Antibiotic susceptibility and resistance among bacterial enteropathogens isolated from international travelers to Mexico, Guatemala, and India, 2006--2008

The incidence rates of travelers' diarrhea (TD) have remained unchanged for the last fifty years. More recently, there have been increasing recommendations for self-initiated therapy and even prophylactic therapy for TD. There is no recent data on the in vitro activities of commonly used antibiotics for TD therapy and whether there have been any changes in susceptibilities over the last ten years. 456 enteropathogens were isolated from adult travelers to Mexico, India, and Guatemala between the years 2006 to 2008. MICs were determined for 10 different antimicrobials by the agar dilution method. Traditional antibiotics such as ampicillin, trimethoprim/sulfamethoxazole, and doxycycline continue to show high levels of resistance. Current first line antibiotic agents including fluoroquinolones and azithromycin had significantly higher MICs when compared to 10 years ago and MIC90 levels were beyond the CSLI cutoffs for resistance. There were significant geographical differences in resistance patterns when comparing Central America with India. Entertoxigenic Escherichia coli (ETEC) isolates were more resistant to ciprofloxacin (p=0.023), and levofloxacin (p=0.0078) in India; whereas, enteroaggregative Escherichia coli (EAEC) isolates from Central America showed more resistance. When compared to MICs of isolates 10 years prior, there was a four to ten-fold increase in MIC90s for ceftriaxone, ciprofloxacin, levofloxacin and azithromycin for both ETEC and EAEC. There were no significant changes in rifaximin MICs over the last ten years, which makes it a promising agent for TD. Rising MICs over time implicate the need for continuous surveillance of susceptibility patterns worldwide and for geography specific recommendations in TD therapy.^

Fecal coliform contamination in child day care environments in Houston, Texas

Outbreaks of diarrhea are common among children in day care centers (DCC). Enteropathogens associated with these outbreaks are spread by the fecal-oral route through contaminated hands or environmental objects. This prospective study was undertaken to determine the prevalence of fecal coliform (FC) contamination in the DCC environment. Ten rooms in 6 DCC housing 121 children $<$2 years of age were studied for 13 weeks. Inanimate objects (1275), toy balls (724), and hands (954) were cultured 1-3 times per week. FC contamination was common during each week of study and was significantly (p $<$ 0.05) greater for objects, toy balls, and hands of children in toddler compared to infant rooms. In 5 rooms in which clothes were worn over diapers, there was a significantly lower prevalence of FC of toy balls (p $<$ 0.005), inanimate objects (p $<$ 0.05), and hands of children (p $<$ 0.001) and caregivers (p $<$ 0.05) when compared to rooms in which overclothes were not worn. Occurrence of diarrhea was significantly associated with increased contamination of caregivers' and children's hands. Using plasmid analysis of trimethoprim (TMP)-resistant Escherichia coli, stool and environmental isolates from individual DCC rooms had the same plasmid patterns, which were unique to each center. In summary, FC of environmental isolates and hands of children and caregivers in DCC is common; toy balls can serve as sentinels of contamination; FC can be significantly decreased by use of clothes worn over diapers; and plasmid analysis of E. coli strains showed the same patterns from stool and environmental isolates. ^

Retrospective analysis of Methicillin-Resistant Staphylococcus Aureus (MRSA) skin and Soft-Tissue Infections (SSTI) in a university hospital emergency department (ED)

Study Objective: Identify the most frequent risk factors of Community Acquired-MRSA (CA-MRSA) Skin and Soft-tissue Infections (SSTIs) using a case series of patients and characterize them by age, race/ethnicity, gender, abscess location, druguse and intravenous drug-user (IVDU), underlying medical conditions, homelessness, treatment resistance, sepsis, those whose last healthcare visit was within the last 12 months, and describe the susceptibility pattern from this central Texas population that have come into the University Medical Center Brackenridge (UMCB) Emergency Department (ED). ^ Methods: This study was a retrospective case-series medical record review involving a convenience sample of patients in 2007 from an urban public hospital's ED in Texas that had a SSTI that tested positive for MRSA. All positive MRSA cultures underwent susceptibility testing to determine antibiotic resistance. The demographic and clinical variables that were independently associated with MRSA were determined by univariate and multivariate analysis using logistic regression to calculate odds ratios (OR), 95% confidence intervals, and significance (p≤ 0.05). ^ Results: In 2007, there were 857 positive MRSA cultures. The demographics were: males 60% and females 40%, with the average age of 36.2 (std. dev. =13) the study population consisted of non-Hispanic white (42%), Hispanics (38%), and non-Hispanic black (18.8%). Possible risk factors addressed included using recreational drugs (not including IVDU) (27%) homelessness (13%), diabetes status (12.6%) or having an infectious disease, and IVDU (10%). The most frequent abscess location was the leg (26.6%), followed by the arm and torso (both 13.7%). Eighty-three percent of patients had one prominent susceptibility pattern that had a susceptibility rate for the following antibiotics: trimethoprim/sulfamethoxazole (TMP-SMX) and vancomycin had 100%, gentamicin 99%, clindamycin 96%, tetracycline 96%, and erythromycin 56%. ^ Conclusion: The ED is becoming an important area for disease transmission between the sterile hospital environment and the outside environment. As always, it is important to further research in the ED in an effort to better understand MRSA transmission and antibiotic resistance, as well as to keep surveillance for the introduction of new opportunistic pathogens into the population. ^