Extended-spectrum ß-lactamase-producing Klebsiella pneumoniae in the neonatal intensive care unit: does vancomycin play a role?

BACKGROUND: Extended-spectrum ß-lactamase (ESBL)-producing Klebsiella species cause worldwide problems in neonatal intensive care units (NICUs). This study aimed to determine possible risk factors for infection or colonization with ESBL-producing Klebsiella pneumoniae (ESBLKp) during an outbreak in the NICU. METHODS: A retrospective cohort study was conducted among neonates admitted to the NICU of a teaching hospital in Riyadh, Saudi Arabia, during an outbreak of ESBLKp from April to July 2008. The incidence density ratio was calculated to determine possible predictors of ESBLKp colonization or infection. RESULTS: During 2,265 person-days of follow-up of 118 neonates, 4 became infected, and 8 were colonized with ESBLKp. Univariate analyzes revealed that, among 14 neonates who were treated with vancomycin, 9 (64.3%) developed infection or colonization with ESBLKp, whereas, among 104 neonates who were not treated with vancomycin, 3 (2.9%) were affected, with an incidence density ratio of 4.22 (95% confidence interval: 1.47-5.15). Parenteral feeding and mechanical ventilation were found to be marginally significant risk factors. CONCLUSION: Treatment with vancomycin appears to be a risk factor for infection or colonization with ESBLKp in the NICU setting.

Brucella spp isolated from respiratory sample and grown in Mycobacterium growth indicator tube (MGIT).

Brucellosis remains endemic in many countries including Saudi Arabia. The disinfection of objects and surfaces contaminated with Brucella spp is not difficult, but we encountered a situation in which the organism survived the decontamination and liquefaction procedure adopted for AFB culture. A sputum specimen from a patient was sent for TB culture and the BACTEC MGIT 960 system isolated an organism identified as Brucella spp. The blood cultures and the serological testing had confirmed this case to be brucellosis. Isolation of Brucella spp from sputum samples is rare; this case appears to be the first of its kind. As the clinical presentation of TB may mimic brucellosis and vice versa, we recommend that handling specimens from all cases of undiagnosed PUO should be done with care because of the possibility that it may contain either of these organisms.

Antimicrobial susceptibility patterns of multidrug-resistant Pseudomonas aeruginosa and Acinetobacter baumannii against carbapenems, colistin, and tigecycline.

OBJECTIVE: To examine susceptibility of Pseudomonas aeruginosa (P. aeruginosa) and Acinetobacter baumannii (A. baumannii ) against carbapenems along with colistin and tigecycline as alternative therapeutic options. METHODS: A total of 117 strains of multidrug-resistant (MDR) non-fermenting Gram negative bacteria isolated from non-duplicate samples were collected consecutively. We included one sample from each patient (84 isolates of A. baumannii and 33 isolates of P. aeruginosa isolated from patients seen at King Khalid University Hospital, Riyadh, Saudi Arabia, from June to December 2010). Isolates were identified by the MicroScan WalkAway 96 Plus system. The minimum inhibitory concentrations (MICs) were determined by E-test following the Clinical and Laboratory Standards Institute breakpoint recommendations. RESULTS: Most A. baumannii strains were resistant to imipenem (90.5%), meropenem (90.5%), and doripenem (77.4%). Whereas, a higher percentage of P. aeruginosa was resistant to imipenem (90.9%), and meropenem (81.8%), only 39.4% were resistant to doripenem. Colistin had excellent activity against both A. baumannii (100%) and P. aeruginosa (93.9%), while 89.3% of A. baumannii strains were susceptible to tigecycline. CONCLUSION: Among the carbapenems, doripenem was found to be the most potent antimicrobial agent against P. aeruginosa, whereas colistin proved to be an effective alternative antimicrobial agent for treatment of A. baumannii or P. aeruginosa. Tigecycline remains the best therapeutic option for MDR A. baumannii.

CD4+ T-lymphopenia in HIV negative tuberculous patients at King Khalid University Hospital in Riyadh, Saudi Arabia.

Tuberculosis (Tb) is a chronic infectious disease in which the cellular immunity (specifically CD4+ and CD8 lymphocytes) provides the most important defense in controlling infection. CD4 lymphopenia is a well-defined risk factor for the development of active tuberculosis in patients infected with Human Immunodeficiency Virus. In HIV - negative patients, CD4 and CD8 cell count suppression has been associated with Tb infection. Our study was designed to determine the baseline and post-treatment values of CD4 and CD8 in HIV negative patients diagnosed with active Tb in Saudi Arabian patients. We recruited twenty-eight, non-HIV patients with tuberculosis for the study group comprising 16 males and 12 females with either disseminated or localized active Tb infection. Two control groups were selected one of twenty-one matched healthy controls and the second of forty-two subjects from pool of controls of an ongoing study in same population for normal CD4 and CD8 counts. The baseline pre-treatment CD4 and CD8 counts in the study group were significantly lower than either control group. Specifically the mean ± SD of CD4 counts were 556.79 ± 298.81 in the study group vs 1,132.38 ± 259.90 in control group 1 and 1,424.38 ± 870.98 in control group 2 (p 0.000). Likewise the CD8 counts in the study group were 1,136.00 ± 512.06 vs. 1,461.90 ± 367.02 in control group 1 and 1,495.90 ± 565.32 in control group 2 (p 0.000) respectively. After treatment of tuberculosis, the study patients experienced a significant increase in their mean ± SD CD4 and CD8 cell counts, from 556.79 ± 297.81 to 954.29 ± 210.90 for CD4 cells (p 0.005) and 1136.00 ± 512.06 to 1,316.54 ± 286.17 for CD8 cells (p 0.002). Analysis of study patients with disseminated disease found significantly lower CD4 cells (but not lower CD8 cells) compared to study patients with localized disease, both at baseline and after treatment. The mean ± SD baseline CD4 cells were 247.60 ± 187.80 with disseminated vs 728.56 ± 186.32 for localized disease (p = 0.000) which rose to 842.30 ± 93.55 vs 1016.50 ± 233.51 (p = 0.033) respectively. We conclude that tuberculosis may be associated with CD4 and CD8 lymphopenia even in patients without human immunodeficiency virus infection, there was the tendency of recovery towards normality especially of the CD4 and CD8 counts after treatment, and that disseminated disease is associated specifically with profound CD4 lymphopenia.

Mycobacterium chelonae complex bacteremia from a post-renal transplant patient: case report and literature review.

In this report we present a case of a young lady with abdominal abscesses and septicemia caused by Mycobacterium chelonae complex. Identification of the organism and initiation of the appropriate antimicrobial therapy was delayed, resulting in significant morbidity and multiple hospital admissions. Gram staining of these organisms from blood culture can be easily overlooked or confused with either debris or diptheroids. We concluded that detection of Gram-positive rod colonies should prompt an acid-fast stain to distinguish diphtheroids from rapidly growing mycobacteria in immunosuppressed patients.

A review of gastrointestinal manifestations of Brucellosis.

Brucellosis is hyperendemic in the Kingdom of Saudi Arabia (KSA) with more than 8,000 cases reported each year to the public health authorities. The disease can affect almost any organ system in the body including the gastrointestinal system. In some instances, gastrointestinal manifestations may be the only presenting features of the disease. These range from milder complaints like diarrhea, vomiting to more serious complications like involvement of the liver, the spleen and the gallbladder to rarely life-threatening complications like colitis, pancreatitis, peritonitis and intestinal obstruction. Recognition of this type of presentation of brucellosis is important because early diagnosis and treatment usually result in complete recovery without complications.