MRSA Found in U.S. Wastewater Treatment Plants

 MRSA is a type of staph bacteria that is resistant to certain antibiotics called beta-lactams (Centers for Disease Control and Prevention [CDC], 2012).  Some beta-lactam antibiotics: Dicloxacillin, Methicillin, Oxacillin and Temocillin.  Typically people who are infected are hospital patients and those who are infected can shed MRSA from their skin, nose and feces. Methicillin-resistant Staphylococcus aureus (MRSA)

 There has been a rise in CA-MRSA cases since the 1990s  Researchers at the University of Maryland School of Public Health (UMD) wanted to find out how healthy people were coming into contact with this microorganism.  The UMD research team tested the water from four U.S. WWTPs.  These plants were chosen because they used the treated effluent water as reclaimed wastewater for spray irrigation activities. The rise of community-acquired MRSA cases (CA-MRSA)

 MRSA along with methicillin-susceptible Stapylococcus aureus (MSSA) were found in all four of the WWTPs.  Only 1 in 4 of the WWTPs had bacteria present in the effluent. The WWTP did not always use chlorination in their treatment process.  MRSA was found in 83% of the influent  93% of the MRSA strains and 55% of the MSSA strains isolated were resistant to two or more classes of antibiotics Results

 At two of the WWTPs the MRSA strains found had more resistance to antibiotics.  The chlorination step is what wiped out all MRSA from the effluent.  Wastewater treatment does reduce the amount of MRSA and MSSA in the effluent. However, it is causing an increase in antibiotic resistance.  The use of reclaimed wastewater becomes a public safe issue especially for the workers at the WWTPs and anyone who comes in contact with the reclaimed wastewater. Results cont.