obtained data let us conclude that M.foliacea is not a basidiomycete,as originally proposed,but belongs in Verrucariaceae,in the genus Agonimia,including its perithecia which had been identified with the lichenicolous Norrlinia peltigericola.The ITS(and nuLSU)sequences previously obtained from M.foliacea,seemingly confirming its status as a basidiomycete,are from an unmanifested lichenicolous fungus,present also in numerous specimens of Normandina.ITS data suggest the presence of seven lineages that can be recognized at the species level,forming two clusters:one cluster of three lineages found in thalli of M.foliacea,and a second cluster of four lineages found in thalli of Normandina.This pattern is similar to what has recently been found in the basidiomycete genus Cyphobasidium occurring predominantly in Parmeliaceae lichens.We propose the combination of Omphalina foliacea into the genus Agonimia,as Agonimia foliacea(P.M.Jørg.)Lucking&Moncada,comb.nov.,and place Marchandiomphalina in synonymy with Agonimia.To formally recognize the unnamed lichenicolous basidiomycete present in Agonimia and Normandina thalli,we take advantage of provision ICN Art.40.5 in the Code and describe the unmanifested fungus as a new genus,with seven new species,even if no physical type specimens can be preserved(except for the corresponding host lichens which,however,do not show the features of the fungus):Lawreymyces Lucking&Moncada,gen.nov.(Type:L.palicei),with L.bogotensis Lucking&Moncada,sp.nov.,L.columbiensis Lucking&Moncada,sp.nov.,L.confusus Lucking&Moncada,sp.nov.,L,foliaceae Lucking&Moncada,sp.nov.,L.palicei Lucking&Moncada,sp.nov.,L.pulchellae Lucking&Moncada,sp.nov.,and L.spribillei Lucking&Moncada,sp.nov.This opens the door to the formal recognition of thousands of species of voucherless fungi detected through environmental sequencing techniques under the current Code.

ITERATIVE PROCESS TO -HEMICONTRACTIVE OPERATOR AND-STRONGLY ACCRETIVE OPERATOR EQUATIONS

Let E be an arbitrary real Banach space and K be a nonempty closed convex subsets of E. Let T:K→K be a uniformly continuous _hemicontractive operator with bounded range and a n,b n,c n,a ′ n,b ′ n,c ′ n be sequences in [0,1] satisfying:ⅰ) a n+b n+c n=a ′ n+b ′ n+c ′ n=1. n≥0; ⅱ) lim b n= lim b ′ n= lim c ′ n= 0; ⅲ)∑∞n=0b n=∞; ⅳ) c n=o(b n). For any given x 0,u 0,v 0∈K, define the Ishikawa type iterative sequence x n as follows: x n+1 =a nx n+b nTy n+c nu n, y n=a ′ nx n+b ′ nTx n+c ′ nv n (n≥0), where u n and v n are bounded sequences in K. Then x n converges strongly to the unique fixed point of T. Related result deals with the convergence of Ishikawa type iterative sequence to the solution of _strongly accretive operator equations.

Avramov–Martsinkovsky Type Exact Sequences with Tor Functors

For two classes of right R-modules W, X such that P W X, where P is the class of projective right R-modules, we show that there is an Avramov-Martsinkovsky type exact sequence with generalized Tate homology functor Tor^X,W, relative homology functors Tor^W and Tor^X. Many results in Iacob [Comm. Algebra, 35, 1589-1606 （2007）] and Liang [Algebr. Represent. Theory, 16, 1541-1560 （2013）] are generalized and improved.

Molecular Diversity of <i>Staphylococcus aureus</i>from the Nares of Hospital Personnel, HIV-Positive and Diabetes Mellitus Patients in Yaounde Cameroon

Nasal carriage of Staphylococcus aureus has been identified as a risk factor for the development of staphylococcal infections caused by endogenous colonizing strains. Information on the genotypic diversity of Staphylococcus aureus is relevant for managing epidemiological and clinical challenges resulting from the evolutionary differences of this bacterium. The objective of this study was to determine and compare the molecular diversity of Staphylococcus aureus isolates from three high-risk populations in Yaounde, Cameroon. Molecular analysis confirmed that 95% of 100 tested isolates were S. aureus. The mecA and Panton Valentine-Leukocidin (PVL) genes (lukS/F-PV) were detected in 37% (35/95) and 43% (41/95) of isolates respectively and 18% (17/95) of the isolates harboured both the mecA and lukS/F-PV genes. A mixed distribution of both methicillin sensitive S. aureus (MSSA)/PVL and methicillin resistant S. aureus (MRSA)/PVL strains were detected within the study population. Community associated MRSA accounted for 94% (33/35) of the isolates, further classified into allotypes SCCmec type IV 54% (19/35) and SCCmec type V 40% (14/35), while two isolates were hospital associated SCCmec type II strains. A majority of the isolates harboured a single aggressive gene regulator allele agr type I. Pulsed Field Gel Electrophoresis (PFGE) generated 18 pulsotypes that grouped isolates irrespective of the study population. Multilocus Sequence Typing (MLST) of 12 selected isolates was assigned to six pandemic clonal complexes (CC): CC5 (ST5), CC8 [ST8, (n = 3)], CC15 (ST 15), CC25 (ST 25), CC72 [ST72 (n = 2)] and CC121 [ST 121 (n = 2)] and three atypical sequence types ST 508, ST 699 (CC45) and ST 1289 (CC 88). The study population represents an important reservoir for MRSA, MRSA-PVL and MSSA-PVL which could serve as focal point for further dissemination bringing about significant clinical and epidemiological implications. The predominance of SCCmec IV and agr types in this setting warrants further investigation. Isolates were genetically diverse with MLST indicating that pandemic ST8 was predominant. Detection of atypical STs has provided an insight into the necessity for constant monitoring.

Family Competition Pheromone Genetic Algorithm for Comparative Genome Assembly

Genome assembly is a prerequisite step for analyzing next generation sequencing data and also far from being solved. Many assembly tools have been proposed and used extensively. Majority of them aim to assemble sequencing reads into contigs; however, we focus on the assembly of contigs into scaffolds in this paper. This is called scaffolding, which estimates the relative order of the contigs as well as the size of the gaps between these contigs. Pheromone trail-based genetic algorithm （PGA） was previously proposed and had decent performance according to their paper. From our previous study, we found that family competition mechanism in genetic algorithm is able to further improve the results. Therefore, we propose family competition pheromone genetic algorithm （FCPGA） and demonstrate the improvement over PGA.