Doaa Ghaith

Prevalence of extensively drug-resistant gram negative bacilli in surgical intensive care in Egypt

Introduction The prevalence of extensively drug resistant gram negative bacilli (XDR-GNB) is rapidly progressing; however in Egypt data are sparse. We conducted the present study to quantify the incidence, risk factors and outcome of patients harboring XDR-GNB. Methods A one year prospective study was done by collecting all the bacteriological reports for cultures sent from the surgical intensive care unit, Cairo university teaching hospital. XDR-GNB were defined as any gram negative bacilli resistant to three or more classes of antimicrobial agents. Patients with XDR-GNB compared with those sustaining non extensively drug-resistant infection. A multivariate logistic regression model was created to identify independent predictors of multi-resistance. Results During one-year study period, a total of 152 samples (65%) out of 234 gram negative bacilli samples developed extensively drug resistant infection. XDR strains were significantly higher in Acinetobacterspp (86%), followed by Pseudomonas (63%), then Proteus (61%), Klebsiella (52%), and E coli (47%). Fourth generation cephalosporine (Cefipime) had the lowest susceptibility (10%) followed by third generation cephalosporines (11%), Quinolones (31%), Amikacin (42%), Tazobactam (52%), Carbapinems (52%), and colistin (90%). Relaparotomy was the only significant risk factor for acquisition of XDR infection. Conclusion Extensively drug-resistant gram negative infections are frequent in our ICU. This is an alarming health care issue in Egypt which emphasizes the need to rigorously implement infection control practices.

Mutations affecting domain V of the 23S rRNA gene in Helicobacter pylori from Cairo, Egypt

Background: Clarithromycin is a main component of the recommended first-line triple therapy for Helicobacter pylori in Egypt. We aimed in our study to investigate the prevalence of clarithromycin-resistant H. pylori strains due to the point mutations at domain V of the H. pylori 23S rRNA among the Egyptian population using the polymerase chain reaction/restricted fragment length polymorphism (PCR/RFLP) assay. Methods: Gastric biopsies obtained from 100 dyspeptic patients who consecutively attended at Cairo University Hospital during the period from January to November 2013 were subjected to PCR/RFLP in order to detect the point mutations at domain V of the H. pylori 23S rRNA associated with clarithromycin resistance. The PCR amplicon of the 23S H. pylori rRNA is restricted with MboII for detection of A2142G mutation and with BsaI for A2143G mutation. Results: The prevalence of H. pylori infection among 100 patients was 70%; clarithromycin resistance was detected in 39/70 (57.7%) of positive H. pylori isolates. Occurrence of 23S rRNA A2142G mutations resulted in two DNA fragments (418 and 350 bp) by PCR-RFLP; on the other hand, no A2143G mutations were detected. Conclusions: The high prevalence of clarithromycin resistance (57.7%) caused by A2142G mutations at domain V of the H. pylori 23S rRNA may mandate changing of the standard clarithromycin-containing triple therapy. The PCR/RFLP assay was a rapid and accurate method for molecular detection of H. pylori infection in addition to determination of different nucleotide mutations causing clarithromycin resistance.

Diagnostic values of CD64, C-reactive protein and procalcitonin in ventilator-associated pneumonia in adult trauma patients: a pilot study.

Abstract Background: Ventilator-associated pneumonia (VAP) is one of the most common nosocomial infections; however, its diagnosis remains difficult to establish in the critical care setting. We investigated the potential role of neutrophil CD64 (nCD64) expression as an early marker for the diagnosis of VAP. Methods: Forty-nine consecutive patients with clinically suspected VAP were prospectively included in a single-center study. The levels of nCD64, C-reactive protein (CRP), and serum procalcitonin (PCT) were analyzed for diagnostic evaluation at the time of intubation (baseline), at day 0 (time of diagnosis), and at day 3. The receiver operating characteristic curves were analyzed to identify the ideal cutoff values. Results: VAP was confirmed in 36 of 49 cases. In patients with and without VAP, the median levels (interquartile range, IQR) of nCD64 did not differ either at baseline [2.4 (IQR, 1.8–3.1) and 2.6 (IQR, 2.3–3.2), respectively; p=0.3] or at day 0 [2 (IQR, 2.5–3.0) and 2.6 (IQR, 2.4–2.9), respectively; p=0.8]. CRP showed the largest area under the curve (AUC) at day 3. The optimum cutoff value for CRP according to the maximum Youden index was 133 mg/dL. This cutoff value had 69% sensitivity and 76% specificity for predicting VAP; the AUC was 0.73 (95% CI, 0.59–0.85). The nCD64 and PCT values could not discriminate between the VAP and non-VAP groups either at day 0 or day 3. Conclusions: The results of this pilot study suggest that neutrophil CD64 measurement has a poor role in facilitating the diagnosis of VAP and thus may not be practically recommended to guide the administration of antibiotics when VAP is suspected.

Study of the clinical relevance of Helicobacter pylori virulence genes to gastric diseases among Egyptian patients.

BACKGROUND AND STUDY AIMS Helicobacter pylori infection is common in Egypt. It has been associated with gastritis, ulcers and it is a risk factor for gastric cancer. We aimed to study the correlation between the presence of H. pylori virulence factors and the histopathological and endoscopic findings in gastric biopsies. PATIENTS AND METHODS Gastric biopsies from thirty seven patients scheduled for diagnostic endoscopy in Cairo University hospital were included in the study. All gastric biopsies were subjected to histopathological examination and PCR assay for detection of 16S rRNA gene to diagnose H. pylori infection, detection of H. pylori virulence factors by PCR for cagA and vacA genotypes and serological analysis of H. pylori (cagA, vacA, P25, and P19) IgG antibodies by immunoblot assay were done. RESULTS H. pylori infection was detected in 23 (62.2%) cases by histopathology while 28/37 (75.7%) were positive for H. pylori 16S rRNA gene by PCR. By PCR seventeen samples out of 37 (45.9%) were positive for cagA gene and five (13.5%) for cag empty site gene. CONCLUSION The most common vacA genotype identified was vacA s2m2 genotype in 10 (27.02%). No statistical correlation was found between IgG antibodies against different antigens of H. pylori virulence factors (cagA, vacA, p25, and p19) and the degree of gastritis except for IgG antibodies against the UreA antigen.

Rapid identification of nosocomial Acinetobacter baumannii isolated from a surgical intensive care unit in Egypt.

BACKGROUND The rapid and accurate identification of nosocomial clinical isolates is the first essential step in investigating nosocomial outbreaks. We aimed to evaluate the performance of MDR-CHROMagar Acinetobacter versus matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) in rapid detection of nosocomial Acinetobacter baumannii isolated from patients admitted to the surgical intensive care unit (SICU) of Kasr Alainy-Cairo University. METHODS Over a period of 9 months from January 2014 until September 2014, 234 samples were collected. All samples were directly cultured on MDR-CHROMagar Acinetobacter media. MALDI-TOF MS was used to identify all non-lactose fermenting colonies on conventional media. Confirmation of species identification was done by detecting the blaOXA-51 like gene by PCR. RESULTS Statistical evaluation of MDR-CHROMagar Acinetobacter against blaOXA-51 like PCR as the reference method for identification of A baumannii showed a sensitivity of 100% (95% confidence interval [CI]: 93.36% to 100%), specificity 98.8% (95% confidence interval [CI]: 96.04% to 99.68%), positive predictive value 96.4% (95%CI: 86.61% to 99.37%), negative predictive value 100% (95% CI: 97.36% to 100%). The statistical evaluation of MALDI-TOF against blaOXA-51 PCR was 100% concordance. CONCLUSION MALDI-TOF MS was more specific than CHROMagar in identifying Acinetobacter spp and allowed further identification of non-A Baumannii species such as A hemolyticus and A nosocomialis, which are less common Acinetobacter spp involved in hospital-acquired infections.

Ventilator associated pneumonia caused by extensive-drug resistant Acinetobacter species: Colistin is the remaining choice

Abstract Introduction Ventilator-associated pneumonia [VAP] is associated with increased morbidity and mortality especially when caused by extensive drug resistant [XDR] pathogens. Till now, little is known regarding the exact pathogenesis of XDR Acinetobacter baumannii [XDR-AB] infection. The aim of the present study was to identify prevalence and risk factors for VAP caused by XDR-AB in our intensive care unit, and to test the susceptibility pattern of tigecycline, carbapenems, and Colistin among the isolates. Methods A prospective cohort study was conducted to enroll patients who developed VAP over 18-month period. All possible risk factors were documented as well as patient outcome. Susceptibility testing for the isolates was performed using inhibitory concentrations [MICs] determined by Epsilometer tests (E-tests) to Carbapenems, Tigecycline, and Colistin. Results Among 544 consecutive patients admitted to our ICU during 18 months, Forty-seven patients developed VAP. The prevalence of XDR-AB was 63.8% (30 patients). No specific factor was associated with increase of the risk of acquisition of AB-VAP in our cohort either by univariate or by multivariate analysis. Carbapenems showed poor activity against all isolates [MIC range 10–128 mg/L]. Tigecycline showed good activity against only 15 isolates [MIC range 0.25–2 mg/L]. Colistin demonstrated potent in vitro activity against all isolates of AB [MIC range 0.016–1 mg/L]. Conclusions XDR AB-VAP is endemic in our ICU without a definite factor associated with increased risk of infection. Given that almost half of the strains are also resistant to tigecycline, colistin appears to be an appropriate first-line antimicrobial drug in critically ill patients developing VAP based on invitro results.

Role of insertion sequence Aba-1 and AdeS in reduced tigecycline susceptibility in MDR-Acinetobacter baumannii clinical isolates from Cairo, Egypt

Infections caused by multidrug resistant (MDR) Acinetobacter baumannii (A. baumannii) especially in intensive care units have limited therapeutic options. Overexpression of the adeABC efflux pump may be caused either by the ISAba-1 insertion or by specific point mutations in adeR and adeS, therefore, plays a major role in conferring MDR-A. baumannii. We aimed in our study to monitor the tigecycline (TGC) susceptibility and to study the role of ISAba-1 and the adeS regulator within the AdeABC efflux pump among MDR-A. baumannii clinical isolates. MDR-A. baumannii (63) isolated from ICU patients were identified by detection of OXA-51-like gene. TGC MIC was determined by E-test and broth microdilution. PCR analysis of adeR, adeS, adeB and ISAba1 genes were done with further sequencing of adeS gene. Reduced susceptibility to TGC (MIC: 3–4 mg/L) was noticed in 6/63 (9.5%) MDR-A. baumannii isolates, ISAba-1 was detected in three isolates that two of which showed amino acid substitutions in the adeS operon. We concluded that the amino acids mutations in the adeS gene in presence of insertion ISAba-1 may play a role in conferring reduced TGC susceptibility of MDR-A. baumannii.

Reduced susceptibility of Enterococcus spp. isolates from Cairo University Hospital to tigecycline: Highlight on the influence of proton pump inhibitors

OBJECTIVES The incidence of reduced susceptibility to tigecycline (TIG) is increasing. This study aimed to analyse the in vitro activity of TIG against Enterococcus spp. isolates recovered from hospitalised patients and to evaluate the effect of omeprazole on the in vitro antimicrobial activity of TIG against several enterococcal species. METHODS A total of 67 Enterococcus clinical isolates were identified by MALDI-TOF/MS and multiplex PCR. Minimum inhibitory concentrations (MICs) of TIG alone and in combination with omeprazole (10, 30 and 60mg/L) were determined by broth microdilution. Antibiotic susceptibility to other antibiotics was determined by disk diffusion. The presence of van, tet(X) and tet(X1) genes was tested by multiplex PCR. RESULTS Of the 67 Enterococcus isolates, 2 (3.0%) were resistant to TIG and 13 (19.4%) were intermediate-resistant according to EUCAST. The frequencies of resistance to norfloxacin (80.6%), doxycycline (80.6%), levofloxacin (74.6%) and ciprofloxacin (71.6%) were highest, whilst that of vancomycin (25.4%) was lowest. The vanA gene was detected in 11 Enterococcus isolates (8 Enterococcus faecalis, 3 Enterococcus faecium), vanB in 3 Enterococcus isolates (2 E. faecium, 1 E. faecalis) and vanC-2/3 in 3 Enterococcus casseliflavus. Nine isolates (13.4%) were positive for tet(X1). TIG resistance occurred both in patients receiving or not TIG and/or omeprazole. Omeprazole increased TIG MICs by 4-128-fold. CONCLUSIONS The possibility of selection of TIG-non-susceptible Enterococcus in the gut may occur with long-term use of omeprazole. Omeprazole influenced TIG activity in a concentration-dependent manner. To our knowledge; this is the first report of TIG-non-susceptible Enterococcus spp. in Egypt.

Rapid screening for group B Streptococcus in near-term pregnant women by Granada™ biphasic broth

Abstract Background: Prenatal screening for group B Streptococcus (GBS) colonization can reduce the incidence of neonatal GBS infections. We aimed to improve the screening-based approach of GBS in a limited resources antenatal care clinic by using Strep B Granada™ Biphasic Broth. Methods: This study included 80 pregnant women between 35 and 37 weeks of gestation, who attended the antenatal care clinic of Kasr El-Aini University Hospital from November 2013 to January 2014. Two high vaginal swabs were collected, then transported using Amies transport medium. One vaginal swab was processed by conventional culture-based methods on 5% sheep blood agar plates. The other swab was immersed in 3 mL selective enrichment broth (Granada™ Biphasic Broth bioMérieux). Results: Among 80 pregnant women, GBS was detected in 9 (11.25%) of the studied cases within 18–24 hours. Detection of orange-red colonies in GBS Granada broth was 100% specific for the presence of beta-hemolytic group B streptococci. Conclusion: Using Granada biphasic broth media was easy, affordable and shortened the turnaround time needed for the detection of GBS by conventional culture methods. Routine screening of pregnant women for vaginal GBS colonization by Granada™ Biphasic broth would allow properly timed prenatal antimicrobial prophylaxis to prevent possible neonatal infections.

Emerging New Delhi metallo-β-lactamase-1-type-producing Gram-negative bacteria isolated from Cairo University Pediatric Hospital, Cairo, Egypt.

New Delhi metallo-β-lactamase (NDM) compromises the efficacy of almost all β-lactam antibiotics, including carbapenems. This study aimed to screen for the blaNDM-1-type gene and NDM-1-type carbapenemase production among Gram-negative bacteria in Cairo University Pediatric Hospital (Cairo, Egypt). Among 382 Gram-negative clinical isolates collected over the period October 2013 to May 2014, 100 clinical isolates showing reduced carbapenem (imipenem and meropenem) susceptibility were included in this study. Initial phenotypic screening for NDM enzyme production was performed by Etest for metallo-β-lactamases (EMBL). Genotypic detection of the blaNDM-1-type gene was done by TaqMan real-time PCR. Metallo-β-lactamase production was detected in 23% of the isolates by EMBL, whereas 24% of the isolates were found to be positive for the blaNDM-1-type gene by real-time PCR. The EMBL sensitivity was 79.2%, specificity was 94.7%, positive predictive value was 82.6%, negative predictive value was 93.5% and overall accuracy was 91.0%. Seventeen (70.8%) of blaNDM-1-type-positive cases were hospital-acquired in origin, whilst 7 cases (29.2%) were community-acquired. Eleven isolates (45.8%) harbouring blaNDM-1-type were found in critical care units. In conclusion, the high prevalence of blaNDM-1-type carbapenemase gene among Gram-negative bacteria, with its great potential for spread in intensive care units, warrants the attention of a nationwide surveillance programme to contain its spread.