Nosocomial blood stream infection in intensive care units at Assiut University Hospitals (Upper Egypt) with special reference to extended spectrum β-lactamase producing organisms

<p>Abstract</p> <p>Aim</p> <p>This study investigated the nosocomial blood stream infection (BSI) in the adult ICUs in Assiut university hospitals to evaluate the rate of infection in different ICUs, causative microorganisms, antimicrobial resistance, outcome of infection, risk factors, prevalence of extended spectrum B-lactamase producing organisms and molecular typing of <it>Klebsiella pneumoniae </it>strains to highlight the role of environment as a potential source of nosocomial BSI.</p> <p>Methods</p> <p>This study was conducted over a period of 12 months from January 2006 to December 2006. All Patients admitted to the different adult ICUs were monitored daily by attending physicians for subsequent development of nosocomial BSI. Blood cultures were collected from suspected patients to detect the causative organisms. After antimicrobial susceptibility testing, detection of ESBLs was conducted among gram negative isolates. Klebsiella pneumoniae isolates were tested by PCR to determine the most common group of B-lactamase genes responsible for resistance. Klebsiella pneumoniae isolates from infected patients and those isolated from the environment were typed by RAPD technique to investigate the role of environment in transmission of infection.</p> <p>Results</p> <p>The study included 2095 patients who were admitted to different ICUs at Assiut University Hospitals from January 2006 to December 2006. Blood samples were collected from infected patients for blood cultures. The colonies were identified and antibiotic sensitivities were performed. This study showed that the rate of nosocomial BSI was 75 per 1000 ICU admissions with the highest percentages in Trauma ICU (17%). Out of 159 patients with primary bloodstream infection, 61 patients died representing a crude mortality rate of 38%. Analysis of the organisms causing BSI showed that Gram positive organisms were reported in 69.1% (n = 121); MRSA was the most prevalent (18.9%), followed by methicillin resistant coagulase negative Staphylococci (16%). Gram negative bacilli were reported in 29.1% (n = 51). In this case, <it>Klebsiella pneumoniae </it>was the most common (10.3%) followed <it>E coli </it>(8.6%). <it>Candida spp</it>. was reported only in (1.7%) of isolates. Antibiotics sensitivities of Gram positive organisms showed that these organisms were mostly sensitive to vancomycin (90.1%), while Gram negative organisms were mostly sensitive to imipenem (90.2%). In this study we tested Gram negative isolates for the production of the ESBL enzyme and concluded that 64.7% (33/51) of patients' isolates and 20/135 (14.8%) environmental isolates were confirmed to be ESBL producers. The type of β-lactamase gene was determined by polymerase chain reaction which showed that SHV was the main type. Molecular typing was done for 18 Klebsiella pneumoniae strains that caused nosocomial BSI and for the 36 Klebsiella pneumoniae strains which were isolated from the environmental samples by the RAPD method. The two environmental strains were identical, with one isolated from a patient, which confirms the serious role of the hospital environment in the spread of infections.</p> <p>Conclusion</p> <p>Nosocomial BSI represents a current problem in Assiut University Hospitals, Egypt. Problems associated with BSI include infection with multidrug resistant pathogens (especially ESBLs) which are difficult to treat and are associated with increased mortality. Of all available anti-microbial agents, carbapenems are the most active and reliable treatment options for infections caused by ESBL isolates. However, overuse of carbapenems may lead to resistance of other Gram-negative organisms.</p

Emergence of Nosocomial Pneumonia Caused by Colistin-Resistant Escherichia coli in Patients Admitted to Chest Intensive Care Unit

(1) Background: Colistin is a last-resort antibiotic used in treating multidrug-resistant Gram-negative infections. The growing emergence of colistin resistance in Escherichia coli (E. coli) represents a serious health threat, particularly to intensive care unit (ICU) patients. (2) Methods: In this work, we investigated the emergence of colistin resistance in 140 nosocomial E. coli isolated from patients with pneumonia and admitted to the chest ICU over 36 months. Virulence and resistance-related genes and E. coli pathotypes in colistin-resistant and colistin-sensitive isolates were determined. (3) Results: Colistin resistance was observed in 21/140 (15%) of the nosocomial E. coli isolates. The MIC50 of the resistant strains was 4 mg/L, while MIC90 was 16 mg/L. Colistin-resistant isolates were also co-resistant to amoxicillin, amoxicillin/clavulanic, aztreonam, ciprofloxacin, and chloramphenicol. The mechanism of colistin resistance was represented by the presence of mcr-1 in all resistant strains. Respectively, 42.9% and 36.1% of colistin-resistant and colistin-sensitive groups were extended-spectrum β-lactamase (ESBL) producers, while 23.8% and 21% were metallo β-lactamase (MBL) producers. blaTEM-type was the most frequently detected ESBL gene, while blaIMP-type was the most common MBL in both groups. Importantly, most resistant strains showed a significantly high prevalence of astA (76.2%), aggR (76.2%), and pic (52.4%) virulence-related genes. Enteroaggregative E. coli (76%) was the most frequently detected genotype among the colistin-resistant strains. (4) Conclusion: The high colistin resistance rate observed in E. coli strains isolated from patients with nosocomial pneumonia in our university hospital is worrisome. These isolates carry different drug resistance and virulence-related genes. Our results indicate the need for careful monitoring of colistin resistance in our university hospital. Furthermore, infection control policies restricting the unnecessary use of extended-spectrum cephalosporins and carbapenems are necessary

Risk Factors and Immune Response to Hepatitis E viral Infection among Acute Hepatitis Patients in Assiut, Egypt

Hepatitis E virus (HEV) infection is a common cause of acute viral hepatitis (AVH) in Egypt. We aimed to identify risk factors of HEV among acute hepatitis cases, measure HEV specific immune response to differentiate between symptomatic and asymptomatic infections. The study included symptomatic acute hepatitis (AH) patients (n=235) and asymptomatic contacts (n=200) to HEV cases. They completed a lifestyle questionnaire, screened for common hepatotropic viruses. Blood and serum samples were collected from patients and contacts after onset of disease and follow-up samples collected until convalescence. PBMC were separated and tested for specific HEV T-cell response by INFELISPOT assay. Serum samples were tested for IgM and IgG anti-hepatitis E virus by ELISA. IgM antibodies to HAV were detected in 19 patients (8.1%), 37 (15.7%) with HBV, 10 (4.3%) with HCV. HEV infection was identified in 42 (16%) patients with AVH. Of the 200 contacts, 14 (7%) had serological evidence of recent HEV asymptomatic infection, showed stronger CMI responses than HEV infected subjects (2540 ± 28 and 182 ± 389 ISCs /106 cells, respectively; P <0.05). In conclusion, HEV is a major cause of AVH in Egypt. Asymptomatic HEV patients are likely to have stronger immune responses including CMI responses, than symptomatic cases

Antimicrobial Resistance and Comparative Genome Analysis of Klebsiella pneumoniae Strains Isolated in Egypt

Klebsiella pneumoniae is an important human pathogen in both developing and industrialised countries that can causes a variety of human infections, such as pneumonia, urinary tract infections and bacteremia. Like many Gram-negative bacteria, it is becoming resistant to many frontline antibiotics, such as carbapenem and cephalosporin antibiotics. In Egypt, K. pneumoniae is increasingly recognised as an emerging pathogen, with high levels of antibiotic resistance. However, few Egyptian K. pneumoniae strains have been sequenced and characterised. Hence, here, we present the genome sequence of a multidrug resistant K. pneumoniae strain, KPE16, which was isolated from a child in Assiut, Egypt. We report that it carries multiple antimicrobial resistance genes, including a blaNDM-1 carbapenemase and extended spectrum β-lactamase genes (i.e., blaSHV-40, blaTEM-1B, blaOXA-9 and blaCTX-M-15). By comparing this strain with other Egyptian isolates, we identified common plasmids, resistance genes and virulence determinants. Our analysis suggests that some of the resistance plasmids that we have identified are circulating in K. pneumoniae strains in Egypt, and are likely a source of antibiotic resistance throughout the world

Antimicrobial resistance and gene regulation in Enteroaggregative Escherichia coli from Egyptian children with diarrhoea:Similarities and differences

Enteroaggregative Escherichia coli (EAEC) is a common diarrhoeagenic human pathogen, isolated from patients in both developing and industrialized countries, that is becoming increasingly resistant to many frontline antibiotics. In this study, we screened 50 E. coli strains from children presenting with diarrhea at the outpatients clinic of Assiut University Children's Hospital, Egypt. We show that all of these isolates were resistant to multiple classes of antibiotics and identified two as being typical EAEC strains. Using whole genome sequencing, we determined that both isolates carried, amongst others, bla CTX-M and bla TEM antibiotic resistance genes, as well as many classical EAEC virulence determinants, including the transcriptional regulator, AggR. We demonstrate that the expression of these virulence determinants is dependent on AggR, including aar, which encodes for a repressor of AggR, Aar. Since biofilm formation is the hallmark of EAEC infection, we examined the effect of Aar overexpression on both biofilm formation and AggR-dependent gene expression. We show that whilst Aar has a minimal effect on AggR-dependent transcription it is able to completely disrupt biofilm formation, suggesting that Aar affects these two processes differently. Taken together, our results suggest a model for the induction of virulence gene expression in EAEC that may explain the ubiquity of EAEC in both sick and healthy individuals

Protective role of humoral immune responses during an outbreak of hepatitis E in Egypt

Although the seroprevalence of hepatitis E virus (HEV) is approximately 80% in adult Egyp- tians living in rural areas, symptomatic HEV-caused acute viral hepatitis (AVH) is sporadic and relatively uncommon. To investigate the dichotomy between HEV infection and clini- cal AVH, HEV-specific immune responses in patients with symptomatic and asymptomatic HEV infection during a waterborne outbreak in Egypt were examined. Of 235 acute hepati- tis patients in Assiut hospitals screened for HEV infection, 42 (17.9%) were hepatitis acute hepatitis patients confirmed as HEV-caused AVH; 37 (88%) of the 42 patients were residents of rural areas, and 14 (33%) were from one village (Kom El-Mansoura). Another 200 AVH contacts of AVH cases in this village were screened for HEV and 14 (7.0%), all of whom were family members of AVH cases, were asymptomatic HEV IgM-positive. HEV infections in this village peaked during the summer. Asymptomatic HEV seroconverters had significantly higher levels of epitope-specific neutralising (p=0.006) and high avidity (p=0.04) anti-HEV antibodies than the corresponding AVH cases. In conclusion, naturally acquired humoral immune responses appear to protect HEV-exposed subjects from AVH during an HEV outbreak in Egypt