MRSA break­through may spell the end for drug-re­sis­tant bac­te­ria

China Daily (Canada) - - CHINA -

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The per­cent­age should have been lower, given that only 10 per­cent of flu symp­toms are caused by bac­te­rial in­fec­tion and an­tibi­otics act against bac­te­ria but not viruses. There­fore, it seems likely that a large num­ber were pre­scribed to treat vi­ral in­fec­tions, such as com­mon colds, sore throats and flu.

On the pos­i­tive side, an­tibi­otics have been pre­scribed as pre­ven­tive mea­sures. Pa­tients with vi­ral in­fec­tions have weak­ened im­mune sys­tems, which makes them vul­ner­a­ble to sec­ondary bac­te­rial in­fec­tions. An­tibi­otics may help to pre­vent that, Kao said.

Mar­gret Ip, hon­orary con­sul­tant at the De­part­ment of Mi­cro­bi­ol­ogy at Prince of Wales Hospi­tal, said Hong Kong’s pub­lic hos­pi­tals im­posed vig­or­ous reg­u­la­tion of an­tibi­otic pre­scrip­tion after SARS, so an­tibi­otic mis­use may be rife in the pri­vate health sec­tor.

As pathogens keep evolv­ing and be­come more com­plex, the symp­toms of bac­te­rial and vi­ral in­fec­tions are now more in­dis­tinct, Ip said: “It’s pos­si­ble that doc­tors in pri­vate clin­ics, with­out suf­fi­cient and up­dated pa­tient data to re­fer to, mis­tak­enly pre­scribe an­tibi­otics for the wrong ail­ments.”

She sug­gested es­tab­lish­ing a plat­form to share in­for­ma­tion be­tween hos­pi­tals and clin­ics, so fam­ily doc­tors can keep track of changes in con­ta­gious dis­eases and the best reme­dies to em­ploy.

Hong Kong’s pri­vate prac­ti­tion­ers can log an­tibi­otic pre­scrip­tions on an elec­tronic health record sys­tem, but it’s vol­un­tary.

The city is us­ing the plat­form to mon­i­tor an­tibi­otic use in pri­vate clin­ics, but many peo­ple have ques­tioned its ef­fec­tive­ness be­cause physi­cians rarely re­port ex­ces­sive pre­scrip­tion if it is not manda­tory to do so. an­tibi­otics from a physi­cian.

Glob­ally, sur­veys in­di­cate that an­tibi­otic con­sump­tion in high-in­come economies was rel­a­tively con­stant from 2000 to 2015, and the rise was pre­dom­i­nantly driven by low- and­lower-mid­dle in­come economies, such as In­dia, China and Pak­istan.

More­over, hu­mans are not the ma­jor con­sumers. In­stead, an­i­mals ac­count for large amounts of an­tibi­otics that are used to treat or pre­vent dis­ease, or fat­ten them for mar­ket.

In 2013, global use of an­tibi­otics in food an­i­mals was around 131,100 met­ric tons, and is pro­jected to rise to around 200,000 tons by 2030.

“It would be best to ban all an­tibi­otic ap­pli­ca­tions on farms. How­ever, that would lead to ris­ing food prices and make life tougher for peo­ple on lower in­comes,” Kao said. “Most poul­try in Hong Kong is im­ported, and in light of that it’s hard to im­pose con­trols.”

Last year, the Min­istry of Agri­cul­ture on the Chi­nese main­land is­sued mea­sures to re­duce an­tibi­otics in poul­try and live­stock, and au­thor­i­ties in­tend to abol­ish more than 100 high-risk drugs cur­rently used on an­i­mals. By 2020, more than 97 per­cent of poul­try, live­stock and aquatic prod­ucts on the main­land are likely to qual­ify as se­cure food sources, with an­tibi­otic residues well within safety stan­dards.

In Novem­ber, the Hong Kong govern­ment pub­lished a five-year plan to com­bat drug re­sis­tance.

By 2022, it aims to bar breed­ers from us­ing an­tibi­otics on live­stock un­less the drugs are pre­scribed by vets. In ad­di­tion, the Agri­cul­ture, Fish­eries and Con­ser­va­tion De­part­ment will stop is­su­ing an­tibi­otic per­mits that al­low farm­ers to pur­chase and possess an­tibi­otics used on farm an­i­mals.

Re­cent lab tests on mice show that those in­fected with CA-MRSA had a 40 per­cent sur­vival rate after seven to 10 days. A sep­a­rate group, in­jected with non-an­tibi­otic M-21, Kao’s break­through, all sur­vived.

The find­ings were pub­lished in July in the jour­nal Pro­ceed­ings of the Na­tional Academy of Sciences of the United States of Amer­ica.

Ip, of Prince of Wales Hospi­tal, sup­ports Kao’s ap­proach. “In light of to­day’s sweep­ing an­timi­cro­bial re­sis­tance aris­ing from an­tibi­otics, the non-an­tibi­otic ap­proach is the way to rein in the prob­lem,” she said. Ip is ex­plor­ing nat­u­ral com­pounds in herbs such as skull­cap root and Chi­nese goldthread to see if they can pro­duce drugs to beat su­per­bugs.

How­ever, Qian Pei-yuan, chair pro­fes­sor of the Divi­sion of Life Science at the Hong Kong Univer­sity of Science and Tech­nol­ogy, said MRSA may still ac­quire the abil­ity to fend off M-21, as it did an­tibi­otics.

This year, he iden­ti­fied an en­zyme called D-stere­ospe­cific re­sis­tance pep­ti­dases, seen in many bac­te­ria, which is a key fac­tor in MRSA’s abil­ity to break down pep­tide an­tibi­otics, in­clud­ing van­comycin.

Kao an­tic­i­pates that M-21 will be man­u­fac­tured as a med­i­ca­tion and un­dergo clin­i­cal tri­als after five years, be­fore be­ing tested on hu­man pa­tients. If it’s proven safe, he ex­pects the first batch of M-21 to be used to treat pa­tients with CA-MRSA.

The M-21 break­through, a quan­tum leap in the fight against an­timi­cro­bial pathogens, earned Kao’s team first prize at the In­no­va­tion Academy Awards at the In­ter­na­tional Con­sor­tium for Preven­tion & In­fec­tion Con­trol last year.

The con­sor­tium is a lead­ing plat­form for sci­en­tists from more than 100 coun­tries to dis­cuss mea­sures to tackle an­timi­cro­bial re­sis­tance.

“The award demon­strates that global in­fec­tious dis­ease ex­perts are giv­ing the nod to our non-an­tibi­otic ap­proach. They see it as a promis­ing way to pos­si­bly iron out prob­lems aris­ing from ram­pant drug-re­sis­tant bac­te­ria,” Kao said.

Con­tact the writer at hon­eyt­sang@chi­nadai­lyhk.com

PHO­TOS BY CALVIN NG / CHINA DAILY

Richard Kao Yi-tsun, as­so­ciate pro­fes­sor at the De­part­ment of Mi­cro­bi­ol­ogy at the Univer­sity of Hong Kong, dis­cov­ered a non-an­tibi­otic com­pound that may beat MRSA. emerged in 1940 staphy­lo­coc­cus

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