ObjectiveTo investigate the whole genomic characteristics and phylogenetic relationships of clinical isolates of enteroaggregative Escherichia coli (EAEC) in diarrhea outpatients in Pudong New Area, Shanghai. MethodsBased on the diarrheal disease surveillance network in Pudong New Area, Shanghai, whole-genome sequencing was performed on a total of 55 EAEC strains isolated from fecal samples of the diarrhea outpatients from January 2015 to December 2019. The genome analyses based on raw sequencing data encompassed genome size, coding genes, dispersed repeat sequences, genomic islands, and protein coding regions, and pan-genome analyses were conducted simultaneously. Contigs sequences assays were performed to analyze molecular characteristics including serotypes, antibiotic resistance genes, and virulence factors. The phylogenetic clusters and multilocus sequence typing (MLST) were identified, and a phylogenetic tree was constructed. ResultsEAEC exhibited an open pan-genome. The predominant serotype of EAEC in diarrhea outpatients in Pudong New Area was O130:H27, and the carriage rate of β-lactam resistance genes was the highest (67.27%, 37/55). A total of 29 virulence factors and 106 virulence genes were identified, phylogenic group B1 was the predominant group, and clonal group CC31 was the dominant clonal group. The strain distribution was highly heterogeneous. ConclusionThe genomic characteristics of EAEC displayed significant strain polymorphism. It is necessary to develop effective strategies for differential diagnosis and improve detection capabilities for infection with EAEC of different serotypes and genotypes.

Objectives:To investigate the relationship between pelvic landmarks on body surface and the trajectory of S2 alar-iliac(S2AI)screws in populations of different genders and body mass indexes.Methods:A retrospective analysis was conducted on 150 patients who underwent pelvic CT scans in the Affiliated Hospital of Southwest Medical University between February 2022 and February 2024.Basic demographic data including age,gender,weight,and height were collected.Pelvic models were reconstructed by CT,and screw trajectories were simulated on the models.The screw trajectories were extended to intersect with the skin sur-face,and the intersection points of the safe trajectories with skin formed a safety zone on the body surface.The shortest distances from the anterior superior iliac spine(ASIS),anterior inferior iliac spine(AIIS),and greater trochanter(GT)to the safe zone were measured.The length of the line connecting ASIS and GT on the surface,length of such line intersecting with the safety zone,length from ASIS to the safety zone along such line,length from GT to the safety zone along such line were measured.Group comparisons were performed based on gender and BMI[underweight group(BMI＜18.50kg/m2),normal group(18.50kg/m2≤BMI＜24.00kg/m2),overweight group(24.00kg/m2≤BMI＜28.00kg/m2),obese group(BMI≥28.00kg/m2)].Results:In males,the shortest distances from ASIS,AIIS,and GT to the safe zone were 19.87±3.66mm,33.66±3.33mm,and 39.53±3.56mm,respectively;In females,they were 19.31±3.41mm,33.23±3.45mm,and 38.74±3.23mm,respectively.No statis-tically significant differences were observed between gender groups(P＞0.05).The shortest distance from ASIS,AIIS,GT to safety zone was 14.03±1.64mm,26.79±1.15mm,43.68±1.32mm in the underweight group,17.67±2.36mm,31.73±1.77mm,41.18±2.43mm in the normal group,21.85±1.37mm,35.78±1.76mm,36.80±1.68mm in the overweight group,and 25.66±0.84mm,38.75±0.88mm,and 36.80±1.68mm in the obese group,respec-tively.Intergroup comparisons between the four groups were statistically significant(P＜0.05),and pairwise com-parisons within groups were statistically significant(P＜0.05).In males,the length of the line connecting ASIS and GT was 129.43±6.42mm,the length of the line intersecting with safety zone was 30.72±5.27mm,the length from ASIS to safety zone along the line was 33.61±8.82mm,and the length from GT to safety zone a-long the line was 69.14±11.46mm;In females,such lengths were 109.83±8.99mm,32.32±4.94mm,35.77±11.26mm,and 43.75±7.62mm,respectively,with significant differences between the two gender groups(P＜0.05);In the underweight group,such distances were 119.40±12.21mm,30.72±3.83mm,25.42±7.75mm,and 65.64±14.79mm;In the normal weight group,they were 122.98±10.91mm,30.29±4.29mm,35.01±10.22mm,and 60.58±13.43mm;In the overweight group,they were 117.52±13.70mm,32.12±6.27mm,36.92±8.27mm,and 51.42±18.38mm;In the obese group,they were 120.52±13.95mm,35.65±3.29mm,29.58±11.67mm,and 60.93±15.13mm.The length of the line connecting ASIS and GT showed no statistically significant difference be-tween weight subgroups(P＞0.05).However,the length of the line intersecting with the safety zone,the length from ASIS to the safety zone along the line,and the length from GT to the safety zone along the line exhib-ited statistically significant differences between subgroups(P＜0.05).Conclusions:All the S2AI screw safety channels targets a specific area on the body surface,and the line connecting the anterior superior iliac spine and greater trochanter(GT)passes through this safety zone,which can serve as an auxiliary landmark for plac-ing the S2AI screw.

Objectives:To investigate the relationship between pelvic landmarks on body surface and the trajectory of S2 alar-iliac(S2AI)screws in populations of different genders and body mass indexes.Methods:A retrospective analysis was conducted on 150 patients who underwent pelvic CT scans in the Affiliated Hospital of Southwest Medical University between February 2022 and February 2024.Basic demographic data including age,gender,weight,and height were collected.Pelvic models were reconstructed by CT,and screw trajectories were simulated on the models.The screw trajectories were extended to intersect with the skin sur-face,and the intersection points of the safe trajectories with skin formed a safety zone on the body surface.The shortest distances from the anterior superior iliac spine(ASIS),anterior inferior iliac spine(AIIS),and greater trochanter(GT)to the safe zone were measured.The length of the line connecting ASIS and GT on the surface,length of such line intersecting with the safety zone,length from ASIS to the safety zone along such line,length from GT to the safety zone along such line were measured.Group comparisons were performed based on gender and BMI[underweight group(BMI＜18.50kg/m2),normal group(18.50kg/m2≤BMI＜24.00kg/m2),overweight group(24.00kg/m2≤BMI＜28.00kg/m2),obese group(BMI≥28.00kg/m2)].Results:In males,the shortest distances from ASIS,AIIS,and GT to the safe zone were 19.87±3.66mm,33.66±3.33mm,and 39.53±3.56mm,respectively;In females,they were 19.31±3.41mm,33.23±3.45mm,and 38.74±3.23mm,respectively.No statis-tically significant differences were observed between gender groups(P＞0.05).The shortest distance from ASIS,AIIS,GT to safety zone was 14.03±1.64mm,26.79±1.15mm,43.68±1.32mm in the underweight group,17.67±2.36mm,31.73±1.77mm,41.18±2.43mm in the normal group,21.85±1.37mm,35.78±1.76mm,36.80±1.68mm in the overweight group,and 25.66±0.84mm,38.75±0.88mm,and 36.80±1.68mm in the obese group,respec-tively.Intergroup comparisons between the four groups were statistically significant(P＜0.05),and pairwise com-parisons within groups were statistically significant(P＜0.05).In males,the length of the line connecting ASIS and GT was 129.43±6.42mm,the length of the line intersecting with safety zone was 30.72±5.27mm,the length from ASIS to safety zone along the line was 33.61±8.82mm,and the length from GT to safety zone a-long the line was 69.14±11.46mm;In females,such lengths were 109.83±8.99mm,32.32±4.94mm,35.77±11.26mm,and 43.75±7.62mm,respectively,with significant differences between the two gender groups(P＜0.05);In the underweight group,such distances were 119.40±12.21mm,30.72±3.83mm,25.42±7.75mm,and 65.64±14.79mm;In the normal weight group,they were 122.98±10.91mm,30.29±4.29mm,35.01±10.22mm,and 60.58±13.43mm;In the overweight group,they were 117.52±13.70mm,32.12±6.27mm,36.92±8.27mm,and 51.42±18.38mm;In the obese group,they were 120.52±13.95mm,35.65±3.29mm,29.58±11.67mm,and 60.93±15.13mm.The length of the line connecting ASIS and GT showed no statistically significant difference be-tween weight subgroups(P＞0.05).However,the length of the line intersecting with the safety zone,the length from ASIS to the safety zone along the line,and the length from GT to the safety zone along the line exhib-ited statistically significant differences between subgroups(P＜0.05).Conclusions:All the S2AI screw safety channels targets a specific area on the body surface,and the line connecting the anterior superior iliac spine and greater trochanter(GT)passes through this safety zone,which can serve as an auxiliary landmark for plac-ing the S2AI screw.

Objective:To evaluate the efficacy of ultrasound-guided semispinalis capitis plane (SCP) block for treatment of occipital neuralgia (ON).Methods:This was a prospective study. Ninety patients of both sexes, aged 29-66 yr, suffering ON for 3 months-6 yr in Zibo Municipal Hospital from January 2022 to December 2023, were divided into 3 groups ( n=30 each) using a random number table method: combination of greater occipital nerve (GON) block and the third occipital nerve (TON) block group (group GT), SCP block via the medial head of semispinalis capitis muscle (SCM) group (group Sm), and SCP block via the space between obliquus capitis inferior and C 2, 3 facet joint (OCI-C 2, 3) group (group OC). In GT group, the analgesic and anti-inflammatory compound solution 2.5 ml was injected around GON in the SCM-OCI space at the C 2 level of the cervical vertebra and at the lateral surface of C 2, 3 facet joint. In Sm group, the analgesic and anti-inflammatory compound solution 5 ml was injected into the medial head of SCM at the level of C 1. In OC group, the analgesic and anti-inflammatory compound solution 5 ml was injected into the OCI-C 2, 3 space in the deep part of SCM. The Visual Analogue Scale (VAS) score and Pittsburgh Sleep Quality Index (PSQI) score were recorded before treatment (T 1) and at 1, 3, 7, 10 and 14 days after treatment (T 2-6), and then the rates of pain relief and improvement in sleep quality were calculated. The time spent in blocking, onset time of blocking, completion time of blocking, duration of block, and occurrence of adverse reactions within 24 h after block were recorded. Results:There were no significant differences in VAS scores and PSQI scores at T 1-3 and T 5-6 among the three groups ( P>0.05), and VAS and PSQI scores were significantly higher at T 4 in Sm group than in OC and GT groups ( P<0.05). Compared with GT group, the time spent in blocking was significantly shortened, the onset time and completion time of block was prolonged, and the duration of block was shortened in Sm group, and the time spent in blocking was significantly shortened, the onset time and completion time of block was shortened ( P<0.05), and no significant change was found in the duration of block in OC group ( P>0.05). No severe complications were observed in the three groups. Conclusions:Compared with the combination of GON and TON blocks, ultrasound-guided SCP block for treating ON is simple and highly safe, SCP block via the OCI-C 2, 3 space has rapid onset and long duration, leading to significant improvements in pain and sleep quality, and it can be used as the first-choice block method for treating ON.

BACKGROUND:As a routine method after lumbar spine surgery,a drainage tube is convenient for postoperative bleeding drainage and management,and there is still no consensus on the choice of postoperative removal time for short-segment lumbar spine surgery with less risk. OBJECTIVE:To explore the effect of different drainage times on early clinical efficacy after short-segment lumbar fusion. METHODS:A prospective randomized controlled study was performed on 220 patients in the Affiliated Hospital of Southwest Medical University who underwent posterior lumbar interbody fusion for lumbar degenerative diseases from March 2017 to April 2021.According to the different drainage times,the patients were randomly divided into removal on the second day after operation(group A),removal on the third day after operation(group B),and removal after the observation method 24-hour drainage volume<30 mL(group C).The perioperative indicators and follow-up results of the three groups of patients were observed and compared. RESULTS AND CONCLUSION:(1)Because 7 patients were lost to follow-up,2 patients were excluded,and 211 patients were finally included(72 patients in group A,71 patients in group B,and 68 patients in group C).(2)The average drainage time of group C was 2.91 days.The postoperative drainage volume in group A was significantly less than that in groups B and C,and the difference was statistically significant(P<0.05).On day 3 after operation,the hematocrit value of group C was lower than that of group A and group B,and the difference was statistically significant(P<0.05).Postoperative activity time and hospital stay in group A were shorter than those in groups B and C,and the difference was statistically significant(P<0.05).(3)Four patients in group A,two patients in group B and three patients in group C received an allogeneic blood transfusion.There was no significant difference among the groups(P>0.05).(4)In terms of postoperative complications,there were no statistical differences in postoperative wound leakage and surgical site infection in all three groups(P>0.05).(5)All patients were followed up for more than 12 months.Visual analog scale score and Oswestry dysfunction index of the three groups of patients before discharge and at the last follow-up were significantly improved compared with those before surgery(P<0.05).There was no statistical significance among the groups(P>0.05).(6)It is indicated that the removal of the drainage tube on the second day after a posterior lumbar fusion can effectively reduce the time to get out of bed and hospital stay,without increasing the postoperative blood loss and the risk of complications.

BACKGROUND:Some patients with cervical spondylosis have not been fully corrected sagittal position balance after cervical surgery,and this continuous sagittal position imbalance may be an important reason for the poor long-term clinical outcome of patients. OBJECTIVE:To analyze the correlation between the cervical sagittal position balance parameters and their changes and the clinical efficacy of patients in the unbalanced state after anterior cervical decompression and fusion and to explore the necessity of surgical correction of sagittal balance in order to improve the clinical effect in the later stage. METHODS:A retrospective analysis was performed on 125 patients with cervical spondylosis who underwent anterior cervical decompression and fusion in the Department of Spinal Surgery of Affiliated Hospital of Southwest Medical University from July 2019 to July 2022.Follow-up patients had good postoperative recovery(neck disability index score less than 10%one week after surgery)and had complete follow-up data.According to the axial vertical distance(C2-7 SVA)in sagittal position one week after surgery,patients were divided into type I imbalance group(C2-7 SVA loss≤5 mm,n=27),type Ⅱ imbalance group(C2-7 SVA loss>5 mm,and≤10 mm,n=19),and type Ⅲ imbalance group(C2-7 SVA loss>10 mm,n=12),and non-unbalanced group(C2-7 SVA in the normal range,n=67).The changes of visual analog scale score and neck disability index were compared among groups postoperatively and the last follow-up,as well as the changes of imaging sagittal balance parameters C2-7 cobb angle,C2-7 SVA value,neck inclination angle,T1 inclination angle,and thoracic entrance angle.The correlation between the late clinical effect and postoperative cervical sagittal disequilibrium was explored. RESULTS AND CONCLUSION:(1)There was no statistical difference in general data among the four groups(P>0.05).All patients underwent successful surgery without serious complications and postoperative wound infection.The follow-up time was more than 1 year.(2)There was no significant difference in preoperative symptom score and clinical efficacy one week after surgery(P>0.05).At the last follow-up,pain visual analog scale score,neck disability index and C2-7 SVA were lower than those before surgery but higher than those one week after surgery(P<0.05).C2-7 cobb angle was increased compared with those before operation(P<0.05).T1 inclination angle was decreased compared with those before operation(P<0.05).(3)Pearson correlation test showed that the change of neck disability index was positively correlated with the change of C2-7 SVA(P<0.05).(4)It is indicated that anterior cervical decompression and fusion is effective in the treatment of cervical spondylosis,and can effectively relieve the symptoms of patients.Patients with more severe cervical sagittal disequilibrium after surgery had worse curative effect in the later period.Continuous sagittal disequilibrium in patients with cervical spondylosis after surgery is an important cause of poor curative effect in the later stage.Clinicians should pay more attention to the correction of cervical sagittal balance before and during surgery,formulate surgical strategies and plans according to sagittal balance parameters before surgery,and correct C2-7 SVA intraoperatively to the normal range.

Objectives:To explore the clinical effects of one-stage posterior approach via multifidus-longis-simus cleavage planes for lesion debridement,bone grafting and internal fixation in the treatment of thora-columbar suppurative spondylitis in adults.Methods:73 patients with thoracic or lumbar pyogenic spondylitis who underwent one-stage posterior approach via multifidus-longissimus cleavage planes for lesion removal and bone grafting and internal fixation in the Department of Orthopedics,the Affiliated Hospital of Southwest Medical University from February 2019 to February 2021 were retrospectively analyzed.There were 52 males and 21 females,aged 35-75 years(56.5±10.7 years);T1-T10 in 15 cases,T11-L2 in 32 cases,and L3-L5 in 26 cases.Obvious kyphotic deformity was found locally in all the patients.23 cases were accompanied with intraspinal epidural abscess,and 17 cases with paravertebral or psoas major muscle abscess.7 cases were combined with neurological impairment,and the American Spinal Injury Association(ASLA)classification of neurological function was detailed in 1 case of grade C and 6 cases of grade D.24 cases were complicat-ed with cardiovascular and cerebrovascular diseases,35 cases with diabetes,and 30 cases had a history of invasive operation.The venous blood was collected for bacterial culture before operation.All the patients were treated with one-stage posterior approach via multifidus-longissimus cleavage planes for lesion removal and bone grafting and internal fixation.The lesion tissue was taken for bacterial culture during operation.The postoperative irrigation lasted for 10-14d,and the anti-infection treatment lasted for 6-8 weeks.The operative time,intraoperative blood loss,and length of hospital stays,and complications were recorded;Erythrocyte sedimentation rate(ESR),C-reactive protein(CRP)and procalcitonin(PCT)were compared preoperatively and be-fore discharge;Visual analogue scale(VAS)scores of thoracolumbar back pain before operation and discharge and at final follow-up were compared.The Cobb angles of kyphosis of the lesion segment were measured on radiographs,and the rate of correction of kyphosis and loss angle of correction at the final follow-up were calculated;The recovery of spinal cord function(ASIA grade)and bone graft fusion at final follow-up were ob-served and evaluated.Results:All the patients underwent the surgery successfully.The operative time was 195.8±15.5min,the intraoperative blood loss was 562.1±45.5mL,and the length of hospital stays were 18.0±2.0d.Postoperative complications occurred in 9 patients(12.3％):2 patients had delirium syndrome,which gradually disappeared after oral administration of olanzapine;4 cases had lower limb pain and numbness,and the symptoms disappeared after nutritional nerve treatment;3 cases presented with pleural effusion and were cured after administration of closed chest drainage,anti-infection and strengthening of lung function exercises.51 cases were positive of bacterial culture,including 29 cases of Staphylococcus aureus,17 cases of Es-cherichia coli and 5 cases of Staphylococcus epidermidis.Preoperative ESR,CRP and PCT were 80.9±13.9mm/h,58.4±13.5mg/L,0.8±0.2ng/mL,and before discharge they were 29.6±8.9mm/h,15.0±7.2mg/L and 0.1±0.0ng/mL.ESR,CRP,and PCT were significantly decreased before discharge compared with preoperative values(P＜0.05).The patients were followed up for 12-30 months(20.1±4.0 months).At preoperation,before dis-charge and final follow-up,the VAS scores were 7.6±1.1,2.2±0.6 and 1.6±0.6,respectively.Before discharge and final follow-up VAS scores were significantly lower than the preoperative score(P＜0.05).The Cobb angle was 19.6°±1.6°,6.2°±1.5°,9.4°±1.0°,and the correction angle was 13.4°±0.6°,the correction rate was 68.7％±5.3％,which was significantly corrected before discharge(P＜0.05).At final follow-up,the corrected angle loss was 3.2°±0.7° relative to before discharge,and the corrected angle loss rate was 24.0％±4.6％(P＜0.05).At the final follow-up,one patient of preoperative ASIA grade C recovered to grade D,and six patients of grade D recovered to grade E.There was no change in ASLA grade after operation in patients without nerve injury before operation.Bone fusion was achieved in all patients at the final follow-up.Conclusions:On the basis of anti-infection,one-stage posterior approach via multifidus-longissimus cleavage planes for the treatment of thoracolumbar suppurative spondylitis enables removal of lesion,decompression of spinal canal,and fusion and fixation of intervertebral support implants with protection of paravertebral muscles as well as the posterior lig-amentous complexes,and reduces chronic thoracolumbar back pain after operation.

Objective:To observe the anatomical characteristics of the semispinalis capitis plane (SCP) to provide a reference for clinically effective implementation of ultrasound-guided SCP block.Methods:Ultrasound scanning was performed in six certain districts of SCP in 30 healthy volunteers (60 sides). The key point was to examine and describe the anatomical characteristics of semispinalis capitis (SCA), deep space of SCA and structures within the space.Results:(1) Transverse scanning at the posterior arch of atlas revealed that the SCA was separated into medial and lateral head by an oblique thick septum; in the space between SCA and obliquus capitis inferior (SCA-OCI), the third occipital nerve (TON) and the greater occipital nerve (GON) were separated by a fascia.There was often a branch of occipital vein between them.The distance from TON to GON was (12.9±0.6) mm.(2) Transverse scanning at the lamina of axis revealed that the axial image of SCA and the structures in SCA-OCI space were similar to the results previously described in (1). The distance from TON to GON was (12.1±0.5) mm.(3) Sagittal scanning beside the spinous process of axis revealed that SCA was separated into superior and inferior belly by a septum which connected to the end of axis spinous process.(4) Sagittal scanning at the C 2, 3 facet joint revealed that in the space between OCI and C 2, 3 facet joint (OCI-C 2, 3) beneath SCA, there was no septum between TON and GON.The distance from TON to GON was (8.0±0.5) mm.(5) Transverse scanning at the lamina of C 4 revealed that in the space between SCA and semispinalis cervicis, the deep cervical artery and vein were observable except medial branch of C 4, and the characteristics of the short axis of the SCA belly were similar to the results previously described in (1). (6) Transverse scanning at the lamina of C 5 revealed that the view was similar to the results previously described in (5). The posterior branch of C 5 nerve was not found. Conclusions:SCP is rich in fascia, and blood vessels often pass through the deep surface space of SCA under ultrasound.The anatomical structure is complex, and there is individual variation.Grasping its ultrasonic anatomical characteristics is helpful in safely and effectively implementing ultrasound-guided SCP block.

Objective:To investigate the clinical value of short segment fusion and long segment fusion combined with posterior pedicle screw system internal fixation in the treatment of degenerative scoliosis.Methods:74 patients with degenerative scoliosis who were treated in the Affiliated Hospital of Southwest Medical University from January 2014 to February 2018 were enrolled in the study. The patients were divided into group A and group B with a random number table of 37 cases each. Group A was treated with short segment fusion and posterior pedicle screw system internal fixation, while group B was with long segment fusion and posterior pedicle screw system internal fixation. The Cobb angle of scoliosis, the balance of coronal and sagittal plane of spine were observed before operation, 1 week after operation, 3 months after operation and 6 months after operation, and the incidence of early and long-term complications were counted.Results:The Cobb angle of scoliosis in group B was lower than that of group A at 1 week, 3 months and 6 months after operation ( P<0.05). There was no significant difference in the balance of coronal plane and sagittal plane between the two groups at 1 week and 3 months after operation ( P>0.05). There was significant difference in the balance of coronal plane and sagittal plane between the two groups at 6 months after operation ( P<0.05). There was no significant difference in the incidence of early postoperative complications between the two groups ( P>0.05). Conclusions:Long segment fusion and posterior pedicle screw system internal fixation can improve the Cobb angle and reduce the incidence of postoperative scoliosis, but it is easy to appear the imbalance of coronal and sagittal planes, which can be selected according to the actual situation.

OBJECTIVETo investigate the infection status and virulent genes of Aeromonas in patients with acute diarrhea in Pudong New Area, Shanghai.

METHODSIn 2012, stool samples were collected from diarrhea patients in 12 sentinel hospitals in Pudong for the detections of 13 pathogens causing diarrhea, and the detections of 5 diarrhea related virulent genes were conducted for Aeromonas isolates.

RESULTSA total of 101 patients were infected with Aeromonas in 2533 patients (4.0%). A total of 101 Aeromonas strains were isolated, including 17 Aeromonas hydrophila strains (18.8%), 44 Aeromonas veronii biovar sobria strains (52.5%) and 12 Aeromonas caviae strains (29.7%). And 44 coinfections with other pathogens were detected. Aeromonas infection mainly occurred in summer and in people aged ≥20 years. Among the patients infected with Aeromonas, 71 (70.3%) had watery diarrhea, 20 (19.8%) had vomiting and 11 (10.9%) had fever. Virulent genes detection showed that 95.0% of the Aeromonas. strains carried virulent genes, and the detection rates of hlyA, aerA, act, alt, and ast genes were 5.9%, 6.9%, 67.3%, 42.6% and 13.9%, respectively.

CONCLUSIONSHigh incidence of Aeromonas infection was found in the patients with acute diarrhea in Pudong, and a high proportion of coinfections with other pathogens was detected too. Most Aeromonas strains carried virulent genes, and the distribution varied.

Aeromonas ; genetics ; Aeromonas hydrophila ; genetics ; China ; epidemiology ; Diarrhea ; microbiology ; Gram-Negative Bacterial Infections ; epidemiology ; microbiology ; Humans ; Seasons ; Virulence ; genetics ; Young Adult