ABSTRACT
Bacterial biofilms(BF)are complex microbial communities formed by bacteria on living or abiotic surfaces.Their formation significantly enhances bacterial virulence and drug resistance and is associated with a high proportion of chronic bacterial infections,posing a serious threat to human health.The ability of traditional antibiotics and commonly used disinfectants to clear biofilms is limited,and an effective new strategy to treat BF is urgently needed.Bacteriophage,as a kind of virus that can infect and lyse bacteria,has high safety and specificity,and is considered as a promising alternative method for the treatment of BF.In this paper,the mechanism of bacteriophage anti-bacterial biofilm and the application strategies based on bacteriophage and its derivatives in the prevention and control of bacteriophage biofilm formation were reviewed,which provided new ideas for the development of efficient bacteriophage anti-bacterial biofilm methods.
ABSTRACT
Objective To establish a Nomogram model for assessing the risk of intestinal colonization by Carbapenem-Resistant Klebsiella pneumoniae(CRKP)to determine the specific probability of colonization and adopt individualized prevention strategies for the purpose of reducing the occurrence of colonization and secondary infection of neonatal CRKP.Methods A total of 187 neonates hospitalized between January 2021 and October 2022 and diagnosed with CRKP colonization by rectal swab/fecal culture as well drug sensitivity identification 48 h after admission were assigned to the CRKP group.Another 187 neonates without non-CRKP colonization during the same period were set as the non-CRKP group.All the data of the two groups were used for a retrospective analysis.The caret package in R 4.2.1 was used to randomly divide the 374 cases into the model group and validation group at a ratio of 3∶1.Then the glmnet package in R 4.2.1 was used to conduct a LASSO regression analysis over the data from the model group to determine the predictive factors for modeling and the rms software package was used to build a Nomogram model.The pROC and rms packages in R 4.2.1 were used to examine the data,analyzing the consistency indexes(Cindex),receiver operating characteristic curves(ROC),and area under the curves(AUC)and performing the internal and external validation of the efficacy of the Nomogram model via the calibration curves.Results LASSO regression analysis determined eight predictors from the 35 factors probably affecting neonatal CRKP colonization:gender,cesarean section,breastfeeding,nasogastric tube,enema,carbapenems,probiotics,and hospital stay.The Nomogram model constructed using these eight predictors as variables could predict CRKP colonization to a moderate extent,with the area under the ROC curve of 0.835 and 0.800 in the model and validation group,respectively.The Hos-mer-Lemeshow test showed that the predicted probability was highly consistent with the actual probability(the modeling group:P = 0.678>0.05;the validation group:P = 0.208>0.05),presenting a higher degree of fitting.Conclusion The Nomogram model containing such variables as gender,cesarean section,breastfeeding,nasogastric tube,enema,carbapenems,probiotics,and hospital stay is more effective in predicting the risk of neonatal CRKP colonization.Therefore,preventive measures should be individualized based on the colonization probability predicted by the Nomogram model in order to keep neonates from CRKP colonization and reduce the incidence of secondary CRKP infections among them.
ABSTRACT
Objective To analyze the influencing factors for intestinal colonization and secondary infection of car-bapenem-resistant Klebsiella pneumoniae(CRKP)in neonates,and provide a basis for formulating prevention and control strategies for CRKP infection.Methods Neonates who were admitted to the neonatal ward of a hospital from January 2021 to October 2022 were selected as the study subjects,and the first screening of CRKP was con-ducted within 48 hours after admission.In addition,active anal swab screening for carbapenem-resistant Ente-robacterales(CRE)was performed weekly during hospitalization,and the infection status of CRKP strains was mo-nitored.Clinical data of neonates in the colonization group,non-colonization group,and infection group were ana-lyzed.Intestinal colonized strains and the non-repetitive CRKP strains isolated from clinical specimens of neonates with secondary infection after colonization were performed carbapenemase gene detection,multilocus sequence ty-ping(MLST)and pulsed-field gel electrophoresis(PFGE)analysis.Results A total of 1 438 neonates were active-ly screened for CRE,174 were CRKP positive,CRKP colonization rate was 12.1％.Among 174 neonates,35 were with secondary infection,with the incidence of 20.1％.The independent risk factors for neonatal CRKP intestinal colonization were cesarean section(OR=2.050,95％CI:1.200-3.504,P=0.009),use of cephalosporins(OR=1.889,95％CI:1.086-3.288,P=0.024),nasogastric tube feeding(OR=2.317,95％CI:1.155-4.647,P=0.018).Protective factors were breast-feeding(OR=0.506,95％CI:0.284-0.901,P=0.021),oral probiotics(OR=0.307,95％CI:0.147-0.643,P=0.002),and enema(OR=0.334,95％CI:0.171-0.656,P=0.001).Independent risk factors for secondary infection after intestinal colonization of neonatal CRKP were carbapenem anti-biotic use(OR=19.869,95％CI:1.778-222.029,P=0.015)and prolonged hospital stay(OR=1.118,95％CI:1.082-1.157,P＜0.001).The detection results of drug resistance genes showed that carbapenemase-producing genes of CRKP strains were all blaKPC-2,all belonged to type ST11.Homologous analysis showed that intestinal CRKP colonization was highly homologous with the secondary infection strains after colonization.Conclusion CRKP intestinal colonization during neonatal hospitalization may increase the risk of CRKP infection.Risk and pro-tective factors of neonatal intestinal colonization and secondary infections after colonization should be paid attention,and corresponding preventive and control measures should be taken,so as to reduce the occurrence and transmission CRKP healthcare-associated infection.