ABSTRACT
Stentrophomonas maltophila [S. maltophila] biofilm plays a crucial role in its resistance to antibiotics. Extracellular DNA found to be an essential component of biofilm of different Gram positive and Gram negative bacteria. Its role in S. maltophila biofilm is not well established. This work assessed the role of destruction of extracellular DNA of S. maltophila biofilms in enhancing the antimicrobial effect of the used levofloxacin or ciprofloxacin. This study enrolled twenty three isolates of S. maltophila in which biofilm production and the presence of extracelular DNA in it were tested. The effect of two quinolone antibiotics [ciprofloxacin and levofloxacin] and DNAase each alone and in combination together on biofilm production were assessed on biofilm production and viable count. Our results showed that combined use of DNase with either ciprofloxacin or levofloxacin caused significant reduction of both biomass and viable count. In conclusion, the addition of DNase to quinolones boosts the antibiotic efficacy against S. maltophila biofilm
ABSTRACT
Objective: The aim of this study was to detect the rate of catheter-related bloodstream infection [CRBSI] in NICU of Mansoura University Children's Hospital and to focus on possible predictors of infection. Study
Design: A cross sectional comparative study to detect rate of CRBSI among neonates with central vascular catheters during the period between January 2009 and April 2012. Then, a nested case control study done among CRBSI cases and central vascular catheters none infected as a control group to detect predictors associated with their occurrence
Patients and Methods: Blood samples were collected from III neonates clinically suspected ofsepticemia and had inserted venous line. Central, peripheral blood and catheter tip cultures were done for each case
Results: CRBSI was confirmed in 69 cases as central blood culture count was > 3 folds of peripheral blood culture count. Catheter tip culture showed > 103 CFV/ ml per catheter of the same organisms. Low birth weight, age below 7 days, prematurity, mechanical ventilation, TPN administration and prolonged hospital stay were predictors of CRBSI. Logistic regression of the studied predictors showed that birth weight, TPN administration and length of central venous catheter stay were significant predictors of CRBSI
Conclusion: CRBSI is a common problem in NICU. Predictors of CRBSI included low birth weight, prematurity and mechanical ventilation. Potential use of TPN, prolonged catheter stay and low birth weight are independent predictors for CRBSI
ABSTRACT
Background and objectives: Accurate identification of neonatal sepsis is an increasing problem facing neonatologists due to non specific clinical signs with no existing single reliable marker of infection. Molecular assays for the detection of bacterial DNA in the blood represent possible diagnostic tools for early identification of bacterial causes. Procalcitonin [PCT] is a promising marker distinguishing between infection and inflammation which cannot be differentiated by acute phase proteins as C-reactive protein [CRP]. The aim of the study was to compare results of blood cultures with eubacterial PCR, PCT and CRP as early markers of neonatal sepsis
Subjects and methods: In this study, neonates with clinically suspected sepsis admitted to neonatal intensive care unit [NICU] in Mansoura University Children Hospital were included. Based on blood culture positive results, they were divided into 2 groups: proven sepsis and clinical sepsis. Comparing the 2 groups, sensitivity and specificity for, PCR, PCT and CRP were evaluated. Using receiver operating characteristic [ROC] curves, threshold value for both PCT and CRP were estimated
Results: Out of 141 neonates with clinically suspected sepsis, 56 (39.7%) were confirmed as proven sepsis. Compared to blood culture, the diagnosis of bacterial proven sepsis by PCR revealed 100 % sensitivity and 93% specificity. This study revealed that PCT >6.5 ng/ml had 83.9% sensitivity and 98.8% specificity, whereas CRP >3.5 mg/dl had 83.9%, sensitivity and 8l.2%specificity for diagnosing sepsis
Conclusion: This study confirms the value of PCR and PCT as rapid diagnostic tools for early detection of neonatal sepsis?
ABSTRACT
Background: Early diagnosis and treatment are important in prevention of tuberculosis [TB] infection. Recently, many new strategies are validated for diagnosis and monitoring of pulmonary TB cases
Objective: To evaluate the role of Quantiferon-TB Gold in Tube test [QFT-GIT] and y9/32 T cells percentage in diagnosis of pulmonary TB and as tools to monitor the efficacy of anti-tuberculosis treatment
Methods: Two groups [40 patients and 15 healthy control] were enrolled in this study from July, 2009 to February, 2011. Both groups were evaluated by tuberculin skin test [TST], QFT-GIT assay, and y9/d2 T cells byflowcytometry. QFT-GIT assay, and y 9/82 T cells by flowcytometry were done twice for the pulmonary TB patients, first at the start of treatment and second after Smonths of treatment
Results: Among the forty proved pulmonary TB cases, 31[77.5%] cases were only positive for acid-fast bacilli [AFB] smear. Meanwhile, 31[82.5%] cases were positive by TST with specificity and sensitivity of 82.5% and 40% respectively in comparison to 37[92.5%] patients showedpositivity by QFT-GIT assay "tviih specificity and sensitivity of 92.5% and 93.5% respectively. Regarding, the 27 clinically improved pulmonary TB patients, 10 cases turned negative for QFT-GIT after 3 month course of antituberculous treatment. Moreover, Quantitative QFT-G level fall significantly in active tuberculosis patients undergoing treatment [p <0.05]. Whereas, the mean percentage of y 9/62 T declined mildly from 1.31 %to 1.03 % at the start and after 3 months of treatment respectively [P >0.05].Also, it -was noted that the mean percentage ofy9/d2 T decrease with the severity of the disease, 0.36%, 1.37% and 1.57% in stage 3, 2 andl respectively
Conclusion: QFT-GIT assay is a potent immnnodiagnostic test for pulmonary TB but it may not afford enough level of feasibility regarding cure of infection. However, the pretreatment concentration of IFN-y correlates to reversion to negative QFT-GIT. In addition, y9/62 T cells percent which had limited value to monitor the efficacy of anti-TB treatment but these cells could be used to assess the severity of the disease?
ABSTRACT
Background and objectives: typing of Meticillin-resistant Staphylococcus aureus [MRSA] is of great importance for detection of the relatedness of isolate. Both phenotypic and genotypic markers can be employed to type MRSA strains. The spa gene encoding protein A and the CoA gene encoding coagulase enzyme contain highly polymorphic repeat units. These repeats allowed for differentiation between MRSA isolates that are heterogeneous in respect to these regions using polymerase chain reaction - restriction fragment length polymorphism [PCR - RFLP] assay. This study aimed to address the competence of various typing methods [antibi typing, coa gene typing and spa gene typing] in discriminating MRSA isolates and to assess the concordance between the used typing methods
Material and Methods: this study included, 61 nosocomial MRSA isolates collected from different clinical wards of Mansoura University Hospitals between December 2009 and September 2010. They were analyzed by antibiotic resistance profile and PCR - RFLP of both CoA and spa genes after Alu- I and Rsa -I restriction enzymes digestion respectively. The discrimination index [D] and concordance were calculated
Results: the power of discrimination among MRSA isolates as estimated by the discrimination index increased orderly from antibi typing [D = 0.69], spa gene typing [D = 0.74] to CoA gene typing [D = 0.82] yielding 8, 5 and 6 types respectively. Combination of the 3 typing methods offered the highest D of 0.98. Coa gene typing was more concordant with spa gene typing, while the concordance between antibi typing and each of Coa and spa typing was the same
Conclusion: we concluded that, CoA typing demonstrated the most effective discrimination of MRSA isolates, while grouping of isolates based on combining the 3 typing methods provided the highest discrimination. So, CoA and spa genetic typing methods could be used in routine epidemiological surveillance in association with antibi typing as daily screening test which is very beneficial to develop efficient infection control measures in hospitals
ABSTRACT
Background: nosocomial urinary tract infection [NUTI] is the most common infections in intensive care unit [ICU] with a considerably high mortality and morbidity rates. It is a cause of concern and major pool of resistant pathogens
Objective: this is a prospective study conducted to detect the frequency of NUTI, common microorganisms, the risk factors and mortality in neurological ICU [NICU] at Mansoura University Hospital
Patients and methods: the current study enrolled patients who were admitted to NICU for >/=48 hrs. From August 2009 to Sept 2010. Three hundred ninety-six patients [190 males and 206 females with median age 60 years] were enrolled in the present work NUTI were diagnosed according to the CDC definition for patients who had urinary catheters. The following risk factors, age, sex, length of stay, duration of catheterization, immuno-compromised and risk of mortality, were studied. As well, isolation, identification and antimicrobial susceptibility were performed. An Enterobacter cloacae outbreak of UTI was detected. Typing and tracing of the source of infection was confirmed using ERIC-PCR
Results: NUTI frequency rate was 20.5%. The NUTI rate were high among old age, female, prolonged hospitalization, catheterization and immunocompromised patients. The mortality rate among NUTI patients was not significantly high. E. coli was the most common isolate [27.3%] which had maximum sensitivity to amikacin followed by meropenem. ERIC showed the same banding patterns among isolates from the three patients and hands of a nurse who was considered as the source of the outbreak
Conclusion: prevention of NUTI clearly represents a real challenge that faces the health care field especially in ICUs. No doubt, effective interventions will be a critical step in the battle against antibiotic resistance and outbreak emergence in ICUs
ABSTRACT
Background: Peritoneal tuberculosis [PTB] is an unusual cause of ascites in developed countries but it is a considerable problem in developing countries. The advance and validation of new diagnostic strategies are precedence for tuberculosis control programs
Objective: To probe the effectiveness of adenosine deaminase [ADA] activity and QuantiFERON TB Gold In-tube [IT] for diagnosis of PTB
Materials and Methods: Forty one patients were enrolled from Feb. 2007 to Jan. 2010 with a presumptive diagnosis of tuberculous peritonitis with ascites at Mansoura University Hospitals. The ascitic fluid was examined biochemically [protein content], cytologically [WBCs count] and microbiologically [ZN stain and TB culture on Lowenestien-Jensen media]. The level of ADA was determined in ascetic fluid samples. Interferon [IFN] - gamma of whole blood was assayed by QuantiFERON TB Gold [IT] ELISA test
Results: Fourteen [34.14%] patients were diagnosed as TB peritonitis according to pre-determined definition criteria. Three [21.4%] cases were positive for acid-fast bacilli [AFB] smear with 21.4% detection sensitivity and 100% specificity. Mycobacterium tuberculosis [MTB] cultures were positive in 8 patients with a detection sensitivity of 57.1% and 100% specificity. Using Receiver operating characteristics [ROC] curve, a cut-off level of 35 IU/L for the diagnosis of TB peritonitis by ADA was found to have the best results with corresponding sensitivity, specificity, positive predictive value [PPV] and negative predictive value [NPV] of 100%, 92.6%, 87.5% and 100% respectively. Thirteen [92.85%] out of 14 TB peritonitis patients were positive for QuantiFERON-TB Gold [IT] assay. The only negative case was TB culture positive and AFB-smear negative. The sensitivity and specificity of PPV and NPV assay were 92.9%, 100%, 100% and 96.4% respectively
In conclusion: the use of these rapid tests with enough discriminatory power gives a chance for initiation of treatment while waiting for the results of MTB culture
ABSTRACT
Background and objectives: acinetobacter baumannii [A. baumannii] septicemia is an important cause of morbidity and mortality in neonates hospitalized in neonatal intensive care units [NICUs]. The difficulty of treating A. baumannii nosocomial infection is associated with the high resistance to a wide range of antimicrobial agents. We aimed to find the role of A. baumannii as a nosocomial pathogen causing neonatal septicemia with special concern on risk factors for their acquisition and metallobetalactamases [MBLs] production, aiming to implement infection control program and treat infections
Material and Methods: this study was conducted over 22 month period and included 272 neonates with suspected septicemia admitted to NICU, Mansoura University Children's Hospital. Blood samples were cultured from all cases. A. baumannii identification, susceptibility testing and MBL production using double-disc synergy test [DDST] and combined-disc test [CDT] were performed. Multiplex polymerase chain reaction [PCR] assay was done to detect and differentiate the five families of acquired MBL genes IMP, VIM, SPM, GIM and SIM in a single reaction
Results: A. baumannii was detected in 23/272 [8.45%]. Associated risk factors included low birth weight, the use of central venous catheters, mechanical ventilation and prior antibiotics use. Case fatality rate was 6/23[26.1%]. Resistance to imipenem was 8/23 [34.78%]. Resistance to other antimicrobials was 7[30.4%] meropenem, 12[52.17%] piperacillintazobactam, 11[47.8%] tobramycin, 18[78.26%] ceftazidime and 13[56.52%] ciprofloxacin. Of 8 imipenem-resistant isolated clinical strains 3[37.5%] and 2 [25%] were positive for MBL production by DDST and CDT respectively. PCR analysis revealed the presence of blaVIM gene in 1 [12.5%] isolate and blaIMP gene in 3 [37.5%] isolates. No imipenem-resistant A. baumannii isolates that harbored bla SPM, SIM or bla GIM were detected. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value for DDST were 75% , 100% , 88% , 100% and 80% respectively and for CDT, they were 50% , 100% , 75% , 100% and 66.7% respectively. Interestingly, 1 [6.7%] imipenem sensitive isolate was positive MBL producer as harboring blaIMP gene by PCR
Conclusion: MBL producing A. baumannii prevalence is considerable and alarming in NICU and is associated with significant infant fatality. We recommend the consistent and constant surveillance of such strains for the amendment of empirical antimicrobial therapy and probably the reduction of mortality rates for neonates infected with MBL- producing isolates and avoiding the intra-hospital dissemination of such strains