Guillermo Pimentel

Publications (32) View all

• Article: In vitro antibiotic susceptibility testing of Brucella isolates from Egypt between 1999 and 2007 and evidence of probable rifampin resistance.

  Mohamed Abdel-Maksoud, Brent House, Momtaz Wasfy, Bassem Abdel-Rahman, Guillermo Pimentel, Gehan Roushdy, Erica Dueger
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  ABSTRACT: Brucellosis poses a significant public health problem in Mediterranean countries, including Egypt. Treatment of this disease is often empirical due to limited information on the antibiotic susceptibility profiles of Brucella spp. in this region of the world. The aim of this study was to determine the antibiotic susceptibility profiles of Brucella blood isolates in Egypt, a country endemic for brucellosis. Brucella spp. isolates were identified from the blood cultures of acute febrile illness (AFI) patients presenting to a network of infectious disease hospitals from 1999-2007. Minimum inhibitory concentrations were determined for tetracycline, gentamicin, doxycycline, trimethoprim-sulfamethoxazole, streptomycin, ceftriaxone, ciprofloxacin and rifampin using the E-test. Interpretations were made according to Clinical and Laboratory Standards Institute (CLSI) guidelines. A total of 355 Brucella spp. isolates were analyzed. All were susceptible to tetracycline, doxycycline, trimethoprim-sulfamethoxazole, streptomycin and ciprofloxacin; probable resistance to rifampin and ceftriaxone was observed among 277 (64%) and 7 (2%) of the isolates, respectively. Percentages of isolates showing probable resistance to rifampin were significantly lower before 2001 than in the following years (7% vs. >81%, p < 0.01). Despite the high burden of brucellosis in Egypt and frequent empirical treatment, isolates have remained susceptible to the majority of tested antibiotics. However, this is the first report of high rates of probable resistance to rifampin among Brucella isolates from Egypt. Patients should be closely monitored while following standard treatment regimens. Continued surveillance, drug susceptibility studies and updated CLSI interpretive criteria are needed to monitor and update antibiotic prescribing policies for brucellosis.
  Annals of Clinical Microbiology and Antimicrobials 08/2012; 11:24. · 2.64 Impact Factor
• Article: Hotel clinic-based diarrheal and respiratory disease surveillance in U.S. service members participating in Operation Bright Star in Egypt, 2009.

  Peter J Sebeny, Isabelle Nakhla, Manal Moustafa, Jody A Bruton, Joanne Cline, Douglas Hawk, Hanan El-Mohammady, Rania A Nada, Salwa F Ahmed, Guillermo Pimentel, Sylvia Y N Young
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  ABSTRACT: We conducted clinic-based, influenza-like illness and diarrheal disease surveillance among U.S. service members participating in Operation Bright Star 2009. Epidemiologic data and samples were collected. Nasopharyngeal swab specimens were tested for viruses, and feces was tested for microbiologic, immunologic, and molecular diagnostics. A survey was used to collect self-reported data. From 1,529 surveys, 41% reported diarrheal disease and 25% reported respiratory illness (incidence rate = 62 of 100 versus 37 of 100 person-months; incidence rate ratio = 1.7, 95% confidence interval = 1.5-1.9). Enterotoxigenic Escherichia coli was identified in 74% (69 of 93) of fecal samples. In the influenza-like illness case series, 17% (9 of 52) were positive for influenza A; all were positive for pandemic (pH1N1) 2009 virus. Rates of decreased work performance reported by patients with diarrhea and influenza-like illness were similar (46% versus 48%; P = 0.8). Diarrheal diseases and respiratory illness remain common among deployed military personnel, with important operational impact. Despite an ongoing influenza pandemic, diarrheal disease incidence was higher than that of respiratory illness.
  The American journal of tropical medicine and hygiene 08/2012; 87(2):312-8. · 2.59 Impact Factor
• Article: Genetic diversity and antibiotic resistance in Shigella dysenteriae and Shigella boydii strains isolated from children aged <5 years in Egypt.

  A M El-Gendy, A Mansour, M A Weiner, G Pimentel, A W Armstrong, S Y N Young, N Elsayed, J D Klena
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  ABSTRACT: Diversity within Shigella dysenteriae (n=40) and Shigella boydii (n=30) isolates from children living in Egypt aged <5 years was investigated. Shigella-associated diarrhoea occurred mainly in summer months and in children aged <3 years, it commonly presented with vomiting and fever. Serotypes 7 (30%), 2 (28%), and 3 (23%) accounted for most of S. dysenteriae isolates; 50% of S. boydii isolates were serotype 2. S. dysenteriae and S. boydii isolates were often resistant to ampicillin, chloramphenicol and tetracycline (42%, 17%, respectively), although resistance varied among serotypes. Pulsed-field gel electrophoresis separated the isolates into distinct clusters correlating with species and serotype. Genetic differences in trimethoprim/sulfamethoxazole and β-lactam-encoding resistance genes were also evident. S. dysenteriae and S. boydii are genetically diverse pathogens in Egypt; the high level of multidrug resistance associated with both pathogens and resistance to the most available inexpensive antibiotics underlines the importance of continuing surveillance.
  Epidemiology and Infection 04/2011; 140(2):299-310. · 2.84 Impact Factor
• Article: Laboratory-based surveillance for patients with acute meningitis in Sudan, 2004-2005.

  S Afifi, M S Karsany, M Wasfy, G Pimentel, A Marfin, R Hajjeh
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  ABSTRACT: To determine the burden of bacterial meningitis and characterize its epidemiology, a laboratory-based surveillance was established in five hospitals in Sudan. Hospital personnel were trained in basic surveillance and bacteriology techniques. Positive cerebrospinal fluid (CSF) cultures were confirmed at Sudan National Laboratories and U.S. Naval Medical Research Unit No. 3. Additionally, 126 frozen CSF samples from culture-negative meningitis cases were tested by polymerase chain reaction (PCR). Of 1,830 suspected meningitis cases enrolled, 75% were less than 5 years old and 63% were males. Of these, 149 (8%) were culture-confirmed, including 121 (81%) Neisseria meningitidis; 18 (12%) Streptococcus pneumoniae, and 10 (7%) Haemophilus influenzae. Of 440 turbid specimens, 132 (30%) were culture-positive. Of the 126 samples from culture-negative meningitis cases that were tested, only 18 (14%) were classified as turbid on gross examination, yet 63 (50%) were positive by PCR. This study suggests that PCR may be useful to more accurately define the burden of disease in epidemic setting. Maintaining laboratory-based surveillance allows evidence-based decision-making and helps monitor the impact of new vaccines introduction.
  European Journal of Clinical Microbiology 12/2008; 28(5):429-35. · 2.86 Impact Factor
• Article: Surveillance of catheter-associated urinary tract infection in 4 intensive care units at Alexandria university hospitals in Egypt.

  Maha Talaat, Soad Hafez, Tamer Saied, Reham Elfeky, Waleed El-Shoubary, Guillermo Pimentel
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  ABSTRACT: We sought to measure the incidence rate of catheter-associated urinary tract infections (CAUTIs), identify risk factors associated with acquiring the infections; and identify the etiologic and antibiotic resistant patterns associated with CAUTIs in the intensive care units (ICUs) of a large University Hospital in Alexandria, Egypt. Prospective active surveillance of CAUTIs was conducted in 4 ICUs during a 13-month period from January 1, 2007 through January 31, 2008 in Alexandria University Hospital using the standard Centers for Disease Control National Nosocomial Infection Surveillance (NNIS) case definitions. Rates were expressed as the number of infections per 1000 catheter days. During the study period, 757 patients were monitored after ICU admission, with either existing indwelling urinary catheters (239), or got catheters inserted after ICU admission (518), for a total duration of 16301 patient days, and 10260 patient catheter days. A total of 161 episodes of infection were diagnosed, for an overall rate of 15.7 CAUTIs per 1000 catheter days. Important risk factors associated with acquiring CAUTI were female gender (Relative risk (RR), 1.7; 95% confidence interval (CI); 1.7-4.3), and previous catheterization within the same hospital admission (RR, 1.6; 95% CI; 1.3-1.96). Patients admitted to the chest unit, patients =40 years, patients with prolonged duration of catheterization, prolonged hospital and ICU stay had a significantly higher risk of acquiring CAUTIs. Out of 195 patients who had their urine cultured, 188 pathogens were identified for 161 infected patients; 96 (51%) were Candida, 63 (33.5%) gram negatives, 29 (15.4%) gram positives. The prevalence of ESBL producers among K. pneumoniae and E. coli isolates was 56% (14/25) and 78.6% (11/14), respectively. Despite infection control policies and procedures, CAUTI rates remain a significant problem in Alexandria University hospital. Using the identified risk factors, tailored intervention strategies are now being implemented to reduce the rates of CAUTIs in these 4 ICUs.
  American journal of infection control 10/2009; 38(3):222-8. · 3.01 Impact Factor