Hypermucoviscous Multidrug-Resistant Klebsiella variicola Strain LL2208 Isolated from Chinese Longsnout Catfish (Leiocassis longirostris): Highly Similar to Human K. variicola Strains

Outbreaks of bacterial diseases occur in farmed Chinese longsnout catfish (Leiocassis longirostris). Due to limited information on aquatic Klebsiella variicola-infected animals, this study aimed to identify strain LL2208 isolated from diseased L. longirostris, determine its biological features, and evaluate its risk to public health. Strain LL2208 was tested for molecular identification, challenge, string, biofilm formation, and antimicrobial susceptibility. Furthermore, the whole genome of the strain was sequenced and analyzed. Based on molecular identification, strain LL2208 was identified as K. variicola. Artificial infection showed that this strain was moderately virulent to L. longirostris with an LD50 = 7.92 × 107 CFU/mL. Antibiotic sensitivity tests showed that this strain was resistant to penicillins, macrolides, aminoglycosides, amphenicols, glycopeptides, and lincosamide, indicating multidrug resistance. Strain LL2208 has a genome size of 5,557,050 bp, with a GC content of 57.38%, harboring 30 antimicrobial resistance genes and numerous virulence-related genes. Its molecular type was ST595-KL16-O5. Collinearity analysis showed that strain LL2208 was highly similar to the human-derived K. variicola strain. In conclusion, the multidrug-resistant and virulent K. variicola strain LL2208 was isolated from fish and may have originated from humans. These results provide a foundation for further studies on the transmission of K. variicola between humans and aquatic animals.

K. variicola is an opportunistic pathogen that can cause severe infections in humans and animals [12].It is an emerging human pathogen that causes hospital-and communityacquired infections, including respiratory tract, bloodstream, urinary tract, and endodontic Naturally diseased Chinese longsnout catfish samples (N = 7) were collected from a farm (three ponds) in Foshan City, Guangdong Province, China.The water temperature was 29 to 32 • C, and the cumulative mortality rate was 15-40% within 20 d.The liver, spleen, and kidney tissues were collected and streaked on a Columbia blood agar plate (Guangzhou Detgerm Microbiogical Science Ltd., Guangzhou, China) and then incubated at 29 • C for 48 h.The dominant colonies were purified by streaking and re-streaking on brain heart infusion (BHI; Becton, Dickinson and Company, Sparks, MD, USA) agar plates.One of the representative strains (LL2208) was selected and inoculated on a Columbia blood agar plate at 28 • C for 24 h to observe the colony morphology.An electron microscopy negativestaining sample of strain LL2208 was prepared to observe the bacterial characteristics.
Strain LL2208 was inoculated into a BHI liquid medium for expansion.The bacterial cells were collected, and the genomic DNA was extracted using a bacterial genomic DNA extraction kit (Guangzhou Magen Biotechnology, Co., Ltd., Guangzhou, China).The 16S rRNA gene of strain LL2208 was PCR amplified using the universal primers 27f (5 ′ -AGAGTTTGATCMTGGCTCAG-3 ′ ) and 1492r (5 ′ -TACGGYTACCTTGTTACGACT-3 ′ ), and the positive PCR product was sequenced.The 16S rRNA gene was analyzed using Blastn.Further, a phylogenetic tree was constructed using MEGA v7.0.20 with Neighbor Joining (Bootstrap 1000 replicates), and species with distant genetic relationships, such as Citrobacter freundii and Plesiomonas shigelloides, were selected as outgroups.The one-step multiplex PCR was performed to determine the taxonomic status [29].The primers LEN-F and DeoR-R were used, and PCR was performed using the Ex Taq™ Version 2.0 plus dye (Takara Bio, Shiga, Japan) according to the manufacturer's instructions.The PCR amplification conditions were as follows: pre-denaturation at 95 • C for 4 min, followed by 35 cycles (denaturation at 94 • C for 30 s, annealing at 56 • C for 30 s, and extension at 72 • C for 1 min), and final extension at 72 • C for 10 min.Amplified products were collected and sequenced by Sangon Biotech (Shanghai) Co., Ltd., Shanghai, China.

String Test
Strain LL2208 was streaked onto a MacConkey agar (Guangdong HuanKai Microbial Sci.& Tech.Co., Ltd., Guangzhou, China) plate and incubated at 30 • C for 18 h.The length of the viscous filament was observed by making contact with the colony surface using the inoculum ring, with a positive strain being ≥10 mm and a negative strain being <10 mm [12].Strain LL2208 was passed twice, and the string test was repeated.The strain that tested positive on the string test could therefore be classified as hmvKv.

Biofilm Formation Assay
The biofilm formation ability of strain LL2208 was evaluated as previously described, with slight modifications [30].The strain was inoculated briefly into Luria-Bertani (LB) medium (Becton, Dickinson and Company, Sparks, MD, USA), cultured until it reached the logarithmic growth phase (OD 600 = 0.8), and then the bacterial culture was diluted 1:100 in 5 mL of fresh LB broth.Subsequently, 200 µL of the diluted bacterial cultures and 200 µL of LB broth were added, respectively, to each well of 96-well polystyrene microtiter plates and each well in the control group.The 96-well plates were incubated at 35 • C for 24 h.The supernatant was discarded, the wells were washed thrice with sterile water, and methanol solution (200 µL/well) was added to fix the biofilm for 15 min.The methanol solution was discarded, and the 96-well plates were dried for 15 min.The crystal violet solution was added to each well (200 µL/well) to stain for 10 min at room temperature (25 • C), and the excess stain was removed three times with sterile water.Acetic acid (33%, v/v) was added to each well to re-solubilize the attached stain after drying in a 96-well plate.The OD 595 was measured using a microplate reader.The biofilm assay was performed in triplicate.

Challenge Test
Strain LL2208 was inoculated into BHI medium and cultured at 28 • C until the logarithmic growth phase (OD 600 = 0.8-1.0).The bacterial cells were collected by centrifugation at 5000 rpm, and the bacterial concentration was adjusted to 5.0 × 10 8 , 5.0 × 10 7 , 5.0 × 10 6 , 5.0 × 10 5 , and 5.0 × 10 4 CFU/mL using sterile phosphate buffer saline (PBS).Six groups of 20 healthy Chinese longsnout catfish (8.2~13.5 g) each were randomly assigned at a water temperature of 29 ± 1 • C. The challenge test was conducted using a 0.1 mL intraperitoneal injection for each fish.The control group was injected with an equal volume of sterile PBS.After artificial infection, clinical signs and mortality were monitored daily for 14 days, and dead fish were subjected to bacterial isolation and identification.The median lethal dose was calculated using the modified Karber's method [31,32] as follows: "Xk" is the logarithmic value of the maximum dose; "i" is the logarithmic dose difference between adjacent dose groups; "∑p" is the sum of mortality rates for each dose group.

ANI and dDDH Analysis
The average nucleotide identity (ANI) is widely used to classify and identify bacteria by calculating the ANI values of prokaryotic genome sequences [34].ANIu values were calculated between strain LL2208 and related species using the online tool OrthoANIu (https://www.ezbiocloud.net/tools/ani(accessed on 23 April 2024)).Digital DNA-DNA hybridization (dDDH) values between the LL2208 genome and the genomes of related species were analyzed using the Genome-to-Genome Distance Calculator 3.0 (https://ggdc.dsmz.de/ggdc.php(accessed on 24 April 2024)) [35].

Virulence-Related Genes
The virulence-related genes in the genome of strain LL2208 were analyzed using VFanalyzer (http://www.mgc.ac.cn/cgi-bin/VFs/v5/main.cgi (accessed on 8 May 2024)).The virulence genes such as impA, impA2, magA, peg-344, iroB, and iucB were detected using PCR amplification and sequencing.For the PCR amplification, the Ex Taq™ Version 2.0 plus dye was used and the primers were listed in Table 1.The PCR conditions were as follows: pre-denaturation at 95 • C for 4 min, followed by 35 cycles (denaturation at 94 • C for 30 s, annealing at 56-59 • C for 30 s, and extension at 72 • C for 1 min), and final extension at 72 • C for 10 min.Amplified products were collected and sequenced by Sangon Biotech (Shanghai) Co., Ltd., Shanghai, China.
Table 1.Primer sequences of virulence-associated genes.

. Antimicrobial Resistance Genes
Antimicrobial resistance genes were predicted using the RGI 6.0.3 software (https:// card.mcmaster.ca/analyze/rgi(accessed on 22 May 2024)) in the Comprehensive Antibiotic Resistance Database (CARD) with strict hit criteria.

Bacterial Isolation and Identification
Clinical signs of the naturally diseased Chinese longsnout catfish (100-600 g) included a swollen abdomen, hemorrhage in the base of the fin, anal dilatation with hyperemia, fluid accumulation in the abdominal cavity, and liver and kidney enlargement (Figure 1).Many bacteria with similar colony morphologies were isolated from the liver, spleen, and kidney tissues of diseased fish (N = 7).The colonies appeared moist and bumped, with regular edges, smooth surfaces, and a grey-white color (Figure 2A).The bacterial morphology of strain LL2208 was observed by transmission electron microscopy, indicating that the strain was thick, short, and rod-shaped, with a large number of extracellular products, filamentous pili, and outer membrane vesicles (Figure 2B).
Pathogens 2024, 13, 647 6 of 16 copy, indicating that the strain was thick, short, and rod-shaped, with a large number of extracellular products, filamentous pili, and outer membrane vesicles (Figure 2B).The 16S rRNA sequence of strain LL2208 was analyzed through Blastn online alignment, and the results showed that the sequence similarities between strain LL2208 and K. pneumoniae or K. variicola strains were ≥99.94%.A phylogenetic tree of the 16S rRNA sequences was constructed, suggesting that strain LL2208 and K. variicola strains were clustered into the same branch (Figure 3).Specific PCR detection showed that strain LL2208 belonged to K. variicola, with the PCR product sequence being 100% similar to that of the K. variicola strain 15WZ-82 (GenBank accession no.CP032354.1,located in 3,232,504 bp~3,232,992 bp), indicating that strain LL2208 could be classified as K. variicola.The 16S rRNA sequence of strain LL2208 was analyzed through Blastn online alignment, and the results showed that the sequence similarities between strain LL2208 and K. pneumoniae or K. variicola strains were ≥99.94%.A phylogenetic tree of the 16S rRNA sequences was constructed, suggesting that strain LL2208 and K. variicola strains were clustered into the same branch (Figure 3).Specific PCR detection showed that strain LL2208 belonged to K. variicola, with the PCR product sequence being 100% similar to that of the K. variicola strain 15WZ-82 (GenBank accession no.CP032354.1,located in 3,232,504 bp~3,232,992 bp), indicating that strain LL2208 could be classified as K. variicola.

String Test
String tests of strain LL2208 showed that it produced a 2-4 cm viscous string after 18 h of cultivation on MacConkey agar plates (Figure 4).Moreover, strain LL2208 produced a >10 mm viscous string after two passages of cultivation, indicating that it was phenotypically hmvKv.

String Test
String tests of strain LL2208 showed that it produced a 2-4 cm viscous string after 18 h of cultivation on MacConkey agar plates (Figure 4).Moreover, strain LL2208 produced a >10 mm viscous string after two passages of cultivation, indicating that it was phenotypically hmvKv.

String Test
String tests of strain LL2208 showed that it produced a 2-4 cm viscous string after 18 h of cultivation on MacConkey agar plates (Figure 4).Moreover, strain LL2208 produced a >10 mm viscous string after two passages of cultivation, indicating that it was phenotypically hmvKv.

Biofilm Formation Ability
The biofilm assay showed that the OD 595 of strain LL2208 was 1.41 ± 0.10, while the OD 595 of the control group was 0.17 ± 0.01, indicating that strain LL2208 has strong biofilm formation ability (>4 OD 595c ), and it was an hmvKv strain.

Pathogenicity
The major clinical signs of fish infected with strain LL2208 were slow swimming, fluid accumulation in the abdominal cavity, and liver and kidney enlargement.A large number of colonies with similar morphologies were isolated from the liver and kidney tissues of the infected fish, and the similarities of the 16S rRNA sequences between the isolated strains and strain LL2208 were 100%, indicating that the death of L. longirostris was caused by artificial infection.The fish in the control group showed no clinical signs or mortality during the observation period.The LD 50 of strain LL2208 to L. longirostris was 7.92 × 10 7 CFU/mL.

Genomic Annotation and Features
The genome of strain LL2208 contained a circularized chromosome (5,557,050 bp) with no identifiable plasmids and predicted 5158 CDSs (with protein), 88 tRNAs, and 25 rRNAs (5S, 16S, 23S).The whole-genome sequence was deposited in GenBank under the accession no.CP154255.Six gene islands were identified using IslandViewer 4 (Table S1).However, no prophages were found in the LL2208 genome.According to Pathogenwatch analysis, the MLST, capsule type, and O antigen type were ST595, KL16, and O5, respectively.

ANI and dDDH Analysis
The OrthoANIu values of strain LL2208 against K. variicola strains were 99.10% to 99.98%, with the highest OrthoANIu value (99.98%) compared with the WCHKV030666 strain (Table 3).Generally, an ANI value > 95% indicates the presence of the same species; thus, strain LL2208 belongs to K. variicola.The dDDH values of strain LL2208 compared to K. variicola strains were 92.80% to 100% (Table 3), and the DDH values were >70%, confirming the presence of the same species.Therefore, the LL2208 strain was identified as K. variicola and is highly similar to strain WCHKV030666.

Virulence-Associated Genes
A large number of virulence-related genes were predicted in the LL2208 genome, such as adhesion-related genes mrkABCDFHI and fimABCDEFGHIK, iron absorption-related genes iutA, entABCDEFS, fepABCDG, and iroE/iroN, as well as the T6SS secretion system (Table 4).However, genes rmpA and magA were not predicted in the genome.The rmpA, iroB, and peg-344 were detected using PCR amplification and sequencing, whereas impA2, magA, and iucB genes were not (Figure S1).

Antimicrobial Resistance Genes
A total of 30 antimicrobial resistance genes (including repeat genes) were predicted in the LL2208 genome based on CARD, including β-lactamase resistance genes, e.g., bla LEN-16 , pbp3, ompK37, and mdtQ; glycopeptide resistance gene vanG; and fosfomycin resistance genes fosA6 and uhpT.The LL2208 genome contained four categories of antimicrobial resistance genes according to the mechanism of antibiotic resistance: antibiotic efflux, antibiotic inactivation, changes in antibiotic target sites, and reduced antibiotic permeability (Table 5).

Collinearity Relationship
The results of collinearity analysis showed that strain LL2208 had a highly collinear relationship with strain WCHKV030666, and there was no gene rearrangement or inversion in the genome (Figure 5), indicating a high degree of similarity between these two strains.There was good collinearity between strain LL2208 and strain 15WZ-82; however, there were some gene deletions in the genome of strain 15WZ-82.

Discussion
K. variicola is a prevalent opportunistic pathogen that causes infections in humans and animals, including bloodstream infections, and urinary and respiratory-related diseases in humans [23].It is divided into classical K. variicola, hmvKv, and hypervirulent K. variicola (hvKv).Some of these strains exhibit high infectivity and mortality rates [12].Unlike K. pneumoniae, K. variicola strains have not been reported as a pathogen in aquatic animals.Moreover, limited information is available regarding the genetic background of K. variicola isolated from humans and fish.
In this study, strain LL2208 was isolated from the kidney of diseased Chinese longsnout catfish and was identified as K. variicola based on 16S rRNA, ANI, and DDH analysis, as well as specific PCR detection.Generally, the common methods for determining hypervirulent K. pneumoniae include the string test, capsular typing, iron uptake detection, and virulence phenotype detection.In this study, the string test showed that strain LL2208 was characterized as an hmvKv strain.The challenge test showed that strain LL2208 has moderate pathogenicity to the Chinese longsnout catfish, similar to that of K. pneumoniae KP0123 from M. salmoides with LD50 = 3.4 × 10 7 CFU/mL [6].Additionally, antimicrobial sensitivity tests showed that strain LL2208 is a multidrug-resistant strain resistant to antimicrobial agents, such as penicillins, macrolides, amphenicols, lincomycin, and glycopeptides.The results suggest that antimicrobial sensitivity tests should be performed before using antimicrobial agents to prevent and treat infection with K. variicola in fish to avoid the unreasonable use of antibiotics, leading to increases in drug-resistant strains.
The genome of strain LL2208 contains 30 resistance-related genes, such as the β-lactamase resistance genes, including blaLEN-16, pbp3, ompK37, and mdtQ, and the strain was resistant to penicillin but was sensitive to cephalosporins.It harbored CRP, kpnE, kpnF, kpnG, kpnH, and H-NS, contributing to macrolide resistance.Strain LL2208 harbored resistance gene vanG, which is responsible for vancomycin resistance, and it was

Discussion
K. variicola is a prevalent opportunistic pathogen that causes infections in humans and animals, including bloodstream infections, and urinary and respiratory-related diseases in humans [23].It is divided into classical K. variicola, hmvKv, and hypervirulent K. variicola (hvKv).Some of these strains exhibit high infectivity and mortality rates [12].Unlike K. pneumoniae, K. variicola strains have not been reported as a pathogen in aquatic animals.Moreover, limited information is available regarding the genetic background of K. variicola isolated from humans and fish.
In this study, strain LL2208 was isolated from the kidney of diseased Chinese longsnout catfish and was identified as K. variicola based on 16S rRNA, ANI, and DDH analysis, as well as specific PCR detection.Generally, the common methods for determining hypervirulent K. pneumoniae include the string test, capsular typing, iron uptake detection, and virulence phenotype detection.In this study, the string test showed that strain LL2208 was characterized as an hmvKv strain.The challenge test showed that strain LL2208 has moderate pathogenicity to the Chinese longsnout catfish, similar to that of K. pneumoniae KP0123 from M. salmoides with LD 50 = 3.4 × 10 7 CFU/mL [6].Additionally, antimicrobial sensitivity tests showed that strain LL2208 is a multidrug-resistant strain resistant to antimicrobial agents, such as penicillins, macrolides, amphenicols, lincomycin, and glycopeptides.The results suggest that antimicrobial sensitivity tests should be performed before using antimicrobial agents to prevent and treat infection with K. variicola in fish to avoid the unreasonable use of antibiotics, leading to increases in drug-resistant strains.
The typical virulence factors of the Klebsiella genus include capsular polysaccharides, pili/fimbriae, iron-binding siderophores, lipopolysaccharides, outer membrane proteins, and T6SS [39].Type I fimbriae are encoded by fim gene clusters and can bind to glycoproteins in epithelial cells, contributing to bacterial colonization; type III fimbriae are encoded by mrkABCDF, which is related to biofilm formation and invasion.Strain LL2208 contained type I and III fimbrial gene clusters, including fimABCDEFGHIK and mrkABCDFHI, implying that this strain has strong adhesion ability and biofilm formation ability [40].Siderophores are closely related to hypervirulent K. pneumoniae, including aerobactin, enterobactin, yersiniabactin, and salmochelin [39].In K. pneumoniae, enterobactin is the main siderophore for iron uptake, and salmochelin is common in hypervirulent K. pneumoniae (hvKp) strains; more than 90% of these are associated with pyogenic liver abscesses and effective infection in hvKp requires aerobactin [39].Generally, siderophores are essential for the proliferation and pathogenicity of bacteria and can affect tissue localization and systemic dispersion.Strain LL2208 contained genes associated with the synthesis of salmochelin (iroE and iroN), enterobactin (entABCDEFS and fepABCDG), and aerobactin (iutA), indicating that it could synthesize salmochelin, enterobactin, and aerobactin, which may enhance its pathogenicity.
The virulence genes rmpA, rmpA2, peg344, iroB, and iucA can distinguish between hvKP and classical K. pneumoniae (cKP).Gene rmpA was not identified in the genome of strain LL2208.However, rmpA, peg344, and iroB were detected using PCR amplification and sequencing, suggesting that the hypermucoviscous phenotype of strain LL2208 was related to rmpA.Moreover, strain LL2208 may have low-copy plasmids, and the plasmid sequences were not assembled because the sequencing depth was insufficient.Strain LL2208 contained rmpA, peg344, iroB, and iucA genes (Table 4), suggesting that this strain was an hvKv strain based on the presence of virulence-associated genes.
K. variicoa strains are becoming a threat to public health worldwide.Recently, the number of reports on human hvKv strains has increased.A multidrug-resistant K. variicoa strain (ST17) resulted in a higher mortality rate (54.5%) in newborns [41].The hvKv strain 21072329 isolated from an elderly patient belonged to the ST11-KL47 type and is resistant to carbapenems and third-and fourth-generation cephalosporins [42].K. variicola strain wxkv2055, with ST595-KL16-O5 genotype, was isolated from human blood [43], consistent with the report that strain LL2208 also belongs to the same genotype.Furthermore, the genotype of K. variicola strain WCHKV030666 isolated from humans was ST595-O5, and the capsule type was similar to KL16 (wzi251) [37].Moreover, the strains LL2208 and WCHKV030666 showed a highly collinear relationship, indicating they have a common ancestral lineage.A carbapenem-resistant K. variicola strain 15WZ-82 isolated from human sputum exhibited high-level virulence in mice and showed good collinearity with strain LL2208 [38].These results indicate that strain LL2208 can potentially become an hvKv.K. variicola, a co-pathogenic bacterium found between humans and aquatic animals, can cause infection in farmed fish if the aquaculture water is contaminated with this strain.Moreover, K. variicola, as a potential foodborne pathogen, poses a risk to human health [44].
In this study, enrofloxacin and sulfonamides are recommended to prevent and control the infection of K. variicola in Chinese longsnout catfish according to the results of the antimicrobial sensitivity test.However, it is necessary to accelerate the research and development of prevention and control products for K. variicola, which belongs to the K. pneumoniae complex, to curb the spread of multidrug-resistant strains.For example, lytic phage was isolated from water as a biocontrol agent against multidrug-resistant K. variicola, inhibiting its growth in vitro and in vivo [45].Oral treatment with live commensal Bifidobacterium longum 5 1A prevents detrimental lung inflammation caused by K. pneumoniae strains [46].A previous report also showed that plant extracts could effectively inhibit the growth of K. pneumoniae, and peppercorn extracts were the most potent growth inhibitors [47].Vaccines are a promising strategy for preventing infections caused by K. pneumoniae strains and reducing the spread of multidrug-resistant strains [48].

Conclusions
A multidrug-resistant hmvKv strain LL2208 with strong biofilm formation ability was isolated from diseased fish.Genome analysis revealed that the strain harbored antimicrobial resistance genes, including bla LEN-16 , ompK37, pbp3, and vanG, and it contained numerous virulence-associated genes, including type I and III fimbrial gene clusters, siderophores, and T6SS.The genotype was ST595-KL16-O5.Comparative genomics analysis revealed strain LL2208 is highly similar to human-derived K. variicola strains, suggesting that the spread of K. variicola strains in diseased fish poses a potential risk to public health.Monitoring the epidemiology, pathogenicity, and antimicrobial resistance of K. variicola as an emerging pathogen in fish is crucial for disease prevention and safeguarding public health.

Figure 1 .
Figure 1.Clinical signs of naturally occurring disease in Chinese longsnout catfish.(A) Swollen abdomen, hemorrhage in the base of the fin, anal dilatation with hyperemia; (B) fluid accumulation in the abdominal cavity, and liver and kidney enlargement.

Figure 1 .
Figure 1.Clinical signs of naturally occurring disease in Chinese longsnout catfish.(A) Swollen abdomen, hemorrhage in the base of the fin, anal dilatation with hyperemia; (B) fluid accumulation in the abdominal cavity, and liver and kidney enlargement.

Figure 2 .
Figure 2. Morphological characteristics of the colony (A) and bacterium (B) of strain LL2208.Strain LL2208 was streaked on Columbia blood agar plate and incubated at 29 • C for 48 h.The bacterial morphology of strain LL2208 was observed using transmission electron microscopy (HT7800; Hitachi, Tokyo, Japan) with 6000× magnification.

Figure 3 .
Figure 3.The phylogenetic tree constructed based on 16S rRNA gene sequences.

Figure 3 .
Figure 3.The phylogenetic tree constructed based on 16S rRNA gene sequences.

Figure 3 .
Figure 3.The phylogenetic tree constructed based on 16S rRNA gene sequences.

Figure 4 .
Figure 4. String test of strain LL2208 with initial strain (A) and two passages (B).Figure 4. String test of strain LL2208 with initial strain (A) and two passages (B).

Figure 4 .
Figure 4. String test of strain LL2208 with initial strain (A) and two passages (B).Figure 4. String test of strain LL2208 with initial strain (A) and two passages (B).

Table 2 .
Results of drug sensitivity tests of strain LL2208.

Table 3 .
OrthoANIu and dDDH analysis between LL2208 and reference Klebsiella strains.

Table 4 .
Virulence-associated genes in the genome of strain LL2208 were predicted by VFanalyzer.

Table 5 .
Genes associated with the antibiotic resistance of strain LL2208.